generator development: up-to-date recovery technologies for increasing the effectiveness of

Review Article99mTc Generator Development Up-to-Date 99mTc RecoveryTechnologies for Increasing the Effectiveness of 99Mo Utilisation

Van So Le

MEDISOTEC and CYCLOPHARM Ltd 14(1) Dwyer Street Gymea NSW 2227 Australia

Correspondence should be addressed to Van So Le vansole01gmailcom

Received 30 June 2013 Accepted 5 August 2013 Published 16 January 2014

Academic Editor Pablo Cristini

Copyright copy 2014 Van So Le This is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

A review on the 99Mo sources available today and on the 99mTc generators developed up to date for increasing the effectiveness of99Mo utilisation is performed in the format of detailed description of the features and technical performance of the technologicalgroups of the 99Mo production and 99mTc recovery The latest results of the endeavour in this field are also surveyed in regard ofthe technical solution for overcoming the shortage of 99Mo supply The technological topics are grouped and discussed in a way toreflect the similarity in the technological process of each group The following groups are included in this review which are highspecific activity 99Mo the current issues of production the efforts of more effective utilisation and the high specific activity 99Mo-based 99mTc generator and 99mTc concentration units low specific activity 99Mo the 99Moproduction based on neutron capture andaccelerators and the direct production of 99mTc and the methods of increasing the specific activity of 99Mo using Szilard-Chalmersreaction and high electric power isotopic separator up-to-date technologies of 99mTc recovery from low specific activity 99Mo thesolvent extraction-based 99mTc generator the sublimation methods for 99Mo 99mTc separation the electrochemical method for99mTc recovery and the column chromatographic methods for 99mTc recovery Besides the traditional 99mTc-generator systemsthe integrated 99mTc generator systems (99mTc generator column combined with postelution purificationconcentration unit) arediscussed with the format of process diagram and picture of real generator systems These systems are the technetium selectivesorbent column-based generators the high Mo-loading capacity column-based integrated 99mTc generator systems which includethe saline-eluted generator systems and the nonsaline aqueous and organic solvent eluent-eluted generator systems using highMo-loading capacity molybdategel and recently developed sorbent columns 99mTc concentration methods used in the 99mTcrecovery from low specific activity 99Mo are also discussed with detailed process diagrams which are surveyed in two groupsfor 99mTc concentration from the saline and nonsaline 99mTc-eluates The evaluation methods for the performance of 99mTc-recoveryconcentration process and for the 99mTc-elution capability versus Mo-loading capacity of generator column producedusing low specific activity 99Mo source are briefly reported Together with the theoretical aspects of 99mTc99Mo and sorbentchemistry these evaluationassessment processes will be useful for any further development in the field of the 99mTc recoveryand 99Mo 99mTc generator production

1 Introduction

The development of the original 99mTc generator was carriedout by Walter Tucker and Margaret Greens as part ofthe isotope development program at Brookhaven NationalLaboratory in 1958 [1] 99mTc is currently used in 80ndash85 ofdiagnostic imaging procedures in nuclear medicine world-wide every year This radioisotope is produced mainly fromthe 99mTc generators via 120573-particle decay of its parent nuclide99Mo 99Mo nuclide decays to 99mTc with an efficiency of

about 886 and the remaining 114 decays directly to 99TcA 99mTc generator or colloquially a ldquotechnetium cowrdquo isa device used to extract the 99mTc-pertechnetate generatedfrom the radioactive decay of 99Mo (119879

12= 667 h) As such

it can be easily transported over long distances to radiophar-macies where its decay product 99mTc (119879

12= 6 h) is extracted

for daily use 99Mo sources used in different 99mTc generatorsare of variable specific activity (SA) depending on the pro-duction methods applied Based on the nuclear reaction data

Hindawi Publishing CorporationScience and Technology of Nuclear InstallationsVolume 2014 Article ID 345252 41 pageshttpdxdoiorg1011552014345252

2 Science and Technology of Nuclear Installations

Table 1 Current application of 99mTc for clinical SPECT imaging and activity dose requirement (lowast) The injection activity dose (mCi 99mTc)normally delivered in 1mL solution of the 99mTc-based radiopharmaceutical [167]

Organ99mTc

radiopharmaceuticalInjection activity

dose (lowast) Organ99mTc


dose (lowast)

Brain99mTc-ECD 10ndash20mCi

Kidney

99mTc-MAG3 5ndash15mCi99mTc-ceretec (HmPAO) 10ndash2mCi 99mTc-DTPA 5ndash15mCi

Lung

99mTc-MAA 2ndash4mCi 99mTc-Gluceptate 5ndash15mCi99mTc-DTPA aerosol 30mCi3mL

(10mCimL)99mTc-DMSA 2ndash5mCi

99mTc-Technegas 100ndash250mCimL Skeleton99mTc-MDP 10ndash20mCi

Thyroid 99mTc-pertechnetate 5ndash10mCi 99mTc-HDP 10ndash20mCi

Liver99mTc-IDA 5ndash10mCi

Heart

99mTc-Sestamibi 10ndash30mCi99mTc-sulfuralbumine

colloid 5ndash15mCi 99mTc-PYP 10ndash15mCi

Spleen99mTc-sulfuralbumine

colloid 2-3mCi 99mTc-Tetrofosmin 5ndash25mCi99mTc-red blood cells 2-3mCi Tumour 99mTc-Sestamibi 15ndash20mCi

available today two types of 99Mo sources of significantly dif-ferent SA values (low and high SA) can be achieved using dif-ferent 99Mo production ways Accordingly 99mTc generatorsusing low or high SA 99Mo should be produced by suitabletechnologies to make them acceptable for nuclear medicineuses The safe utilisation of the 99mTc generators is definitelycontrolled by the quality factors required by the healthauthorities However the acceptability of the 99mTc generatorto be used in nuclear diagnostic procedures the effectiveutilisation of 99mTc generator and the quality of 99mTc-basedSPECT imaging diagnosis are controlled by the generatoroperationelution management which is determined by the99mTc concentration of the 99mTc eluatesolution This alsomeans that the efficacy of the 99mTc generator used in nuclearmedicine depends on the 99mTc concentration of the solutioneluted from the generator because the volume of a giveninjection dose of 99mTc-based radiopharmaceutical is limitedThecurrent clinical applicationsof 99mTcare shown inTable 1As shown the injection dose activity of 99mTc-based radio-pharmaceutical delivered in 1mL solution is an importantfactor in determining the efficacy of the 99mTc solutionproduced from the generators So it is clear that the 99mTcconcentration of the solution eluted from the generator is theutmost important concern in the process of the generatordevelopment irrespectively using either fission-based highspecific activity 99Mo or any 99Mo source of low specificactivity It is realised that a complete review on the 99Mo and99mTc productiondevelopmentmay contribute and stimulatethe continuing efforts to understand the technological issuesand find out the ways to produce a medically acceptable99Mo99mTc generator and to overcome the shortagecrisis of99Mo99mTc supply So this review is to give a complete surveyon the technological issues related to the production anddevelopment of high and low specific activity 99Mo and to theup-to-day 99mTc recovery technologies which are carried outin many laboratories for increasing the effectiveness of 99Mo

utilisation The evaluation methods for the performance ofthe 99mTc-recoveryconcentration process and for the 99mTc-elution capability versusMo-loading capacity of the generatorcolumn produced using (119899 120574)99Mo (or any low specificactivity 99Mo source) are briefly reported Together with thetheoretical aspects of 99mTc99Mo and sorbent chemistrythese evaluationassessment processes could be useful for anyfurther development in the field of the 99mTc recovery and99Mo99mTc generator production The achievements gath-ered worldwide are extracted as the demonstrative examplesof today progress in the field of common interest as well

2 High Specific Activity 99Mo CurrentIssues of Production and Efforts of MoreEffective Utilisation

21 Production of High Specific Activity 99Mo High SA 99Mois currently produced from the uranium fission The fissioncross-section for thermal fission of 235U is of approximately600 barns 37 barns of this amount result in the probability ofa 99Mo atom being created per each fission event In essenceeach one hundred fission events yields about six atomsof 99Mo (61 fission yield) Presently global demand for99mTc is met primarily by producing high specific activity(SA) 99Mo from nuclear fission of 235U and using mainlyfive government-owned and funded research reactors (NRUCanada HFR the Netherland BR2 Belgium Osiris FranceSafari South Africa) After neutron bombardment of soliduranium targets in a heterogeneous research reactor thetarget is dissolved in a suitable solution and the high SA99Mo is extracted purified and packed in four industrialfacilities (MDS Nordion Canada Covidien the NetherlandIRE Belgium NTP South Africa) and supplied to manu-facturers of 99mTc generators around the world [2ndash12]CNEAINVAP (Argentina) ANSTO (Australia) Russia and

Science and Technology of Nuclear Installations 3

BATAN (Indonesia) also produce fission 99Mo and total sup-ply capacity of these facilities is about 5 of the globaldemand of 99Mo [3]The weekly demand of 99Mo is reportedto be approximately 12000Ci at the time of reference (6-dayCi)This is equivalent to 69300Ci at the end of bombardment(EOB) All five of the major production reactors use highlyenriched uranium (HEU) targets with the isotope 235Uenriched to as much as 93 to produce 99Mo (except Safari1 in South Africa which uses 45 HEU) As mandated bythe US Congress non-HEU technologies for 99Mo and 99mTcproduction should be used as a Global Initiative to CombatNuclear Terrorism (GICNT) [13 14] The 99Mo productionplans for conversion of HEU to low enriched uranium (LEU)based technology using heterogeneous research reactorsachieved a major milestone in years 2002ndash2010 and cur-rently the production of high SA 99Mo from LEU targets isroutinely performed in Argentina (from 2002) in Australia(from 2009) and in South Africa (from 2010) CNEANVAP (Argentina) is a pioneer in the conversion of HEU toLEU by starting LEU-based 99Mo production in 2002 afterdecommissioning of HEU technology which has been oper-ated 17 years ago [15 16] INVAP also demonstrated thematu-rity of LEU technology via technology transfer to ANSTOfor a modest industrial scale manufacture of a capacity of300ndash500 6-day curies per batch With an announcementlast year on a great expansion of production capacity ofLEU-based facility being started in 2016 in Australia [17]ANSTO and CNEAINVAP will become the first organisa-tions confirming the sustained commercial large-scale pro-duction of 99Mo based on LEU technology High SA 99Mois of approximately 50000Ci 99Mog of total Mo atEOB (The OPAL reactor Australia thermal neutron flux91013 ncmminus2 secminus1) irrespectively using either HEU or LEU-based fission technologies With the effort in maintaining thesupply of high SA 99Mo several alternative non-HEU tech-nologies are being developed Fission of 235Utoproduce 99Mois also performed using homogeneous (solution) nuclear reac-tor and 99Mo recovery system so-calledMedical Isotope Pro-duction System (MIPS) [18] The reactor fuel solution in theform of an LEU-based nitrate or sulphate salt dissolved inwater and acid is also the targetmaterial for 99MoproductionIn essence the reactor would be operated for the timerequired for the buildup of 99Mo in the fuel solution At theend of reactor operation the fuel solution pumped throughthe 99Mo-recovery columns such as Termoxid 52 Termoxid5M titana PZC sorbent and alumina which preferentiallysorbs molybdenum [19 20] The 99Mo is then recovered byeluting the recovery column and subsequently purified by oneormore purification steps It is estimated that a 200 kWMIPSis capable of producing about 10000Ci of 99Mo at the end ofbombardment (five-day irradiation) [2 18 21]The possibilityof using the high power linear accelerator-driven proton (150ndash500MeV proton with up to 2mA of beam current sim1016particless) to generate high intensities of thermal-energyneutrons for the fission of 235U inmetallic LEU foil targets hasbeen proposed [2 22] This accelerator can produce an orderofmagnitudemore secondary neutrons inside the target from

fission The low energy accelerator (300 keV deuteron with50mA of beam current)-based neutron production via theDT reaction for the fission of 235U in LEU solution tar-gets has been reported [2] The fission of 235U for the 99Moproduction can be performed with neutrons generated fromthe gt2224MeV photon-induced breakup of D2O in a sub-critical LEU solution target Accelerator-driven photon-fis-sion 238U(120574f) 99Mo is also proposed as an approach to pro-duce high SA 99Mo using natural uranium target [2 23ndash25]

Under the consultation for the fission 99Mo plant inANSTO the author of this review paper has proposed aproject of ldquoAutomated modular process for LEU-based produc-tion of fission 99119872119900rdquo [26]The consent of the Chief ExecutiveOfficer of ANSTO is a positive signal that might get scientistsahead of the game with next generation (cheaper better andfaster) Mo-99 plant design The aim of this project is toprovide the integrated facility composed of automated com-pact high technology modules to establish medium-scaleproduction capability in different nuclear centres runningsmall reactors around the world In essence this project is todecentralize the 99Mo productionsupply and the radioactivewaste treatment burden in the large facilities and to bring99Mo production closer to users (99mTc generator manufac-turers) to minimize the decay 99Mo loss The modular tech-nology-based production is standardized for the secure oper-ation sustainable with the supply of replaceable standard-ized modulescomponents for both 99Mo processing andradioactive waste treatmentThe above-mentioned objectivesare in combination to solve basically the 99Mo undersupplyproblem or crisis by increasing the numbers of smaller 99Moprocessing facilities in hundreds of nuclear centres owning99Mo production-capable reactors in the world and to reducethe cost of 99Mo for patient use The brief of the modular99Mo technology is the following Currently three mainmedical radioisotopes 99Mo 131I and 133Xe are routinely pro-duced from uranium fission So it is conceivable to saythat the fission uranium based medical isotope productionfacility is composed of 6 main technological modules targetdigestion module 99Mo separation module 131I separationmodule 133Xe separationmodule uranium recoverymoduleand waste treatment modules (gas solid and liquid wastemodules) For 99Mo production alone the numbers of mainmodules can be reduced to 4 comprising main module foruranium target digestion main module for 99Mo separationmain module for uranium recovery main module for wastetreatment (gas solid and liquid waste modules)

Each main module in this description is composed ofseveral different functional modules As an example themain module for 99Mo separation incorporates 7 functionalmodules such as five ion exchange resinsorption func-tional modules and two solution delivery functional modules(radioactive and nonradioactive)

A pictorial description of the structure of one mainmodule which is capable of incorporating five functionalmodules (below illustrated with two functional modules asexamples) is shown in Figure 1


Fluid control unit

Chelex resincolumn

Tubingconnection port

Electricalconnection

port

Main module motherboard withslots of plug-in for the

Slot for onefunctional module

Solution deliveryfunctional module

functional modulesfunctional modulePurification step 5

eg chelex resinpurification

Figure 1 Conceptual diagram of the modular technology of fission-99Mo recovery [26]

The operation of this main module is automated andcomputerized The integrated fluid flow and radioactivitymonitoring system using photo andor radiation diodesensors provides the feedback information for safe andreliable process control The in-cell maintenance based onthe replacement of failed functional module is completedquickly ensuring continuous production run Advantages ofthis facility setup are the following compact system withcontrollable and reliable process less space required thatminimizes the cost of the facility (one double-compartmenthot cell for whole process) minimal maintenance workrequired that due to highly standardizedmodular integrationhigh automation capability low cost production of 99Momaking this modular technology feasible for small nuclearresearch centres in many countries of the world centralizingthe module supply and maintenance giving high securityand sustainability of production to small producers withfew resources high capability of the network-based 99Moproductionsupply to overcome any global 99Mo crisis

TheW impurity inmassive LEU targets is still challengingthe quality of 99Mo obtained from different 99Mo recoveryprocesses because the WO

4

2minus ions and radioactive impurity(188Re) generated from neutron-activated W cause seriousproblems in the 99mTc generator manufacture and in the useof 99mTc-pertechnetate solution respectively The effort to

remove W impurity from the 99Mo solution produced fromLEU target is being performed as shown in Figure 2 [27]

22 High Specific Activity Fission 99Mo-Based 99mTc Genera-tors and Concentrators The isolation of 99Mo from uraniumfission typically generates 99Mowith a specific activity greaterthan gt10000Cig at the six-day-Ci reference time (specificactivity of carrier-free 99Mo is 4744640 Cig [28]) ThisSA value permits extraction of the 99mTc daughter nuclideusing chromatographic alumina column [1 29ndash35] Todaymost commercial 99mTc generators are designed by takingadvantage of much stronger retaining of the MoO

4

2minus anionscompared with the TcO

4

minus anions on acidic alumina sorbentAlthough the adsorption capacity of the alumina for MoO

4

2minus

anions is low (lt10mgMog) the very low content of Mo inthe high SA 99Mo solution (01mg Mo per Ci 99Mo) whichis loaded on a typical column containing 2-3 g of aluminafor a 4Ci activity generator ensures a minimal 99Mo break-through in the medically useful 99mTc-pertechnetate solutionextracted from the generator system When the 99Mo decaysit forms pertechnetate (99mTcO

4

minus) which is easily elutedwith saline solution from the alumina column resulting aninjectable saline solution containing the 99mTc in the form ofsodium-pertechnetate The most stable form of the radionu-clide 99mTc in aqueous solution is the tetraoxopertechnetate


W in H2SO4

Mo in H2SO4

001 01 1 101

10

100

1000

10000

100000

1000000

kd

(mL

g)

H2SO4 (M)

(a)

0

1

2

3

4

5

6

5 10 15 20Elution volume (mL)

99M

o or

188W

radi

oact

ivity

(120583Ci

)

WMo

(b)

Figure 2WMo adsorption and separation using alumina column (a)weight distribution coefficients ofWO4

2minus andMoO4

2minus ions on aluminaversus acidity of H

2SO

4solution (b) elution profile of WO

4

2minus andMoO4

2minus ions (column 1 g alumina eluent 6MH2SO

4for MoO

4

2minus elutionand 1M NH

4OH for WO

4

2minus stripping loading solution 8mg Mo + 10mgW) [27]

anion The most important requirement for the design of analumina column-based 99mTc recovery system is that it mustexhibit both a high elution efficiency (typically gt85) andminimal 99Mo breakthrough (lt0015) [36 37] The gener-ators are sold on the world market with different sizes from200mCi to 4000 mCi and the elution of 99mTc is performedwith 5ndash10mL normal saline Fission 99Mo-based 99Mo99mTcgenerators commercially available in theUS are of the activityrange between 02 Ci and 40 Ci at the six-day curies referencetime and in ANSTO (Australia) between 045 Ci to 32 CiThe cost-effective utilisation of a 99Mo99mTc generator andthe quality of 99mTc based single photon emission computedtomography (SPECT) imaging diagnoses is controlled by thegenerator operationelutionmanagementTheprimary factorpertaining to the nuclear medicine diagnostic scansrsquo qualityis the concentration of 99mTc obtained from the 99Mo99mTcgenerator elution which is expressed as activity per mL Theinjection dose activity of 99mTc-based radiopharmaceuticalsdelivered in 1mL solution (99mTc-concentration mCimL)is an important factor in determining the useful life timeof the 99mTc generators and the quality of 99mTc basedSPECT imaging diagnosis as well Generally a 99mTc eluate isproduced from the 99Mo99mTc generator in fixed volume andthe concentration of the 99mTc in the eluted solution decreaseswith the life time of the 99Mo99mTc generator due to theradioactive decay of the parent nuclide 99Mo Consequentlythe useful life time of the generator is also a function ofavailable 99mTc concentration of the eluate If we considerthat the value 10ndash20mCi of 99mTc per mL is used as a limitof the medically useful 99mTc solution the assessment of the99mTc generator utilisation effectiveness shows the following

wasted residual activity of a used generator of 2 Ci activityeluted with 10mL saline is 5ndash10 of its total activity whilesmaller generators of 500mCi activity waste up to 20ndash40 In case of the concentrator used to increase the 99mTcconcentration of the eluate eluted from these generators allthe activity of the generator will efficiently be exploited Sothe radioisotope concentrator device should be developedto increase the concentration and quality of injectable 99mTceluates and consequently the generator life time or theeffectiveness of the generator utilisation Some concentra-tion methods have been developed for increasing 99mTcconcentration of the saline eluate for extension of the lifetime of the fission-99Mo-based 99mTc generators [38ndash44] Allthese methods used a chloride-removing column containingAg+ ions which couple with a pertechnetate-concentratingsorbent column such as alumina Bonelut-SAX QMA andmultifunctional sorbent Alternative concentration methodshave also been developed The alternatives are based onthe elution of the alumina column of the generator witha nonchloride aqueous eluent (such as ammonium-acetatesolution and less-chloride acetic acid solution) or with anonchloride organic eluent (such as tributylammonium-bromide and acetone solvent) 99mTc-pertechnetate of thiseluate is concentrated using a sorbent column (concentra-tion column) or an organic solvent evaporator respectivelyThen 99mTc-pertechnetate is recovered in a small volume ofnormal saline for medical use [45ndash60] These methods havesignificantly increased the life time of the generators Theuse of nonchloride eluent in replacement of saline normallyused in a commercial generator may not be preferable due tolegal issues of the amended registration requirement Unfor-tunately no concentrator device prototypes developed based


0 10 20 30 40 50 600

5

10

15

20

25

30

35

40

45

50

0

50

100

150

200

250

300

350

400

450

500

Radi

oact

ivity

(Ci)

Time (h)

99

mTc

spec

ific r

adio

activ

ity (C

i120583m

ol)

A

B

C

ti=1 ti=2 ti=3 ti=4 = tmax

D

E

ATc minus 99m(max)

(a)

0 5 10 15 20 25

Elution time tb (h)

0

05

1

15

2

25

3

Yiel

d ra

tio (R

y)

(b)

(c) (d)

Figure 3 Radioisotope concentrator ULTRALUTE (patent-pending) and Effectiveness of 99mTc99Mo utilisation (a) kinetics of radioactivedecay99mTc-activity buildup in the generator eluted with an early elution regime (A 99Mo-activity B 99mTc-activity buildup from beginningC 99mTc-activity growth after first elution D 99mTc-activity growtheluted at 6-hour elutions E 99mTc-SA in the system of 99mTc-radioactivitybuildup from beginning) [58] (b) effectiveness of ldquoearlyrdquo elution regime for increasing 99mTc-elution yield of the generator compared withthat normally eluted at the time point of maximal 99mTc-buildup (square is experimental and dashed line is theoretical calculation result)[58] (c) ULTRALUTE concentrator device [41 61] (d) ULTRALUTE concentrator device inline-coupled with a 99mTc generator

on the developed methods are commercially available up todate Recently Cyclopharm Ltd (Australia) in cooperationwith Medisotec (Australia) has developed a 99mTc 188Reconcentrator device ULTRALUTE [40ndash42] using a new sor-bent as a concentrator column coupled with the saline-elutedcommercial generator This device (Figures 3(c) and 3(d)) isa sterile multielution cartridge which is operatedeluted byevacuated-vial through disposable sterile filters to increasethe 99mTc concentration of the saline eluate of aged commer-cial 99mTc generators The increase in 99mTc concentrationin the eluate enhances the utilisation of 99mTc in Techne-gas generator-based lung perfusion (100ndash250mCimL) andother SPECT (20ndash30mCimL) imaging studies The 99mTc-pertechnetate of the generator eluate was concentrated morethan 10-fold with a 99mTc recovery yield of gt85 usingthis radioisotope concentrator device Five repeated elutionswere successfully performed with each cartridge So each

cartridge can be effectively used for one week in dailyhospital environment for radiopharmaceutical formulationThe useful lifetime of the 99mTc generator was significantlyextended depending on the activity of the generator as shownin Table 2The 99Mo impurity detectable in the 99mTc solutiondirectly eluted from Gentech generator was totally elimi-nated by this radioisotope concentrator device and ultrapureconcentrated 99mTc-pertechnetate solution was achievedTheconcentrated 99mTc solution is well suited to labeling invivo kits and to loading the crucibles of Technegas aerosolgenerator for VQ SPECT imaging The useful life time ofthe 99mTc generator (Table 2) was significantly extended from10 to 20 days for the generators of 300ndash3000mCi activityrespectively This means that about 20 of the generatoractivity is saved by extending the life time of the generatorBesides that about 20 of the generator 99mTc-activity can besaved as a result of the extension of 99mTc-generator life time


the use of radioisotope concentrator for the optimization ofgenerator elution to increasing the 99mTc-activity yield andthe effectiveness of 99Moutilizationwas reported by Le (2013)[58 61] This fact is shown as follows 99mTc continuouslydecays to 99Tcduring his buildup from the decay of 99MoThisprocess not only reduces the 99mTc-activity production yieldof the generator (ie a large quantity of 99mTc activity wastedduring 99mTc activity buildup results in a lower 99mTc-activityproduction yield of the generator so it is noneconomicallyexploited) but also makes the specific activity (SA) of 99mTccontinuously decreased The low SA may cause the labellingquality of 99mTc eluate degradedThis means that the elutionsof the generator at a shorter build-up time of daughternuclide will result in a higher accumulative daughter-activityproduction yield (more effectiveness of 99mTc99Mo activityutilisation) and a better labelling quality of the generatoreluate Accumulative production yield is the sum of all theyields achieved in each early elution performed before themaximal build-up time However each early 99mTc-elution atshorter build-up time (ldquoearlyrdquo elution) will result in a lower99mTc-elution yield and thus yields an eluate of lower 99mTc-concentration because 99mTc is eluted from the generator infixed eluent volume These facts show that a high labellingquality solution of clinically sufficient 99mTc concentrationcould be achieved if the generator eluate obtained at an ldquoearlyrdquoelution is further concentrated by a certified radioisotopeconcentrator device

A general method described in previous work of VS Le and M K Le [58] was applied for evaluation ofthe effectiveness of ldquoearlyrdquo elution regime in comparisonwith a single elution performed at maximal build-up timepoint of the radionuclide generators For this evaluation thedaughter nuclide-yield ratio (119877

119910) is set up and calculated

based on quotient of the total of daughter nuclide-elutionyields (sum119894=119899

119894=1119860119889(119864119894)

) eluted in all 119894 elutions (119864119894is the index for

the 119894th elution) divided by the maximal daughter nuclide-yield or daughter nuclide-activity (119860

119889(Max)) which could beeluted from the generator at maximal build-up time 119905Max119877119910

= sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)

Starting from the basic equation of radioactivity buildupyield (119860

119889) of a daughter nuclide and the maximal build-

up time (119905Max) for attaining the maximal activity buildup ofdaughter nuclide radioactivity growth-in in a given radio-nuclide generator system the equation for calculation ofdaughter nuclide-yield ratio (119877

119910) was derived as follows [58]

119877119910

=sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)

=sum119909=119894minus1

119909=0[119890minus120582119901 sdot119909sdot119905119887 times (119890minus120582119901 sdot119905119887 minus 119890minus120582119889 sdot119905119887)]

(119890minus120582119901 sdot119905Max minus 119890minus120582119889 sdot119905Max)

(1)

(The subscripts 119901 and 119889 in the above equations denote theparent and daughter radionuclides resp)

As an example the details of the case of 99mTc99Mogenerator system are briefly described as follows

numbers of radioactive 99Mo nuclides

119873Mo = 1198730Mo times 119890minus120582Mo sdot119905 (2)

Radioactivity of 99mTc nuclides in the generator

119860Tc-99m = 120582Tc-99m times 1198730Mo times 119887

times (120582Mo

120582Tc-99m minus 120582Mo) times (119890minus120582Mo sdot119905 minus 119890minus120582Tc-99m sdot119905)

(3)

the maximal build-up time (at which the maximal 99mTc-activity buildupyield in 99Mo99mTc generator system isavailable)

119905Max =[ln (120582Tc-99m120582Mo-99)]

(120582Tc-99m minus 120582Mo-99) (4)

Numbers of Tc atoms at build-up time

119873Tc = 119873Tc-99 + 119873Tc-99m

= 1198730Mo minus 119873Mo = 119873

0Mo times (1 minus 119890minus120582Mo sdot119905)

(5)

Specific activity of carrier-included 99mTc in the 99mTc gener-ator system or 99mTc-eluate is calculated using (3) and (5) asfollows

119878119860Tc-99m

=119860Tc-99m

119873Tc

=120582Tc-99m sdot 119887 sdot (119890minus120582Mo sdot119905 minus 119890minus120582Tc-99m sdot119905)

06144 times 10minus7 times ((120582Tc-99m120582Mo) minus 1) times (1 minus 119890minus120582Mo sdot119905)

(Cimol)

(6)99119898119879119888-Yield Ratio (119877

119910) Calculation for Multiple ldquoEarlyrdquo Elu-

tion Regime The 119877119910value is calculated based on quotient of

the total 99mTc-elution yields eluted (or 99mTc-activity pro-ducedused for scans) in all 119894 elution numbers (119864

119894is the index

for the 119894th elution) divided by the maximal 99mTc-activity(119860Tc-99m(Max)) which would be eluted from the generator atmaximal build-up time 119905Max

The total 99mTc-elution yields eluted in all 119894 elutions arethe sum of 99mTc-radioactivities at a different elution number119894 (119860Tc-99m(119864119894)) This amount is described as follows119894=119899

sum119894=1

119860Tc-99m(119864119894) = 120582Tc-99m times119894=119899

sum119894=1

119873Tc-99m(119864119894)

= 120582Tc-99m

119909=119894minus1

sum119909=0

[1198730Mo times 119890minus120582Mo sdot119909sdot119905119887 times 119887

times (120582Mo

120582Tc-99m minus 120582Mo)

times (119890minus120582Mo sdot119905119887 minus 119890minus120582Tc-99m sdot119905119887) ]

(7)


Table 2 Performance of 99mTc radioisotope concentrator device ULTRALUTE (effect of concentrator on generator useful life) [41 61]

Generator activitymCi ( GBq)

Generator useful life for SPECT imaging days Generator useful life for lung imaging with Technegas daysWithout concentrator Postelution concentrator Without concentrator Postelution concentrator

100 (37) 1 6 0 1300 (111) 4 10 0 4500 (185) 6 12 0 61000 (370) 9 15 1 93000 (1110) 14 20 4 14

The maximal 99mTc-activity buildupyield in 99Mo99mTcgenerator system is described using (3) and (4) as follows

119860Tc-99m(Max) = 120582Tc-99m times 1198730Mo times 119887 times (

120582Mo120582Tc-99m minus 120582Mo

)

times (119890minus120582Mo sdot119905Max minus 119890minus120582Tc-99m sdot119905Max)

(8)

99mTc-yield ratio (119877119910) is derived from (7) and (8) as follows

119877119910

=sum119894=119899

119894=1119860Tc-99m(119864119894)

119860Tc-99m(Max)

=sum119909=119894minus1

119909=0[119890minus120582Mo sdot119909sdot119905119887 times (119890minus120582Mo sdot119905119887 minus 119890minus120582Tc-99m sdot119905119887)]

(119890minus120582Mo sdot119905Max minus 119890minus120582Tc-99m sdot119905Max)

(9)

where 119887 is the 99mTc-branch decay factor of 99Mo(119887 = 0875)119894 is the number of the early elutions needed for a practicalschedule of SPECT scans The build-up time (119905

119887) for each

elution is determined as 119905119887

= (119905Max119894) 119909 is the number of theelutions which have been performed before starting a 99mTc-build-up process for each consecutive elution At this startingtime point no residual Tc atoms left in the generator from apreceding elution are assumed (ie 99mTc-elution yield of thepreceding elution is assumed 100)

The results of the evaluation (Figures 3(a) and 3(b)) basedon (3) (6) and (9) show that the 99mTc-activity productionyield of the generator eluted with an early elution regime ofbuild-upelution time lt6 hours increases by a factor gt2 andthe 99mTc specific activity values of the eluates are remainedhigher than 160Ci120583mol

Obviously the radioisotope concentrator not only mayhave positive impact on the extension of useful life time ofthe generators but also is capable to increase both the 99mTc-activity production yield of the generatoreffectiveness of99mTc99Moutilisation and the specific activity by performingthe early elutions of the generator at any time before maximalbuildup of 99mTc

With the utilization of 99mTc concentrator device whichgives a final 99mTc-solution of 10mL volume the exper-imental results obtained from a 525mCi generator as anexample confirmed that the concentration and the yield of99mTc solution eluted with a 6-hour elution regime is muchbetter than that obtained from the elution regime performedat the maximal build-up time (2286 hours) Within first 6days of elution 99mTc-concentration of the generator eluates

is in the range 200ndash44mCimL and total 99mTc-activity elutedis 17157mCi for a 6-hour elution regime (including the zeroday elution) while the concentration of 83ndash182mCimL andthe total activity of 10151mCi are for the elution regimeperformed at the maximal build-up time respectively [5861] The effectiveness of this early elution mode was alsoconfirmed experimentally in the prior-of-art of 68Ga68Gegenerator [62ndash64]

3 Low Specific Activity 99Mo Current Issuesof Production and Prospects

99Mo99mTc generators can be produced using low specificactivity 99Mo Some technologies for producing low SA 99Mohave been established Unfortunately several alternativesare not yet commercially proven or still require furtherdevelopment Presently no nuclear reaction-based nonfissionmethod creates a 99Mo source of reasonably high ormoderatespecific activity The reason is that the cross-section of allthese types of nuclear reactions which are performed by boththe nuclear reactor and accelerator facility is low rangingfrom several hundreds ofmillibarns to lt116 barns comparedwith 99Mo-effective fission cross-section (37 barns) of 235U-fission used in the production of high SA 99Mo as mentionedabove As shown below SA of nonfission 99Mo producedfrom nuclear reactor and accelerator facilities is in a range of1ndash10 Cig Mo To produce the 99mTc generators of the sameactivity size (1ndash4Ci) as in case of high SA 99Mo mentionedabove the 99mTc recovery system capable for processing Mo-target of several grams weight should be available eventhough the enriched 98Mo andor 100Mo targets are usedinstead of natural Mo target [2]

31 99Mo Production Based on Reactor Neutron CaptureNeutron capture-based 99Mo production is a viable andproven technology established in the years 1960s There arethirty-five isotopes of molybdenum known today Of sevennaturally occurring isotopes with atomic masses of 92 9495 96 97 98 and 100 six isotopes are stable with atomicmasses from 92 to 98 100Mo is the only naturally occurringradioactive isotope with a half-life of approximately 80E18years which decays double beta into 100Ru All radioactiveisotopes of molybdenum decay into isotopes of Nb Tc andRu 98Mo 94Mo and 100Mo (with natural abundance 241925 and 96 resp) are themost common isotopes used in


the targetry for production of two importantmedical isotopes99mTc and 94Tc

High SA 99Mo cannot be produced via (119899 120574) reactionusing Mo targets because the thermal neutron cross-sectionfor the (119899 120574) reaction of 98Mo is relatively small at about013 barn a factor of almost 300 times less than that of the235U fission cross-section In this respect irradiation of Motargets in an epithermal neutron flux could be economicallyadvantageous with respect to producing higher SA 99MoTheepithermal neutron capture cross-section of 98Mo is about116 barn The assessment of reaction yield and SA of the Motargets irradiated with reactor neutrons [28 65] shows thatthe irradiation time needed to reach a maximum yield andmaximum SA in Mo targets is too long while the improve-ment in reaction yieldSA is insignificant due to the low cross-section of 98Mo(119899 120574)99Mo reactions Neutron capture-based99Mo production with an 8-day irradiation in a reactor of10E14 n sdot cmminus2 sdot secminus1 thermal neutron flux gives a 99Moproduct of low SA as evaluated at EOB as follows sim16 Ci99Mog of natural isotopic abundance molybdenum andor6Ci 99Mog of 98-enriched 98Mo target These values showa factor of 104 times less than that of fission-produced high SA99Mo as mentioned above The loose-packed MoO

3powder

(density of gt 25 gcm3) pressedsintered Mo metal powder(density of lt 975 gcm3) and granulated Mo metal can beused as a target material High-density pressedsintered 98Mometal targets are also commercially available for the targetryMoO

3powder can be easily dissolved in sodium hydroxide

Molybdenum metallic targets can be dissolved in alkalinehydrogen peroxide or electrochemically The metal formtakes more time to dissolve than the MoO

3powder form

However the advantage of usingMometal target is that largerweight of Mo can be irradiated in its designated irradiationposition in both the research and power nuclear reactors[66 67] The neutron flux depression in the MoO

3target

may cause decreasing in 99Mo production yield when a largetarget is used [68ndash70] The production capacities of 230 6-day Ciweek and 1000 6-day Ciweek are estimated for theirradiation with JMTR research reactor in Oarai and with apower reactor BWR of Hitachi-GE Nuclear Energy Ltd inJapan respectively [66 71] The use of enriched 98Mo targetmaterial of 95 isotopic enrichment offers the 99Mo productof higher SA The W impurity in the natural Mo targetmaterial should be lt10 ppm and that is not detectable in theenriched 98Mo targets Due to high cost of highly enriched98Mo the economical use of this target material requires awell-established recycling of irradiated target material [2 2425 66 67 72ndash74]

32 Accelerator Based 99Mo99mTc Production All of theaccelerator-based nonfission approaches rely on highlyenriched 100Mo target While the 99 enrichment 100Mo issufficient for all accelerator-based 99Mo productions thedirect production of 99mTc may require enrichments exceed-ing gt995 due to the possible side reactions which generatelong-lived technetium and molybdenum isotopes becausethese impure radionuclides would cause an unnecessary

radiation dose burden to the patient and the waste disposalissues as wellThe SAof 99Moproduced from the acceleratorsis too low for use in existing commercial 99mTc generatorsystems that use alumina columns New 99mTc recoverytechnology that is suitable for processing the acceleratortargets of low specific activity 99Mo and allowing effectiverecycling of 100Mo should be developed [2]

While the specific activity of 99Mo produced using accel-erators (ranging up to 10 Cig at EOB) is not significantlyhigher than that of 99Mo produced by neutron capture usingnuclear reactor the 99Mo production using accelerator ispresently focused in many research centres with regards toits safer and less costing operation compared with nuclearreactor operation It is important to be addressed that allof the accelerator-based nonfission-99Mo production routesneed a well-established technology for recycling of the 100Motarget material This will be somewhat complicated since the100Mo targetmaterial is contaminatedwith the 99Mo left fromthe used 99mTc generator systems Handling this materialpresents some complicated logistics in that the targetmaterialwill have to be stored until the level of 99Mo is sufficiently lowso as to not present radiation handling problems Moreoverthe purification of the used 100Mo targetmust be addressed toensure completely removing all impurities which are broughtfrom the chemicals and equipment used in the productionprocesses

321 Photon-Neutron Process 100Mo(120574 119899)99Mo High energyphotons known as Bremsstrahlung radiation are producedby the electron beam (50MeV electron energy with 20ndash100mA current) as it interacts and loses energy in a high-Zconverter target such as liquidmercury or water-cooled tung-sten The photon-neutron process is performed by directingthe produced Bremsstrahlung radiation to another targetmaterial placed just behind the convertor in this case 100Moto produce 99Mo via the 100Mo(120574 119899)99Mo reaction (maximalcross-section around 170 millibarns at 145MeV photonenergy [25]) Although the higher SA 99Mo (360Cig) canbe achieved with a smaller weight target (sim300mg 100Mo)the 99Mo produced based on a routine production base has amuch lower SA approximately 10 Cig [75]

322 Proton-Neutron Process 100Mo(119901 119901119899)99Mo 30MeVcyclotron can be used for 99Mo production based on 100Mo(119901 119901119899)99Mo reaction (maximal cross-section around 170millibarns at 24MeV proton energy) 99Mo production yieldof lt50Ci can be achieved with a bombardment current 500mA for 24 hours [76ndash79]

323 Neutron-Neutron Process 100Mo(119899 119899119899)99Mo 99Mo pro-duction based on 100Mo(119899 2119899)99Mo reaction (maximal cross-section around 1000 millibarns at 14MeV neutron energy)using fast neutron yielded from the 119863(119879 119899) reaction Theestablished targetry sufficient flux of neutrons and improve-ment in 99mTc separation are issues to be addressed for furtherdevelopment [80]


324 Direct Production of 99mTc The first report on the fea-sibility of producing 99mTc by proton irradiation of 100Mostated that a theoretical yield of 15 Ci 99mTc per hour canbe achieved with 22MeV proton bombardment at 455 120583A[81] More recently Takacs et al found a peak cross-sectionof 211 plusmn 33mb at 157MeV [79] Scholten and colleaguessuggested that the use of a gt17MeV cyclotron could be con-sidered for regional production of 99mTc with a productionyield of 1028mCi120583A at saturation [78] Estimated yield of99mTc production based on a routine production basis is 13 Ci99mTc (at EOB) using 18MeV proton beam of 02mA currentfor a 6-hour irradiation A irradiation of highly enriched100Mo target (pressedsintered metallic 100Mo powder) usingGE PET Trace cyclotron (165MeV proton beam 004mAcurrent and 6-hour bombardment) at Cyclopet (CyclopharmLtd Australia) can achieve gt20 Ci 99mTc at EOB as reportedby Medisotec (Australia) Using gt995 enriched 100Motarget produces very pure 99mTcThe 99mTc product ofgt996radionuclide purity can be achievedThemajor contaminantsinclude 99gTc 95Tc and 96Tc Trace amounts of 95Nb areproduced from the 98Mo(119901 120572)95Nb reaction [75ndash83]

33 Methods of Increasing the Specific Activity of 99Mo

331 Szilard-Chalmers Recoiled 99Mo A method to increasethe specific activity of neutron activated 99Mo in the naturalandor enriched Mo targets using Szilard-Chalmers recoiledatom chemistry was recently reported by the scientists at theDelft University of Technology in the NetherlandThe targetsused in this process are 98Mo containing compounds such asmolybdenum(0)hexacarbonyl [Mo(CO)

6] and molybdenum

(VI)dioxodioxinate [C4H3(O)ndashNC

5H3)]2ndashMoO

2 molybde-

num nanoparticles (sim100 nm) and other molybdenum tri-carbonyl compounds The neutron irradiated targets are firstdissolved in an organic solvent such as dichloromethane(C

2H2Cl

2) chloroform (CH

3Cl) benzene (C

6H6) and tolu-

ene (CH3ndashC

6H5)Then the 99Mo is extracted from this target

solution using an aqueous buffer solution of pH 2ndash12 Thetarget material is to be recycled This process is currently inthe stage of being scaled up towards demonstration of com-mercial production feasibility The specific activity of 99Moincreased by a factor ofmore than 1000 was achieved makingthe specific activity of neutron capture-based 99Mo compara-ble to that of the high SA 99Mo produced from the 235Ufission So the 99Mo produced by this way can be used inexisting commercial 99mTc generator systems that use alu-mina columns [84 85]

332 High Electric Power Off-Line Isotopic Separator forIncreasing the Specific Activity of 99Mo A high power ionsource coupled to a high resolution dipole magnet would beused to generate beams ofMo ions and separate the respectiveisotopes with the aim of producing 99Mowith specific activityof greater than 1000Cigram The construction of a highpower off-line isotope separator to extract high specificactivity 99Mo that had been produced via 98Mo(119899 120574) andor100Mo(120574 119899) routes would allow for rapid introduction of

the 99Mo into existing supply chain The feedstock for theseparator system will be low specific activity 99Mo gen-erated from the thermal neutron capture of 98Mo or thephoton induced neutron emission on 100Mo The proposedsystem would have the advantage that the 99Mo producedwill fit directly into the existing commercial generator systemeliminating the use of HEU and LEU targets and can beused to generate the required target material (98Mo100Mo)during the separation process In addition it can be usedin conjunction with a neutron or photon sources to create adistributed low cost delivery system [2 86]

4 Up-to-Date Technologies of 99mTcRecovery from Low Specific Activity 99Mo99Mo99mTc Separation Methods 99mTcPurificationConcentration and 99mTcGenerator Systems

Unfortunately the low SA 99Mo produced using the meth-ods mentioned above contains the overwhelming excess ofnonradioactivemolybdenum so as the alumina columns usedin existing commercial 99mTc generator systems would besufficiently loaded to produce the medically useful 99mTcdoses because the 99mTc recovery from this 99Mo source oflow SA requires significantly more alumina resulting in alarge elution volumes Consequently a solution of low 99mTc-concentration is obtained from these generator systems Tomake a low SA 99Mo source useful for nuclear medicineapplication some 99mTc recovery technologies for producingmedically applicable 99mTc solution have been establishedUnfortunately several alternatives are not yet commerciallyproven or still require further development The primaryfactor pertaining to the nuclear medicine scansrsquo quality is theconcentration of 99mTc in the solution produced from the99Mo99mTc generator which is expressed as 99mTc activitypermLThe injection dose activity of 99mTc-based radiophar-maceuticals delivered in 1mL solution is an important factorin determining the efficacy of the 99mTc generators and thequality of 99mTc-based SPECT imaging diagnosis as well Sothe 99mTc recovery technologies should be developed so as asterile injectable 99mTc solution of high activity concentrationand low radionuclidic and radiochemicalchemical impurityis obtained

Up-to-date 99mTc recovery technologies fall into four gen-eral categories solvent extraction sublimation electrolysisand column chromatography

41 Solvent Extraction for 99Mo99mTc Separation and SolventExtraction-Based 99mTc Generator Systems Solvent extrac-tion is the most common method for separating 99mTc fromlow specific activity 99Mo dated back to the years 1980s Thesolvent extraction method can produce 99mTc of high puritycomparable to that obtained from alumina column-based99mTc generator loaded with fission-99Mo of high specificactivity Several extraction systems (extractant-solventback-extraction solution) using different extractant agents (such as


1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V

Figure 4 Diagram of MEK extraction-based 99Mo99mTc generator [60] 1 alkaline 99Mo-molybdate solution 2 MEK solvent 3 extractor4 MEK evaporator 5 saline 6 MEK receiver 7 condenser 8 99mTc solution receiver 9 Millipore filter 10 final 99mTc solution vial 11 acidicalumina column 12 70∘C water circulator v valve V vacuum line

ketones crow ethers trioctylamine tricapryl methyl ammo-nium chloride (Aliquat-336) liquid ion-exchangers andionic liquids) were investigated [35 60 87ndash91] Amongthe extractant compounds investigated methyl ethyl ketone(MEK) is the best for the extraction of 99mTc-pertechnetatein terms of high extraction yield high radiation stability andlow boiling temperature Generators based on MEK extrac-tion of 99mTc-pertechnetate from alkaline aqueousmolybdatesolutions have been widely used for the production of 99mTcThe extraction cycle consists of adding a mixture of MEKsolvent containing 1 aqueous hydrogen peroxide to the 5MNaOH solution of 99Mo target and mechanically stirring themixture to selectively extract the 99mTc from the aqueousphase into the MEK phase The hydrogen peroxide is addedto keep the 99Mo and 99mTc in the appropriate oxidation stateAfter standing of the mixture to allow the phase separationthe supernatant MEK99mTc solutionorganic phase contain-ing the extracted 99mTc is removed by sucking effected bya negative pressure and then it is passed through an acidicalumina to remove any 99Mo that may be coextractedwith 99mTc into the MEK solution In the following theMEK99mTc solution is transferred to an evaporation vessel(evaporator) The evaporator is heated to sim70∘C under aslight negative pressure to hasten the evaporation of theMEK After the MEK has been completely removed sterilesaline is added to the evaporator to recover the 99mTc inthe form of sodium-(99mTc) pertechnetate dissolved in thesaline This 99mTc saline solution is then sterilized by passingthrough aMillipore filter and transferred into a sterile vial forfurther processing at quality control and for formulating theradiopharmaceuticals

The centralized solvent extraction-based 99mTc generatorsystems have been successfully performed for more thandecade in Australia [92] and Czechoslovakia [6 35 93 94]

Some other systems are routinely used in Russia Peru andin Asian countries where the fission 99Mo-based chromato-graphic 99mTc generators donot enter the competition [60 8795ndash97] As an example a centralized extraction-based 99mTcgenerator used for many years in a hospital in Vietnam isshown in Figure 4 [60]

The shortage in the fission 99Mo supply today howeverhas encouraged the 99mTc users over the world to use moreeffectively the solvent extraction-based 99mTc as well So theless competitive solvent extraction-based 99mTc-generatorsystems developed several decades before should beupgraded to be used as a user-friendly prototype for a dailyuse in hospital environments The update solvent extraction-based 99mTc generator systems under development aredesigned for an automated or semiautomated operationbased either on the established extraction process [95 98ndash100] as mentioned above or on the improved extraction tech-nologiesThe improvement in the removing ofMEK from theextracted 99mTc-MEKorganic phase to obtain 99mTc-pertech-netate is essential in the updateMEK extraction technologiesbecause this will make the extraction being performed with99mTc recovery into a aqueous solution without the compli-cated step of MEK evaporation thus facilitating the processautomationThis improved technology is based on the none-vaporation removing of MEK by passing the extracted99mTc-MEK organic phase through a cation-exchange resinor basic alumina column coupled with an acidic aluminacolumn followed by a water wash to completely remove both99Mo contaminant and MEK Then the 99mTc pertechnetateretained on the acidic alumina column will be eluted with asmall volume of saline solution to achieve an injectable 99mTcpertechnetate solution This approach has been developed inJapan in 1971 [71 101 102] and recently resurrected in Indiaand Russia [95 99 100] The process is pictorially described


in Figure 5 A computerized compact module for 99mTcseparation based MEK extraction coupled with the MEKremoving unit which composes of a tandem of basicacidicalumina columns is developing in BRIT [100]

42 Sublimation Methods for 99Mo99mTc Separation andSublimation-Based 99mTc Generator Systems Three sublima-tionmethods for 99Mo99mTc separationhave beendevelopedand commercially used in past decades [6 35 66 70 71 9294 112 113] The first is the high temperature sublimationmethod developed at the end of the sixties and used for manyyears in Australia which is based on the heating a neutron-activated MoO

3target on gt800∘C in a furnace with oxygen

stream passed through The sublimed 99mTc in the form ofTc

2O7is condensed in the cold finger at the end of the furnace

and 99mTcO4

minus is isolated by rinsing the cold finger with a hot01mM NaOH solution followed by purification on aluminaSome modified versions of this method were performedto achieve higher 99mTc recovery yield The highest yieldobtained was around 80 with a sublimation time of 20ndash30minutesThe secondmethod is themedium temperature sub-limation This method relies on heating a eutectic mixture of99Mo-molybdenum oxide and metal oxides on temperaturebetween 500 and 750∘C in an air flow and sim90 of 99mTcis recovered in the same way as applied in the first methodThe third method is the low temperature sublimation Thismethod is based on the heating the solid powders of 99Mo-molybdate of tetravalent metals such as titanium and zirco-nium molybdate on 380ndash450∘C in a water vapour flow and40ndash65 of 99mTc is recovered in the saline in form of ready-to-use Based on this method the portable sublimation 99mTcgenerators were commercially produced in the nineteeneighties and used for years in several hospitals in Hungary[92 94 114 115] The thermochromatographic separation atan oven temperature of 1090∘C has also been successfullyutilized for the recovery of 94mTc from 94MoO

3in the years

1990s [116]This approach is expected to be used for the 99mTcseparation from 99Mo targets From that time until nowno update version of the sublimation-based 99mTc recoverytechnology is found in the literature

43 Electrochemical Methods for 99mTc Recovery In the pastthe electrochemical separation of 99mTc from 99Mo was per-formed for a radioanalytical purpose Recently Chakravartyet al have further developed this method for seeking a 99mTcproduction capability using a low specific activity 99Mo The99mTc electrodeposit and the followed pertechnetate recoverywere performed at the voltage 5V (current 500mA andcurrent density 300mAcm2) and 10V (reversed polarity)respectively Postelectrolysis purification of 99mTc solutionwas also completed with an alumina column [117 118]

44 Column Chromatographic Methods for 99mTc Recoveryand Integrated 99mTc Generator Systems (Column Chro-matography-Based 99mTc Generator Coupled with Postelu-tion PurificationConcentration Process) The 99mTc recovery

technologies used in the separation of 99mTc from low specificactivity 99Mo which are based on the column chromato-graphic method are recognized as the best ways to bring thelow SA 99Mo-based 99mTc generators to the hospital userswithminimal fissionnonfissionModiscrimination Conven-tional chromatographic generators using alumina columnsare not compatible with the loading with low SA 99Mo due toits overwhelming excess of nonradioactive molybdenum Byrule of thumb 1-2 of adsorption capacity of the alumina col-umn loadedwithmolybdenum is tolerated to avoid a harmful99Mo breakthrough in the final 99mTc saline eluate To pro-duce a generator of acceptable activity using low SA 99Mo asignificantly large alumina column is required to be capableto adsorb 1-2 g of Mo target because the capacity of aluminafor Mo adsorption is limited (sim20mgMog of alumina) Alarge alumina column requires large volume of the eluentto elute patient-dose quantities of 99mTc As a consequencelarge eluent volumes cause the radioactive concentration ofthe 99mTc-pertechnetate to become unacceptably low for usein most radiopharmaceutical diagnostic procedures So thepostelution concentration process is required to increase the99mTc-activity concentration Although the recovery of 99mTcfrom enriched molybdenum target material has been appliedinUzbekistan andPOLATOM the 99mTc concentration of theeluate eluted from an enriched 98Mo target-based generator ismoderately improved with the use of high neutron flux reac-tor irradiation [2]

In principle there is no impediment for simple in-lineconcentration of the 99mTc solution obtained from largealumina column generators using simple postelution concen-tration technologies As examples the large alumina column-based 99mTc generators using low specific activity 99Moeluted with chloride (saline) or nonchloride (acetone) eluentand combined with a 99mTc concentration unit were testedThe first low SA (7ndash15GBqg) 99Mo-based 99mTc generatorsystemusing up to 80-gram alumina column (jumbo aluminacolumn generator) was developed in India [52 53] 70mLsaline is used for 99mTc elution from this system and a con-centration process with three consecutive processing steps(99mTc loading onto Dowex-1times8 resin column 99mTc elutionfrom the resin column with 02M NaI solution removingof Iminus ions from the effluent downstream with AgCl column)was applied The second generator system was developed inPakistan using a large alumina (16 g) column and acetoneeluent (nonchloride organic eluent) [51] 99mTc recovery in asmall volume of saline was followed after removing acetonefrom the 99mTc acetone eluate

Despite the high recovery yield and good labelling qualityof the highly concentrated 99mTc solution achieved the timeconsumption for a large volume elution and the complexityin processing at concentration stage make large aluminacolumn-based generator systems as described above incon-vincible for a commercial scale production and for the conve-nient utilization in the hospital environment So the recoveryof 99mTc from the low SA 99Mo still requires further develop-ment to make it useful for nuclear medicine application Asa result of the development performed in many laboratories


3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion

Radiochemicalprocessing

setup

(b)

Purificationassembly

Column 1 Column 2

Watervial

Salinevial

Product

MEK collection vialWaste water

collection vial

(c)

Figure 5 MEK extraction of 99mTc using a tandem sorbent column system for nonevaporation removing of MEK from the extracted 99mTc-MEK phase (a) conceptual process diagram of 99mTc recovery by MEK extraction using a tandem cation-exchange resinacidic aluminacolumn system for nonevaporation removing of MEK (1 cation-exchange resin column 2 alumina column 3 peristaltic pump 4 Miliporefilter 5 redistilled water 6 saline 7 final sterile 99mTc-pertechnetate solution 8 waste container V

1and V

2 solenoid valves S syringe for

MEK addition EX extractor containing 99Mo M magnetic stirrer) The generator design is performed by author of this paper based on theprocesses reported in the literature [98 102] (b) Process diagram and (c) computerizedmodule developed in BRIT for 99mTc separation basedon the MEK extraction coupled with MEK-removing using a tandem basicacidic alumina column system [99 100]

around the world some useful 99mTc recovery technologiesdeveloped up to date are described in the following

It is the fact that the solution of high 99mTc concentrationcannot directly be produced from the low specific activity99Mo source except the 99mTc production based on the sol-vent extraction sublimation and electrochemical methodsmentioned above So the technetium recovery technologybased on the coupling a chromatographic 99mTc-generatorcolumn of high Mo-loading capacity with a postelutionpurificationconcentration processunit should be consid-ered as an important solution This technical solution isperformed by an integrated system so-called RADIGIS(radioisotope generator integrated system) to produce amedically useful 99mTc-pertechnetate solution of sufficiently

high 99mTc-concentration In the following different versionsof RADIGIS developed to date are described

441 Technetium Selective Sorbent Column-Based 99mTcRecovery and Relevant Integrated 99mTc Generator SystemSeveral sorbents have been developed for selective adsorptionof pertechnetate ions from aqueous solutions Some of themsuch as TEVA Spec resin (Aliquat-336 or tricapryl methylammonium chloride extractant impregnated in an inertsubstrate) and activated charcoal adsorb TcO

4

minus ions stronglyin dilute nitric acid solutions However the strong acidicsolution (8M HNO

3) required for recovery of TcO

4

minus ions isnot preferred for practical application on the basis of dailyuse in nuclear medicine [119ndash123] Some sorbents such as


ABEC (aqueous biphasic extraction chromatographic) resinand strong anion-exchange (Dowex-1times8) resin adsorb TcO

4

minus

ions from alkaline or neutral aqueous solutions These resinsare suitable for use in the production of 99mTc-generator byvirtue of the fact that TcO

4

minus ions can be easily desorbed fromthese sorbents by contacting with water or suitable organicsolvent [124 125]

(1) Aqueous Biphasic System-Based 99119898119879119888-PertechnetateRecovery Method [124 126ndash131] A 99mTc selective sorbent(ABEC-2000) column is recently developed to separate99mTc from the alkaline solution of low specific activity 99MoA new generator system developed by NorthStar MedicalRadioisotopes (USA) using low specific activity 99Mo isbased on the ABEC-2000 resin column coupled with analumina guard column This system is shown in Figure 6

The separation process is performed as follows An alka-line 99Mo solution in 5MNaOHobtained fromdissolution ofmolybdenum targets is fed onto theABEC-2000 resin columnwhich is specifically designed to adsorb pertechnetate Oncethe column is loaded it is first washed with 5M NaOH solu-tion to remove any molybdate that also may have beenadsorbed on the column and then by a buffer solution of pH8 Following the wash the technetium is stripped from thecolumn with a normal saline solution which is then passedthrough an alumina guard column to remove the residual99Mo impurities The eluate is then passed through dual 022micron sterility filters to achieve an injectable 99mTc-pertech-netate solutionThe process can be repeated once a day as the99mTc builds up in the 99Mo solution The 99mTc separationefficiencies for several consecutive days of operation weregt90 with no detectable 99Mo breakthrough To date theinherent disadvantage of this generator system reflected fromthe comment of user is that the elution process of this systemtakes a long time (about 40 minutes) and requires a 15-minute procedure for cleaning of column and tubing beforethe next elution is available There is also some process toreplace some components of the generator system that mustbe done after 5 elutions Although the automated operationof this system facilitates the cumbersome elution-cleaning-replacing process its being accepted as a user-friendly devicemay be challenged by the hospital userrsquos community who isquite familiar to the simple operation of the current fission99Mo-based 99mTc generators

The specific volume of 99mTc solution produced by this99mTc recovery system is comparable to that of an aluminacolumn generator loaded with the high SA fission This newgenerator system is currently in the process of being validatedfor nuclear pharmacy use through a NDA on file with the USFood and Drug Administration [2 130 131]

(2) Organic Solvent-Eluted Ion-Exchange Resin Column-Based 99119898119879119888-Pertechnetate Recovery Method The chromato-graphic system of Dowex-1times8 resin column combined withtetrabutyl-ammonium-bromide (TBAB) eluent has beendeveloped for separation of pertechnetate ions from aque-ous 99Mo-molybdate solution Using commercially availableanion-exchange resin Dowex-1times8 (25mg) to selectively trap

and separate 99mTcO4

minus from a low specific activity 99Mo solu-tion and then recovering 99mTcO

4

minus ions from the Dowex-1times8columnby elutionwith TBAB inCH

2Cl

2were reported After

being purified by passing through a neutral alumina columnand washing the resin column with water the aluminacolumn will be flushed with saline to strip Na99mTcO

4 Sub-

sequent quality control revealed no significant levels of tracemetal contaminants or organic components 99mTc recov-ery yields of greater than 90were demonstrated while radi-ochemical purity was consistently over 99 [125]

442 HighMo-Loading Capacity Column-Based 99mTc Recov-ery and Relevant Integrated 99mTc Generator Systems Theassessment on the capable utilisation of the high Mo-loadingcolumns loaded with low specific activity (119899 120574)99Mo for pro-duction of 99mTc-generator is performed based on the 98Mo(119899 120574)99Mo reaction yield (119860Mo-99) and Mo-loading capacityof columnpackingmaterial (119870)The relationship between theneutron flux Φ of the reactor used for the 99Mo productionand the Mo-loading capacity (119870) of the column packingmaterial is derived [69 70 103 132]

Based on the activation equation for the neutron capturereaction 98Mo(119899 120574)99Mo rarr 99mTc the 99Mo activityyield(119860Mo-99) and the relationship between 119860Mo-99 and 119870 arecalculated as follows

119860Mo-99 = 1628 times 10minus13 (Θ times 119866 times 120590act times Φ

119886)

times (1 minus 119890minus0693(119905119879))

119860Mo-99 = 2055 times 10minus14 times 119866 times Φ times (1 minus 119890minus00104times119905)

119866 =119860Mo-99

2055 times 10minus14 times Φ times (1 minus 119890minus00104times119905)

119870 =119866

119898=

119860Mo-992055 times 10minus14 times 119898 times Φ times (1 minus 119890minus00104times119905)

(10)

119870 = 119866119898 is the Mo-loading capacity of the packingmaterial loaded in one generator column 119866(119892) is the weightof molybdenum element target which will be used for theproduction of one generator 119898(119892) is the weight of columnpackingmaterial packed in one generator column119860Mo-99(Ci)is the given 99Mo radioactivity of the generator which isplanned to be produced 119905 is the activation time hour Θ =2375 is the natural abundance of 98Mo 119886 = 9594 is themolecular weight of molybdenum 119879 = 667 hours is the halt-life of 99Mo 120590Act = 051 barn is the normalised thermal andepithermal neutron activation cross-section of 98Mo nuclide

It is assumed that a generator column of the best perfor-mance for pertechnetate elution can be eluted with an eluentof volume 119881(mL) = 2m where 119898 (119892) is the weight of thecolumn packingmaterialThe relationship between the 99mTcconcentration in the eluate (119862Tc) the neutron flux and 119870 isalso set up This relationship shown in Figure 7 is for a givencase of the following conditions The weight of the columnpacking material is 5 g and corresponding elution volume is10mL The activation time of natural Mo target is l00 hours


solution

B

ABEC resin column

was

te

From

DAlumina column

D

Rinse 5 M NaOH solution

Rinse buffer or more dilute NaOH solutionC

From

B C

From

A

Injectable 99m Tc pertechnetate

Strip 99m Tc with water or sterile saline

99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)

Figure 6 99mTc recovery usingABEC resin column (a) process diagram (b) automated radionuclide separatorARSII developed byNorthStarMedical Radioisotopes (USA) using ABEC resin column [2]

50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)

Figure 7 Assessment on the 99mTc-radioactivity (119860Tc) and99mTc-

concentration (119862Tc) of the eluate eluted from the generators of5-gram weight column-packing materials of variable Mo-loadingcapacity 119870 (low specific activity 99Mo solutions used are producedin the nuclear reactors (a) thermal neutron fluxΦ = 21013 nsdotcmminus2 sdotsecminus1 (b) Φ = 51013 n sdot cmminus2 sdot secminus1 (c) Φ = 1014 n sdot cmminus2 sdot secminus1The saline eluate volume is 10mL)

With these conditions the above mentioned 119870-equationis derived as follows

119870(5100)

=172 times 1013

Φtimes 119860Tc (11)

119870(5100)

= 1198665 is the Mo-loading capacity of the packingmaterial used in the generator 119860Tc(mCi) = (0875 times 119860Mo-99)

is the radioactivity of 99mTc in this generator 119862Tc (mCimL)is the radioactive concentration of 99mTc in the eluate elutedfrom the generator

This relationship shows a general assessment on thepotential use of the column packing material of givenMo-loading capacity for the 99mTc-generator productionusing (119899 120574)99Mo produced ex-natural molybdenum As an

example the result assessed by above equations indicatesthat the column packing material of molybdenum loadingcapacity 119870 ge 172mgMog could be used to produce a99mTc generator of approximately 300mCi at the generatorcalibration using a 99Mo source of 500mCi activity (at EOB)produced in a reactor of Φ = 51013 n sdot cmminus2 sdot secminus1 and thusa 99mTc-pertechnetate solution of concentration lt30mCi99mTc mL could be achieved This 99mTc solution could beused for limited numbers of organ imaging procedures dueto its low 99mTc concentration as shown in Table 1 Withthe thermal neutron flux Φ gt 51013 n sdot cmminus2 sdot secminus1available in the majority of the research reactors around theworld it is justified that the column packing material of119870 ge 172mgMog should be developed for the effectiveuse in the process of 99mTc-generator production Severalsorbents such as acidicbasic alumina hydrous zirconiumoxide hydrous titanium oxide manganese dioxide silica gelhydrotalcites inorganic ion-exchange materials (zirconium-salt form of zirconium-phosphate ion exchanger) hydroxya-patite mixed oxide of tetravalent metals and diatomaceousearth have been developedinvestigated over the years [20133ndash141] These sorbents are only used for the production offission-99Mo-based 99mTc-generators but they are unsuitablefor 99mTc-generators loaded with 99Mo of low specific activitydue to their low Mo-adsorption capacity (lt100mgMog)

Presently there are the limitations in the available specificactivity of 99Moproduced fromnuclear facilities 1ndash6CigMo(1ndash4Cig at generator calibration day) of 99Mo produced inthe reactors of high neutron flux (gt 1014 n sdot cmminus2 sdot sminus1) usingboth the natural molybdenum and enriched 98Mo targetsand sim10 Cig Mo of 99Mo produced from the acceleratorsas mentioned above The use of these 99Mo sources and


the recently developed column packing materials of highMo-loading capacity in the process of the 99mTc generatorproduction however remain to be addressed In order toreduce the 99mTc solution volume eluted from a column chro-matographic generator using low SA 99Mo to facilitate thepostelution 99mTc-purificationconcentration process the col-umns of as high as possible Mo-loading capacity must beused Although theMo-loading capacitygt025 gMoper gramof column-packingmaterial is achieved to date the loading ofthis material with 1-2 of its capacity (similar to the loadingregime of the alumina column in the fission 99Mo-basedgenerators) using a low specific 99Mo available today willresult in a generator of unacceptably low activity becausethe (119899 120574)99Mo produced in the majority of high neutron fluxnuclear reactors and in the accelerators has a specific activityof 10000 times lower than that of the fission-based 99MoSo the fully Mo-loaded generator columns should be used[57 59 60 69 70 103ndash109 112 113 132 142ndash154] As anexample the 99mTc generated in a 4-gram weight columnof high Mo-loading capacity (250mgMog) which is fullyloaded with 10 g Mo of low specific 99Mo-activity to producea generator of 1ndash4Ci 99Mo on generator calibration day canbe exhaustively eluted in 10mL saline This 99mTc eluate con-tains a higher 99Mo breakthrough than that required for aninjectable 99mTc solution due to the feature of the fully Mo-loaded generator column as mentioned above This eluateneeds to be purified to remove 99Mo breakthrough contam-inant by passing through a sorbent column such as aluminacolumn of sim2-gram weight Finally an additional volume ofthe saline must be used to recover all 99mTc activity fromthe system As a consequence a low concentration 99mTcsolution of approximately 20mL volume is produced Thisvaluemeans a double of saline volume used in a fission 99Mo-based 99mTc generator column of 4 Ci activity loaded with 2 galumina

In case of the fully Mo-loaded generator columns usedthe Mo affinity to the sorbent should be high enough toensure a minimal Mo-breakthrough into the 99mTc eluateeluted from the generator because the Mo breakthrough isdirectly proportional with the Mo amount loaded on thecolumn and reversely with its affinity to the sorbent (knownas distribution coefficient 119870

119889) To achieve a maximal affinity

for the adsorption process the chemosorption with covalentbonding between molybdate ions and functional groups ofthe sorbent should be expected in the process of sorbentdesign

Asif andMushtaq [155] have tested to highly load aluminacolumn with (119899 120574)99Mo to produce a medically accept-able pertechnetate solution of higher 99mTc concentrationHowever the high 99Mo breakthrough in the 99mTc eluateand the moderate Mo-loading capacity of this fully Mo-loaded alumina column (150mgg) remain inconvincible fora practical application of this technique for the generatorproduction

The efforts of using a fully Mo-loaded column of highMo-loading capacity and high adsorption affinity howeverare not the all to be done in this endeavour in the process

development of 99mTc-generator production because thesolution volume and 99Mo breakthrough of the 99mTc eluateeluted from fully Mo-loaded generator columns loaded withlow specific activity 99Mo are still unacceptably higher com-pared with those obtained from the fission 99Moalumina-based generators All these issues suggest that the highMo-loading capacity column-based 99mTc recovery shouldbe combined with a postelution purificationconcentrationprocess to produce a 99mTc-pertechnetate solution of medi-cally useful radioactive concentration for use in most radio-pharmaceutical diagnostic procedures

With regard to the development of 99mTc generator usinglow SA 99Mo the column packing materials of high Mo-loading capacity developed in several laboratories are clas-sified into two following groups The first group includesthe chemically formed solid powder materials containingmolybdenum in the form of a chemical compounds such aspolymolybdate compounds of tetravalent metals (in the formof solid gels) such as Zr- Ti- Sn-molybdates and so forth[57 59 60 69 70 103ndash106 112 113 132 142ndash147] The secondgroup composes of the sorbents of high Mo-adsorptioncapacity such as the functionalized alumina [156] the poly-meric compounds of zirconium (PZC) titanium (PTC)and so forth [107 108 148ndash154 157] the nanocrystallinemixed oxides of tetravalent metals [62ndash64 109ndash111 118 158]the nanocrystalline zirconiumtitanium-oxide and alumina[159ndash161] and recently multifunctional sorbents [40ndash42 58]Such materials as discussed below are shown to be suitablefor 99mTc generator production All these column-packingmaterials have a significantly higher Mo-loading capacity(gt250mg Mo per gram) than that of the alumina (lsquo10ndash20mgMo per gram)The 99mTc can be separated from these columnpackings by elutionwith a small volume of nonsaline or salineeluents The choice of the eluent is subject to the postelution99mTc-purificationconcentration process preferred for theoptimal design of an integrated system RADIGIS to producethe medically useful pertechnetate solution of sufficientlyhigh 99mTc concentration

The chemistry of molybdate ion sorption on hydrousmetal oxides is a good guide in the process of sorbent devel-opment It is established that there are 4 adsorption sitesgroups on the alumina surface basic OH group (=AlndashOH)neutral OH group (ndashAlndashOHndashAlndash) acidic OH group (ndashAlndashOH[ndashAlndash]

2) and coordinatively unsaturated site (ndashAl3+ndash)

All these sites adsorb the molybdate ions to different extentsdepending on the pH of the solution and type of aluminasorbent used Molybdate reacts irreversibly in a reaction(chemosorption) with the basic OH groups (at pH 85ndash6)However as soon as these are protonated molybdate alsostarts to be reversibly adsorbed by electrostatic interactionThe neutral OH groups when protonated also reversiblyadsorb the molybdate ions Molybdate is strongly adsorbedby the coordinatively unsaturated sites and by acidic OHgroups via a physisorptionelectrostatic interaction at pH lt5For this reason acidic alumina is used for the 99Mo99mTcgenerator production Among tetravalent metal oxides tita-nia and zircona are usually used inmany studies for the 99mTc


0 2 4 6 8 10

Volume of 2 M HCl solution (mL)

0

2

4

6

8

pH o

f mol

ybda

te so

lutio

nVolume of 2 M NaOH solution (mL)

MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4

Figure 8 pH titration curves of molybdate solutions [57]

recovery from 99Mo Titania and possibly nanocrystallinetetragonal zircona (calcined at 600∘C IEP at the pH 45 [62156 161]) contain mainly coordinatively unsaturated sites sothese sorbents may adsorb molybdate ions via a physisorp-tionelectrostatic interaction at pH lt5 However hydroustitanium oxide and zirconium oxide sorbents contain manyacidic and basic OH groups respectively Consequentlymolybdate ions are adsorbed on the hydrous titanium oxidesurface by a physisorption mechanism at pH lt4 with a lessadsorption affinity compared with that of hydrous zirconiumoxide which adsorbs molybdate by an irreversible chemicalreactionchemosorptionMolybdate ions adsorb on themetaloxides in different forms depending on the pH of the solutionbecause the molybdate polymerizes in weakly acidic solutionas follows

7MoO4

2minus + 8H+ larrrarr Mo7O24

6minus + 4H2O (12)

On the polymerization the polymerized molybdatemolecules have variable molecular weights depending on thepH This property can be experienced from the results ofthe potentiometric titration of molybdate solutions shownin Figure 8 As shown the molybdate is in the form ofpolymolybdate Mo

7O24

6minus at pH lt5 [57]When the titanium- and zirconium-molybdate gels are

used as column packing materials in the 99Mo99mTc gener-ator preparation the molybdate covalently bonds with Ti4+andor Zr4+ ions in the way of nonstoichiometry So theresidual charges of the polymolybdate ionswill be neutralizedby the positive charge of the protons and the gels willbehave as a cation exchanger Le (1987ndash1994) has found thepolyfunctional cation-exchange property of the titanium-andzirconium-molybdate gels [59 69 104] He has taken thisadvantage of the molybdate gels to design the water- andorganic solvent (acetone)-eluted gel-type 99mTc generatorsas shown in Figures 14 17 and 18 [57 59 60 69 103ndash106 146] The molybdate gels have two functional groupsin their structure and the total ion-exchange capacity ofapproximately 10meqg was found as shown in Figure 9 The99mTcO

4

minus anions as the counter ions of the cation-exchange

0 2 4 6 8 10 12 14meq NaOH per gram sorbent

pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel

Figure 9 pH titration curves of molybdate gel sorbents [57 59 6069]

gel matrix can be easily eluted with the water and water-soluble organic solvent from the column of gel-type 99mTcgenerator Sarkar et al (2004) also developed a water-elutedzirconium-molybdate gel-based 99mTc generator [49]

The cation exchange property can be found in all thesorbents which are fully loaded with molybdate ions So theelution of 99mTc with water or with acetone (as nonsaline elu-ents) from the generator column fully loaded with 99Mo willprovide the advantages for a consecutive postelution purifi-cationconcentration process Le (2011) has developed anautomated system of the radioisotope generator coupled withpurificationconcentration process using PTCPZC sorbentcolumns and an eluent composed of water containing smallamount of NaCl (0005) This system called RADIGIS-99mTc is shown in Figure 16 [62ndash64 109 109ndash111 158]

The 99mTcO4

minus anions are hardly eluted from a partly Mo-loaded sorbent column with nonsaline eluents due to itsstrong adsorption on the unoccupied residual OH groupsof the sorbent However this elution can be achieved if thecolumn is wetted with a sufficient amount of residual salineThis phenomenon has been experienced in the case of the99mTc elution with acetone from an alumina column [51] Inthis case the water in the aqueous saline phase existing on thesorbent surface plays a role of an ion transporter for 99mTcO

4

minus

and Clminus ions

(1) Saline-Eluted Generator Systems Using High Mo-LoadingCapacity Columns and Integrated Generator Systems

(i) Saline-Eluted Molybdate-Gel Column-Based 99119898119879119888-Generator Systems A zirconium-molybdate (ZrMo) and tita-nium-molybdate (TiMo) gels are the generator column pack-ing materials used exclusively with low specific activity 99Mofor 99mTc recovery The molybdate gel column is consideredas a fully Mo-loaded sorbent column as well These mate-rials were first developed by Evans et al [143] andEvans and Mattews [162] and then further improvedby several research groups around the world in the 1980s


[49 57 59 60 69 70 103ndash106 132 146 147] A comprehensivedescription of molybdate gel-based 99mTc generator systemsusing low specific activity 99Mo is presented in IAEA-TECDOC-852 [70] ZrMo and TiMo gels are preparedin the form of water insoluble solid powders containingmolybdenum under a strictly controlled synthesis conditionto ensure the best performance when used as a columnpacking material in chromatographic 99mTc generators Theconditions under which amolybdate (zirconiumor titanium)is prepared will influence the nanostructure of the gels andthus the 99mTc generatorrsquos performance Different 99mTcelution performances were found with the gels of amorphousor crystallinesemicrystalline structure [57 59 69 132] Asa rule of thumb the 99Mo breakthrough from the generatorcolumn and the 99mTc elution yield are higher with the amor-phous gels while the performance of the crystalline structuregels reverses The porosity of the solid gel particles is alsoan important factor influencing the out-diffusion of thepertechnetate ions and thus the 99mTc elution profile and99mTc-elution yield of the generator column So the gelsynthesis conditions such as the molar ratios of zirconium(or titanium) to molybdenum the solution concentrationsthe order of reactive agent addition the reaction temperaturethe gel aging conditions (time and temperature) the acidityof reaction mixture the drying conditions of the gel product(time temperature and atmosphere) and so forth must beproperly controlled in order to consistently reproduce theproperties of the gel

The 99mTc-elution performance of the gels is assessedbased on the following important factors the 99mTc elutionefficiency the 99Mobreakthrough in the99mTc eluatemechan-ical stability and the uniformitysize of the gel particles andthe capability of thermal (steam) autoclaving

The dried gel contains about 25 by weight of molybde-num (025 g Mo per gram of gel) and has the characteristicsof a cation exchanger as discussed above The passage of anaqueous eluent (typically either water or normal saline)through a molybdate-gel column releases the 99mTc How-ever an additional small column of alumina is required toremove 99Mo-impurities from the 99mTc eluate

As in the case of the alumina-based 99mTc generator sys-tem the radiochemical purity of the 99mTc eluted from amolybdate gel-type generator can be impacted by the effectsof radiation changes in temperature or pH and the pres-ence of reducingoxidizing agents Finished product qualitycontrol testing clearly demonstrates that the radiochemicalpurity is equivalent to that of the traditional alumina col-umnfission 99Mo-based 99mTc generator

TiMo and ZrMo gels are prepared in two different formsthe post-irradiation synthesized 99Mo-containing molybdategel and the preformed nonradioactiveMo-containingmolyb-date gel In contrast to postirradiation gels which is chemi-cally synthesized from the 99Mosolution of neutron-activatedMo target the preformed gel target is synthesized undernonradioactive conditions and the gel powders are loadedinto the generator column after being activated with neutronin the reactor to perform 98Mo(119899 120574)99Mo reaction However

the disadvantage of the preformed gel is that this gel powdermaterial requires a thoughtful neutron irradiation conditionto avoid any adverse effects on the change of gel structure andchemical properties which is caused by high temperature andextremely high radiation dose during reactor irradiation Inconsequence the 99mTc elution performance of the neutron-activated gels will be degraded So a special design of theirradiation container and specific radical scavenger have beenused to save the original properties of the pre-formed gelduring its long time irradiation in the reactor [69 70 104132] A great care should be taken during the synthesis ofTiMo gel to avoid any contaminants which may generatethe radionuclidic impurities during neutron activation of theTiMo gel targets [163]

Originally the molybdate gel-column-based generators(Figure 10) are specifically designed to use low specificactivity 99Mo to provide the 99mTc solution for diagnosticimaging the limited numbers of the organs due to low activityconcentration of 99mTc solution eluted from these generatorsTypical elution profiles of the molybdate-gel column-based99mTc-generator are presented in Figure 11 The technicalmaturity of this chromatographic gel-based 99mTc recoverysystem has advanced significantly in the last decades

(ii) Saline-Eluted High Mo-Loading Capacity SorbentColumn-Based 99119898119879119888 Generator Systems

(a) Polymeric Zirconium Compound and Polymeric Tita-nium Compound Sorbents Polymeric zirconium-oxychlorideor polymeric zirconium compound (PZC) and polymerictitanium-oxychloride or polymeric titanium compound(PTC) sorbent materials were first developed for use in(119899 120574)99Mo-based 99mTc generators These titaniumzirconi-um-based inorganic polymers exhibit both excellent 99Mo-adsorption capacity and 99mTc-elutionThemain constituentsof this sorbent material are zirconium oxygen and chorineThe adsorption capacity of PZC and PTC for 99Mo wasreported to be much higher than that of the conventionalalumina Many research activities were performed in JAEA(Japan) in NRI (Vietnam) and in other countries in Asiaon the use of PTC andor PZC materials as high Mo-loading capacity sorbent materials for packing of variousradionuclide-generator columns [62ndash64 107ndash111 148ndash154158] The PTCPZC sorbent of high Mo-adsorption capacityserves as a 99Mo-loaded column fromwhich the 99mTc can beeluted in patient-dose quantities In contrast to a traditionalalumina of low Mo-adsorption capacity currently used ina commercial chromatographic generator system loadedwith high specific activity 99Mo solution the high adsorp-tion capacity of PTC and PZC sorbent for 99Mo (270ndash275mgMog) is useful in reducing the size of the generatorcolumn and thus the daughter nuclide eluate volume whenthese columns are used for low specific radioactivity 99Mo-based generator production

PZC and PTC sorbents were synthesized from isopropylalcohol (iPrOH) and the relevant anhydrousmetallic chlorideunder strictly controlled reaction conditions A given amount


Lead shielding

TiMo or ZrMo gel

eluateValueIsotonic saline

MF

99m Tc pertechnetate

Clean-up column

(a) (b)

Figure 10 Typical chromatographic gel-type 99mTc generators (dual column systems compose of a ZrMo (99Mo) gel column coupled with apurification acidic-alumina column) (a) Gelutec-A 99mTc-generator manufactured by NRI (Vietnam) (b) Geltech 99mTc-generator by BRIT(India) (Note no 99mTc-concentration is available in these generator systems In Gelutec-A system two alumina columns are installed inparallel and a selectorvalve is inserted between them to direct the 99mTc eluate from the gel column being passed over each column for 5consecutive purificationelutions) [2 57 59 60 103]

Eluate volume (mL)

09 NaCl

7 g Pre-TiMo(99Mo-99mTc)

15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3

Figure 11 99mTc elution profiles of Gelutec-A generator A the gen-erator column without coupling with alumina purification columnB the generator column coupled with alumina purification column[57 59 60 103ndash106]

of relevant anhydrous metallic chloride (ZrCl4for PZC or

TiCl4for PTC) was carefully added to different amounts of

iPrOHThe temperature of the reactionmixture immediatelyreached 96ndash98∘C for the iPrOH-ZrCl

4mixture and 92ndash94∘C

for iPrOH-TiCl4The temperature of solutionwasmaintained

at these values and stirred gently by magnetic stirrer inopen air until the solution became viscous As the reactiontemperature increased a water-soluble PZC or PTC gel (theintermediate precursors) was formed at 129ndash131∘C for PZCand at 111ndash113∘C for PTC sorbent The water-insoluble solidPZC or PTC materials of particle size of 010mm to 001mmwere split out by keeping the reaction temperature at 141-142∘C (30 minutes) for PZC and at 124ndash126∘C (45 minutes)for PTC These were the finished products of PZC and PTCsorbentsThe characterizations of the PZC andPTCmaterialssynthesized and their preparation conditions are summarisedin the literature [62 107ndash109 149ndash154]

The molecular formula of PZC sorbent was also esti-mated The actual molecular weight (organic residueincluded) was determined to be 119872 = 59013 where 119883 is theorganic molecules in one PZC molecule which was equiv-alent to 963 of PZC molecular weight as seen at thermalanalysis Because the organic substance in this formulawas attributed to a residual organic by-product of chemicalsynthesis reaction and was completely being released frompolymer matrix in aqueous solution the segment unitof real polymer compound is of the following formulaZr

15(OH)

30Cl

30(ZrO

2)sdot126H

2O The steric arrangement of

atoms in this molecule is shown as Scheme 1Themolecular weight of PZC sorbent is 533302 Chlorine

content is 563 millimol Cl per gram PZC sorbent Ionexchange capacity is 563meq per gram PZC sorbentThe ionexchange capacity derived from the above chemical formulaoffers an adsorption capacity of 2700mgMog PZC or


H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19

Ti Ti Ti Ti Ti Ti Ti Ti Ti Ti Ti Ti Ti

H H H

HHHHH

O O O O O O OO OO O O O O O

O

O

ClClCl Cl

ClCl OO OOOOOOOOOOO ClCl

H

middot middot middot

Scheme 2

5171mg Wg PZC by assuming molybdate or tungstate ionsadsorbed on PZC in the form of MoO

4

2minus or WO4

2minus respec-tively In addition it is assumed that one molarity of MoO

4

2minus

orWO4

2minus ion consumes 2 equivalents of ion-exchange capac-ity of PZC and PTC sorbents (one equivalent of MoO

4

2minus ionis 48 g molybdenum and one equivalent of WO

4

2minus ion is91925 g) This type of strong adsorption suggests a covalentbond between molybdate or tungstate ions and zirconiummetal atom

The segment unit of real polymer compound is of the fol-lowing formula Ti

40Cl

80(OH)

80(TiO

2)97

sdot 60H2OThe steric

arrangement of atoms in this molecule is shown as Scheme 2The molecular weight of PTC sorbent is 1493956 The

chlorine content of PTC sorbent is 535 millimolgram PTCsorbent (18965 of chlorine element in one gram PTC)This is equivalent to the ion exchange capacity of 535meqgPTC sorbent and consequently offers very high adsorptioncapacities of 2570mgMog PTC or 4918mgWg PTC byassuming molybdate or tungstate ions adsorbed on PTCin the form of MoO

4

2minus or WO4

2minus respectively and onemolarity of MoO

4

2minus or WO4

2minus ion consuming 2 equivalentsof ion-exchange capacity of PTC sorbent This type of strongadsorption gives a covalent bond between molybdate ortungstate ions and titanium metal atom The theoreticalvalues of adsorption capacity calculated from the molecularformula of PZC and PTC compounds detailed above arein good agreement with the practical values achieved atthe potential titration and at the Mo andor W adsorptionexperiments The adsorption capacity of both sorbents wasvariable depending on the temperature reaction time andgel aging process before forming the solid PZC and PTCpolymers The actual molybdenum adsorption of PZC and

PTC sorbents which is to some extent higher than the abovementioned values accounted for the noncovalently adsorbedmolybdate ions andor for adsorption of small amounts ofpoly-molybdate ions These polyanions could form at thebeginning stage of adsorption in the strongly acidic solutionwhich resulted from the hydrolysis of ndashZrndashCl (orndashTindashCl)groups of the back-bone of PZC or PTC molecules

The PZC sorbents in its original forms which are devel-oped in Japan and Vietnam contain so much HCl contentin their structure and are subject to hydrolysis in an aqueoussolution resulting a strong acidity So the ldquoin-potrdquo adsorptionprocess should be applied to load 99Mo-molybdate onto thesorbent before packing it into the generator column Thisprocess is performed automatically using a smart machine(Figure 12(a)) developed by Japan Atomic Energy Agency(JAEA) and Kaken Co Ltd (Japan)

The PZCPTC sorbents modified by further physico-chemical treatments performed in ANSTO and NRI whichare used for different radionuclide generator developmentsare used for packing the generator column so-called theprepacked column This prepacked PZCPTC column isthen loaded with 99Mo-molybdate solution to produce the99Mo99mTc generators in the same manner as that used forthe production of the traditional alumina-based 99mTc gener-ators (Figure 12(b)) Although the 99Mo-adsorption capacityof the modifiedprepacked PZCPTC sorbent column is tosome extent lower than that of original form of PZC sorbentthe former is preferred due to an easy-to-load property of thenonradioactive column loading procedure [108]

The saline-eluted highMo-adsorption capacity PZCPTCcolumn (fully Mo-loaded column)-based 99mTc generatorsystems have been developed and the pertechnetate eluates of


(a)

(b)

Figure 12 Loading of 99Mo solution on the PZCPTC sorbentsfor 99mTc-generator production (a) automatic machine developedby Kaken Co Ltd (Japan) for the in-pot 99Mo-adsorption onPZC sorbent followed by packing of 99Mo-loaded PZC into thegenerator column in the process of PZC sorbent-based 99mTc-generator production [107] (b) the 99mTc-generators installed withprepacked PZCPTC sorbent columns are in-line loaded with lowspecific activity 99Mo solution in the process of PZCPTC-based99mTc-generator production at NRI [108]

99mTc concentration suitable for a limited numbers of SPECTimaging procedures were obtainedThe design of this type ofthe generator is similar to the molybdate gel-type generatordescribed in Figure 10

(b) Nanocrystalline Sorbents Le (2009) has recently devel-oped a group of nanocrystalline tetravalent metal oxide andmixed oxide sorbents for the radionuclide generator technol-ogy and radiochemical separation development [62ndash64 109ndash111] The tetravalent metal is each selected from the groupconsisting of Zr Ti Sn and GeThe chemical composition ofthe sorbents are described as Zr

119909M119910O119911(OH)

(2119909+2119910minus119911) where

119909 and 119910 value pairs (119909 119910) are (10 00) (075 025) (05 05)and (00 10) and the value 119911 is variable depending on heatingof the powder so as to form the sorbent at the last step ofsynthesis process Each M is independently Ti Sn or GeThe process for making the sorbent comprises several stepsreacting a metal halide or a mixture of metal halides and analcohol to form a gel and heating the gel to activate the con-densation andor polymerisation reaction for the formationof a particulate material This solid polymer gel material inpowder form with particle sizes from 010 to 001mm is thenleft to cool at room temperature overnight before startingfurther chemical treatment The solid polymer gel powder istreated in an alkali solution which contains oxidizing agentNaOCl about 10mL 05M NaOH solution containing 1

by weight NaOCl is used per gram of solid polymer gelpowder The solid powderoxidant solution mixture is gentlyshaken using a mechanical shaker for at least 4 h so as toconvert the gel structure solid powder into a macroporoussolid powder and to convert any lower-valence metallic ionsto their original 4+ valence The volume of solution requiredper gram of solid gel powder is determined so that the pHof solution at the process end is between 2 and 5 The solidmatter is then separated by filtering through a sintered glassfilter washed several times with double-distilled water toremove all dissolved sodium and chloride ions and driedat 80∘C for 3 h to dryness to obtain a white solid powderThe resulting white solid powder is calcined at a temperaturein the range from 500∘C to 700∘C for a time of about 3 h(the actual temperature depending on the particular sorbentbeing prepared) (the actual temperature depending on theparticular sorbent being prepared) The calcinations are tocomplete the crystallizationrecrystalization of the nanopar-ticles so as to form the sorbent At the end of this heatingprocess the resulting powder is sieved In particular thefraction of particle size between about 50 and about 100 120583mmay be collected to be used as a sorbent for chromatographiccolumn packing applied to chemical separation processesThe initially formed solid is commonly in the form of whitesolid powder particles composed of different clusters ofgreater than about 100 nm in size The clusters are aggregatesof amorphous and semicrystalline nanoparticles (less thanabout 5 nm) The clusters appear to be held together by weakhydrogen bonds and van derWaals bonds Consequently theaggregate particles are macroporous and soft During high-temperature calcining the amorphous and semicrystallinenanoparticles (less than about 5 nm) crystallize to form crys-talline nanoparticles inside clusters Simultaneously thesecrystalline nanoparticles partially melt and combine withother nanoparticles inside the same cluster with interfacialcoordinatively bondordered structure to form larger porouscrystalline particles Because there is longer distance betweenthe clusters than that between nanoparticles within a singlecluster the nanoparticles belonging to different clusters donot combine with each other to form a single mass Adjacentnanoparticles on the surface of clusters fuse into a limitedarea of the cluster surface to form a bridge to crosslink theclusters (at this stage the clusters have already become largercrystalline particles) to form sorbent particles In this waymesomacroporosity formed between the former clustersmay be maintained The partial fusion and surface coor-dinative connection are thought to cross-link the particlesto create a hard porous matrix of solid material The highchemical andmechanical stability of the product is thought toresult at least in part from the formation of stable crystallinemonophase in the solid material The crystalline structure ofthe product is stable when exposed to high radiation dosesfrom radioactive materials The powders obtained using theabove process have high stability and high porosity (averagepore size sim120 A) and may be used as a state-of-the-art sor-bent for different chemical separation processes for examplefor the separation of highly radioactive materialsThe dopingby different amounts of metal ions (eg Ti Sn or Ge) addedto zirconium chloride solution in the synthesis is thought to


(a) (b)

(c) (d)

(e) (f)

Figure 13 SEMpicture of the nanocrystalline sorbents used for packing radionuclide generator columns Sorbents (a) ZiSorb (b) TiSorb (c)SnSorb (d) ZT-11 (e) ZT-31 and (f) organic-polymer resin OASIS-HLB (Waters) of average pore diameter 80 A (for a comparison purpose)[62]

be responsible for a stabilized crystalline phase which makesthe product chemically and mechanically stable The dopingof smaller ions Ge4+(radius 053 A) Ti4+(radius 0605 A)and Sn4+(radius 069 A) onto the matrix of larger ionsZr4+(radius 080 A) facilitates isomorphism-based adsorp-tion of the parent nuclides such as 68Ge4+ 113Sn4+ and44Ti4+ ions from its acidic solution for the preparationof the 68Ge68Ga 113Sn 113mIn 110Sn 110mIn and 44Ti44Scgenerators respectively Moreover the doping process isalso to increase the numbers of covalently unsaturated sites(= Mminus+) and to reduce the isoelectric point (IEP) ofzircona (at pH sim8) to a value (at pH sim4ndash6) which aresuitable to the adsorption of parent nuclide ions and to theelution of daughter isotope in the process of 99Mo99mTc

and 188W188Re generator production The Mo-adsorptioncapacity of these sorbents is in the range 200ndash240mgMogand saline-eluted 99mTc-pertechnetate recovery is satisfiedwithmedical use requirement Scanning electronmicroscopy(SEM) images showing the micro- and mesoporosity ofthe sorbent materials synthesized above are presented inFigure 13 X-ray diffraction patterns of these sorbents showeda monophase of the nanocrystalline structure [62 64]

The nanocrystalline zircona (tetragonal phase t-ZrO2)

nanocrystalline titania andnanocrystalline alumina sorbentsof high Mo-adsorption capacity were also developed inBhabha Atomic Reasearch Center Mumbai (India) for usein the 99mTc generator production [160 161 164 165] Thesorbents were synthesized by controlled hydrolysis of 017M


zirconium chloride solution in a well stirred 25M ammoniasolution at pH 9ndash11 The formed hydrogel was washed withdeionized water until free of chloride ions Subsequently thehydrogel was then refluxed at 96∘C for 24 h in an ammoniasolution of pH 12 and then filtered washed with waterdried at 100∘C overnight calcined at 600∘C for 5 h andground and sieved to get particles of 50ndash100 mesh forchromatographic column packing The specific area of thesematerials (100ndash340m2g) is in the range of that reported foralumina (150m2g)These sorbents have highMo-adsorptioncapacity and good 99mTc elution properties The static 99Mo-adsorption capacity gt250mg Mo per gram sorbent wasreported The breakthrough capacity was 100mgg The col-umn loaded with 25 of its total static Mo-adsorptioncapacity was investigated on the 99mTc elution performanceThe 99mTc elution yield of gt90 was achieved with salineeluent The 99mTc elution performance of fully Mo-loadednanocrystalline sorbent columns was not tested The longtime of 50min is needed to attain the adsorption equilibriumof molybdate and tungstate ions in the static adsorptionprocess The kinetics of 99Mo-adsorption process is ratherslow using these materials probably because their pore sizeis smaller than the size of the molybdatetungstate ions (poresize of sim04 nm for the sorbent compared with the ion sizeof 0646 nm for MoO

4

2minus and 0648 nm for WO4

2minus) This factmay reduce the practical application of this sorbent due tohigh potential of particle cracking when it is highly loadedwith MoW The utilisation of these sorbents for loading oflow specific activity 99Mo in the process of the production of99mTc188Re generators needs more experimental investiga-tions for improvement in the porosity and dynamic loadingcapacity Continuing the developments of nanomaterial-based sorbents for 99mTc and 188Re-generator production theabove mentioned scientist group also reported the capabilityof mesoporous nanocrystalline alumina in the productionof 99mTc188Re generators [164 165] Although the Mo-adsorption capacity (230mgg) is in the similar range asthat achieved by the above-mentioned sorbents (PZCPTCsorbents and nanocrystalline zircona) the effort was madeto use this new alumina in a tandem system of doublecolumns for 99mTc-generator preparation Despite the use ofdouble columns for increasing the Mo-loading capacity ofthe generator this configuration requires the (119899 120574)99Mo ofimproved specific activity produced in a high neutron flux(1014-1015 n sdotcm2 sdot sminus1) to produce a clinical scale 99Mo99mTcgenerator

(c) Functionalized Sorbents Functional alumina sorbents(sulfated alumina and alumina sulphated zircona) developedin Korea [156] have a 99Mo-adsorption capacity gt200mgMoper gram of sorbent The sorbents were synthesized by thereaction of aluminium-tri-sec butoxide zirconium-prop-oxide and anhydrous H

2SO

4in mixture of HCl and alkyl

alcohol The obtained precipitate was dried at 100∘C toget the final sorbent product This sorbent material wasused for the 99mTc generator production The 99mTc-pertechnetate was eluted by saline with 60ndash85 elution yield

The multifunctional sorbents were also developed by MED-ISOTEC (Australia) for the 99mTc generator productionand for several radiochemical separations including the usesin 99Mo99mTc and 188W188Re generator production [58]These sorbent materials may comprise porous silica havinga plurality of groups of formula -O

4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the

surface thereof wherein each M is independently Ti Zr HfSn Th Pb Si or Ge each A is independently either OHor R (where R is an alkyl group C

119899H2119899+1

and 119899 is from 1 to 18)each R

10158401015840

is an aminoalkyl group [(CH2)119898-(Amino group1)]

where 119898 is from 1 to 6 each X is a [M1015840(oxo-hydroxyl-alkyl-aminoalkyl)M10158401015840(oxo-hydroxyl-alkyl-aminoalkyl)] group offormula[(OM1015840)j(OH)

119886(C

119887H2119887+1

)119888[(CH

2)119889-(Aminogroup2)]

119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901

[(CH2)119902-(Amino group3)]

V]

where each M1015840 is independently Si Ti Zr or Hf and each11987210158401015840 is independently Si Ti Zr or Hf 119911 is from 1 to 3 119894 isfrom 0 to 3 (119894 + 119896) is from 0 to 3 119895 is 0 or 1 119886 is from 0to 3 119887 is from 1 to 6 119888 is from 0 to 3 119889 is from 1 to 6 119890 isfrom 0 to 3 (119886 + 119888 + 119890) is 3 119891 is 0 or 1 119892 is from 0 to 3 ℎis from 1 to 6 119901 is from 0 to 3 119902 is from 1 to 6 V is from 0to 3 and (119892 + 119901 + V) is 3 The 99Mo-adsorption capacity ofthese materials (gt600mgMog) is significantly higher thanthat of the sorbents developed up to date The kinetics of99Mo-adsorption process is fast with these materials due totheir high porosity (pore size 2ndash10 nm) and high surface area(gt700m2g) The excellent 99mTc elution properties of thesesorbents are well confirmed when used with saline eluentThe functional sorbent generator columns can be sterilizedby a normal steam process in the autoclave A commercialproduction of the 99mTc generators using these sorbents forloading of low specific activity 99Mo is well promising

(2) Nonsaline Eluent-Eluted Generator Systems Using HighMo-Loading Capacity Columns and Integrated Generator Sys-tems In contrast to the saline-eluted generator systems usinghigh Mo-loading capacity columns which are used for alimited number of SPECT imaging procedures due to arather low 99mTc concentration of 99mTc eluate obtained thenonsaline aqueous solution-eluted 99mTc generators or 99mTcrecovery processes are mainly developed to couple withthe 99mTc-purificationconcentration process to set up the99Mo99mTc generator systems which are suitable for a rou-tine production of 99mTc solution ofmedically useful radioac-tivity concentration effectively used in all the diagnosticSPECT imaging procedures

(i) Nonsaline Aqueous Solution-Eluted 99119898119879119888 Generator Sys-tems Using Molybdate-Gel Columns Recent advances inradiopharmaceutical diagnostic applications using the 99mTc-pertechnetate of moderate to high activity concentration (asshown in Table 1) require the development of the integratedgenerator system RADIGIS which composes of a molybdate-gel column-based 99mTc generator coupled with a postelution99mTc concentrator to produce a medically useful pertechne-tate solution of sufficiently high 99mTc concentration

A version of RADIGIS developed in the 1980s is presentedin Figure 14 The operation of this system is semiautomated


3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)

Figure 14 Integrated 99mTc-generator system (RADIGIS) (a) process diagram and design (b) photo of GELUTEC-C system used for years inVietnam which composes of a ZrMo (99Mo) gel column coupled with a zirconaalumina column-based purificationconcentration unit 1 gelcolumn 2 zirconaalumina column 3 peristaltic pump 4 selector valve 5 circulating eluent container (water containing 0005 NaCl) 6saline vial 7 final 99mTc solution 8 Milipore filter 9 coarse filter (Specifications Semi-automated operation based on the circulating elutionwith an eluent of redistilled water containing 0005 NaCl Processing time 20min Final 99mTc solution of 100ndash200 mCimL concentrationdepending on the activity of 99Mo-loading) [57 103]

0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)

Figure 15 99mTc elution profiles of the system GELUTEC-C (ZrMo(99Mo) gel column coupled with a metal-oxide sorbent column-basedpurificationconcentration unit) (a) the elution profile of the generator columnof 50 gweight of titanium-molybdate gel elutedwith redistilledwater (b) the elution profiles of the concentration columns of 15 g weight eluted with saline A alumina B zisorb C titania D MnO

2[57]

This integrated generator system has been used for yearsin the hospitals in Vietnam [57 59 60 103] The low-costautomation of the generator elution using a simple electronictime-sequence-based control unit provides the conveniencein operation and preference for use in a daily hospital envi-ronment The 99mTc elution profile of the molybdate gel-column-based generator is shown in Figure 15 TiMo andZrMo gel columns are prepared as described in the previ-ous section ldquoSaline-eluted molybdate-gel column Both thepost-irradiation synthesized gel and preformed gel columnsare equally used for the preparation of nonsaline aqueoussolution-eluted 99mTc generator systems Redistilled water is

used as eluent for both TiMo and ZrMo gel columns whilethe water containing 0005 NaCl is more effectively usedfor ZrMo gel column [57 59 60 69 70 103ndash106 132 146]Similarly the zirconium-molybdate gel-based 99mTc genera-tor which is eluted with water is developed in India [49]

(ii) Nonsaline Aqueous Solution-Eluted 99119898119879119888 GeneratorSystems Using High Mo-Loading Capacity Sorbent Columns

(a) PZCPTC Sorbent Column-Based Generators Research isin progress atMEDISOTEC (Australia) on the use of the highMo-adsorption capacity PTCPZC sorbent materials for the


pertechnetate solution

Lowactivityliquidwaste

From step B

From A andPCM

Purificationconcentration module(PCM)

A

Eluent for generator elution(water containing 0005 NaCl)

adsorption (fully Mo-loaded generatorcolumn)

BSterile saline eluent

Injectable 99m Tc

PZCPTC sorbent column for 99 Mo

(a) (b)

Figure 16 Integrated radioisotope generator system (radionuclide generator column coupled with an automated purificationconcentrationunit of the programmable time sequence control) (a) process diagram (b) photo of the system recently developed at MEDISOTEC andANSTO [58 62ndash64 109ndash111]

production of a nonsaline aqueous solution-eluted 99mTc gen-erator systemThese sorbents are prepared as described in theprevious section ldquoSaline-eluted high Mo-adsorption capacitysorbent columnsrdquo The PTC and PZC sorbent columns areloaded with a low specific activity 99Mo solution and the99mTc-pertechnetate eluted with redistilled water containing0005 NaCl is consecutively concentrated using a smallalumina concentration column

The automated purificationconcentration unit coupledwith 99mTc generator column is shown in Figure 16 Thisdevice is a versatile radionuclide generator system which canbe used for the production of different daughter nuclide solu-tions (such as 99mTc 188Re 90Y and 68Ga) of high activityconcentration using low specific radioactivity parent nuclides[63] The chemical process applied in this system is based onthe selective adsorption of 99mTc which is eluted from alarge 99Mo-PZCPTC column onto a significantly smallerconcentration column In the following step the technetiumis stripped from the columnwith a small volume of injectablesaline solution Optionally this small sorbent column iswashed to remove any parent nuclide ions andmetallic impu-rities that also may have been adsorbed on the columnFollowing the wash the daughter nuclide is stripped from thecolumn with a small volume of solution suitable for injectionor for investigational purposes

The process of the daughter radionuclide elution fromthe generator followed by the postelution purificationcon-centration process was performed using a low-cost auto-mated bench-top system [62ndash64] This system was designedbased on the timing sequence of several processing stepswithout feedback control The variable flow rate of eluents

used for elutionpurification in this system also ensures theoptimisation of operating times with respect to differentadsorptiondesorption kinetics of daughter radionuclide ionspecies which is controlled by the sorbents used in thegenerator and the purification columns

(b) Alumina Column-Based Generator Systems Severalresearch groups reported on using different nonsaline aque-ous eluents for elution of 99mTc from alumina-based gen-erator systems which couple with a concentration unit forincreasing the pertechnetate concentration of the 99mTc solu-tionThe eluents used are the following the mixture of 07Macetic acid and 00225M NaCl solution [50] the solution ofthe salt of weak acids such as ammonium acetate citratetitrate and so forth and the mixture of acetic acid andammonium acetate solution [43ndash48] Although the elutionperformance of these eluents is excellent and suitable for theconcentration processes using an anion exchange materialssuch as QMA Sep-Pak Cartridge NH

2Amberlite BondElut

SAX Dowex-1 DEAE Cellulose and so forth the largevolume of the eluents used for the 99mTc elution from largealumina column-based generators is the main issue for theroutine use of all these methodsThe details of 99mTc concen-tration techniques will be reviewed in the next sections

(c) New Sorbent-Based Generator Systems No work on usingnonsaline aqueous eluents for the elution of 99mTc fromrecently developed high Mo-adsorption capacity sorbentmaterials (such as nanocrystalline zircona (tetragonal phaset-ZrO

2) nanocrystalline titania nanocrystalline alumina


TiMo bed weight (g)0 2 4 6 8 10

10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR

Figure 17 Retention volume 119881119877versus TiMo-column-bed weight

(TiMo particle size 100ndash200 mesh column size 10mm id) aacetone as eluent b 09 NaCl solution as eluent [59 106]

and functional alumina sorbents (sulfated alumina andalumina sulphated zircona)) was performed until now Theintegrated 99mTc-generator systems (integration of elutionpurification concentration and column-generation) using acolumn containing multifunctional sorbent materials of highMo-adsorption capacity and an acetate solution as circulatingeluent are recently developed by MEDISOTEC [58]

(iii) Nonsaline Organic Solvent-Eluted 99119898119879119888 Generator Sys-tems Using Molybdate-Gel Columns and Acetone Eluent(Solid-Liquid Extraction 99119898119879119888 Generator) 99mTc can beeluted from a zirconiumtitanium-molybdate gel-type gener-ator column and from 99Mo-loaded diatomaceous earth sor-bent using organic solvents (so-called ldquosolid-solventrdquo extrac-tion) [57 59 60 103ndash106 141 146] The results of inves-tigations on the elution of 99mTc from TiMo and ZrMo-gel columns using organic solvents such as methyl ethylketone (MEK) acetone ethyl ether chloroform and so forthshowed that the separation yield of 99mTc was around 80for acetone eluent and lt40 for the othersThe 99mTc elutionprofile of the acetone elution is very similar to that of salineeluent (Figure 17) So the acetone can be used as a usefuleluent for a solid-solvent extraction-based generator usingzirconiumtitanium-molybdate- gel columns of high Mo-loading capacity

The solid-liquid extraction-based 99mTc generator systemusing acetone as eluent operates as follows First the 99Mo-molybdate gel (TiMo or ZrMo) columns are prepared asdescribed in the previous section ldquoSaline-eluted molybdategel columnsrdquoThen the 99mTc is eluted with acetone eluent Inthe following steps the 99mTc-acetone eluate is evaporated todryness and the recovery of 99mTc pertechnetate into a smallvolume of saline is followed The 99mTc pertechnetate is thenpassed through a small alumina and Millipore filter givinga sterile pertechnetate solution of high 99mTc concentrationThe generator flowchart is shown in Figure 18

Acetone is a less toxic volatile solvent Low boiling tem-perature and low risk of polymerization of the acetone offersthe advantages of economical low temperature evaporation

1

2

3

4 5

6

F

G

F

V1

V2

V3

Figure 18 Process diagram of the solid-liquid extraction-based99mTc-generator system GELUTEC-B developed in NRI 1 99Mo-loaded molybdate-gel column 2 acetone evaporator 3 air pump4 acetone reservoircondenser 5 saline for recovery of 99mTc-pertechnetate 6 99mTc-pertechnetate injectable solution 119881

1ndash3valves G alumina guard column MF Millipore filter [57 59 60103 105 106]

of 99mTc acetone eluate of small volume which is performedfaster using a less elaborated apparatus as compared withMEK extraction-based 99mTc generator system describedabove Thus the generator system based on solid-solventextraction using acetone as eluent is found to meet therequirements of an effective method of 99mTc recovery fromlow specific activity 99Mo The quality of pertechnetate solu-tion obtained from this generator system was found to meetall the requirements of 99mTc pertechnetate injection asspecified in various pharmacopeia [36 37]

99mTc elution from an alumina column-based generatorusing acetone eluent was also tested and reported with apositive result [51]

(iv) Nonsaline Organic Solvent-Eluted 99119898119879119888 Generator Sys-tems Using High Mo-Loading Capacity Sorbent Columns Nowork on using organic eluent for 99mTc elution from therecently developed sorbent materials of high Mo-adsorptioncapacity (such as nanocrystalline zircona t-ZrO

2 nanocrys-

talline titania nanocrystalline alumina and functional alu-mina sorbents (sulfated alumina and alumina sulphatedzircona) polyfunctional sorbents) was performed until now

443 99mTc Concentration Methods Used in the 99mTcRecovery from Low Specific Activity 99Mo

(1) Characterization and Performance Assessment of Chro-matographic Column Concentration Process Le (2003) hasdeveloped a method for assessment of concentration factor


values which are achievable in different concentrating pro-cesses This method rely on the basic parameters currentlyused in the chromatographic processes such as the retentiontimevolume and the distribution coefficient of the solute[103] This evaluation is an important guide for designingof the concentrator with optimal operation conditions Inhis further development as being reported in this review astandardization method of concentration factor evaluation isdeveloped using a standard elution which is performed withnormal saline solution (09 NaCl) as a reference In thiscase the normal saline may play both the role of a generatoreluate containing solute (99mTc) which is fedloaded ontothe concentration column to be concentrated and the roleof the eluate of final concentrated 99mTc-product which isstripped from the concentration column This approach isuseful for the researchers in the process of concentrationmethod development to evaluate the effectiveness of oneconcentration system (sorbent-eluent system) in comparisonwith others which could or would be performed under thesimilar (normalized) conditions of the experiments

In general the performance of the concentration processis characterized with the concentration factor 119899

119899 =1198882

1198881

(13)

For a concentration process of solute recovery yield (119896) thefollowing mass balance is established

1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)

Relating the above equations the following is derived

119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881

2are the solution volumes before and after

concentration respectively 1198881is the solute concentration in

the solution before the concentration and 1198882is the solute con-

centration in the solution after the concentration using agiven concentration process

In individual case of 99mTc concentration 1198881is the 99mTc

radioactivity concentration in the eluate eluted from the99mTc generator and 119888

2is the 99mTc radioactivity concentra-

tion in the 99mTc solution concentrated using a given concen-tration process

Except being concentrated by the evaporation of solventor by the electrolysis all the chromatographic column con-centration processes are described by the following basicequations

For a sorbent (eg ion-exchange resin) characterizedwith a volume of solid substrate used in the concentrationcolumn

1198811

= 119881119898

+ 119870119881

times 119881119878 (16)

For a sorbent (eg alumina) characterized with a specificsurface area of solid substrate used in the concentrationcolumn

1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)

(more details about these equations for refer to [166])The following is received by relating (16) and (17)

119870119881

times 119881119878

= 119870119878

times 119878 (19)

119870119878value is calculated by putting the value of119870

119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870

119882(mLg)are the area

volume and weight distribution coefficient of the solute(99mTcO

4

minus) in a given sorbent-solution system respectively119878 is the surface area of the sorbent (m2) 119881

119904is the volume of

the dry resin (mL) 119898119888is the weight of the dry resinsorbent

loaded in the column (g) 119878 is the specific surface area of thesorbent (m2g) 119881

119878is the specific volume of the resin (mLg)

120588Re is the weight density of the resin (gmL)Based on the above equations (assuming the dead volume

of the concentration column 119881119898

≪ 1198812) the concentration

factor (119899) is assessed for the designing of the concentratorcolumn as follows

For the ion-exchange resin column

119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)

For the sorbent column

119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)

If 1198812is given as a designed value the concentration factor (119899)

only depends on the value of 119896 119870119878 and 119878 (or 119870

119881and 119881

119878)

As an example the design of the generator systems whichare composed of the molybdate gel (Figure 14) or PZCPTCnanocrystalline sorbent (Figure 16) generator column cou-pled with a alumina concentrator column described abovewas based on the following parameters calculated using theabove equations 119870

119878= 20 119881

2= 50mL and 119896 = 095 the

available concentration factor for a bolus elution (with 1198811

=460mL for a generator TiMo (or PZCPTC)-column of 375ndash380 g weight 119881

2= 75mL and 119896 = 1) is 119899 = 557 the elution-

by-elution (with 1198811

= 65mL for each elution from a 53 gweight-sorbent column Mo-breakthrough of lt40 120583gmL1198812

= 50mL and 119896 = 095) concentration factor is 119899 = 112The design is also performed with a conservation of the influ-ence of MoO

4

2minus breakthrough in the primary solution eluted


from the generator columnThe above-described calculationmethod was also successfully applied for the evaluation anddesigning of a compact concentrator ULTRALUTE using amore effective new sorbent concentration-column as shownin Figure 3

Due to the diversity of the eluents of variable volume usedfor the elution of 99mTc-generators the evaluation of concen-tration factor of the integrated generator systems (integratedelution-concentration processes) should be harmonizedusing a common language for communicationjustificationon the elutionconcentration performance of the given sys-tems When a nonsaline solvent-eluted process is applied forthe 99mTc generator elution and consecutively the eluate ofthis elution is concentrated using a chromatographic columnconcentration method we need a tool to assessjustify theeffectiveness of each elution-concentration process in com-parison with others So we need a reference to be used for thecomparisonThe saline-eluted process of the 99mTc generatoris considered as a gold standardreference elution due to itssuitability for clinical use The reference is set up as follows

119881Eqv (equivalent volume) is the volume of nonsalineeluent used for the elution of 99mTc from a generator (with anonspecified activity) giving a 99mTc elution yield 119891

119864which is

equal to the yield achieved by an elution performed with thevolume 119881

1198781of saline

119881119864is the volume of nonsaline eluent (containing 99mTc)

actually passed through the concentration column of theweight119898 in which the 99mTc will be retained with adsorptionyield (119909) from its total amount present in the volume 119881

119864

At the stage of the elution of the concentration columnwith a small volume of saline 119881

1198782is the volume of the saline

used to recover the 99mTc from the concentration column toachieve a concentrated 99mTc solution and the elution yieldof this concentration column is 119910 The yield of the overallconcentration process 119896 is composed of the adsorption yield119909 and recovery elution yield 119910 as follows

119896 = 119909 times 119910 (23)

The normalized concentration factor will be set up as follows

119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)

With introduction of the weight of the sorbent (119898) used inthe concentration column the further analysis of the aboveequation is shown as follows

119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)

where 119881(mLg) is the specific elution volume of the concen-tration column eluted with saline to get a concentrated 99mTcsolution of volume 119881

2119878

Equation (26) composes four components characterizingthe system involved

The term (1198811198781

119881Eqv) characterizes the relation of thesaline elution versus alternative nonsaline elution of a givengenerator column

The term (1119881) characterizes the saline elution of theconcentrator column

(119881119864

119898) and 119870 characterize the adsorptionelution capa-bility of the sorbent for the pertechnetate ions with an alter-native nonsaline eluent

The equations described above can be used for both thetheoretical and practical evaluations of the normalized con-centration factor

119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)

Equation (27) is used for theoretical assessment of the nor-malized concentration factor where 119896

119879= 1 119881

119864minus119879and 119881

1198782minus119879

are obtained from the practical determination of retentiontimeretention volume using an established standard chro-matographic procedure performed with the same column orare calculated from the distribution coefficient119870 as describedabove 119870

119882is determined as described in the literature [166]

119899119879value is used for the evaluation of the effectiveness of the

concentration system (sorbent-eluent)method of interestwhile 119899

119875value is to evaluate the performance of a practical

procedureconcentrator device designed using this concen-tration systemmethod 119899

119875value is calculated as follows

119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881

1198782minus119875are the volume of nonsaline eluent and

saline actually used in the concentration proceduredevicerespectively

Note that the overall 99mTc recovery yield of the integratedgenerator-concentration system will be

119884 = 119891119864

times 119896 (29)

where 119891119864is the elution yield of the generator column and 119896 is

the purificationconcentration yieldTable 3 shows the majority of the concentration methods

developed up to date and the normalized concentrationfactor values assessed by the approach described above usingthe process performance parameters extracted from theliteratures It may be interesting to note that inmany cases theoptimal design of a practical procedureconcentrator devicewas not performed to match the inherent effectiveness of themethod developed

(2) Chemistry and Methods of 99119898119879119888 Concentration Thechemistry of pertechnetate ions should be reviewed hereinin regard to the development of the 99mTc concentrationmethods Except for the materials containing cyclic com-pounds of 120587-electrons almost all the anion-exchange mate-rials reversibly adsorb the pertechnetate ions in aqueoussolutions Unfortunately the chloride ions compete stronglywith pertechnetate ions in the adsorption on these sorbentsThis fact makes the concentration of 99mTc-pertechnetatefroma saline solution very hardThe following parameters areuseful to justify a proper selection of the sorbent and suitableeluent to develop an effective process for 99mTc concentration


Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio

n-basedconcentrationmetho

dsaren

otinclu

dedherein)

Metho

dandconcentrationcolumn

(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro

mconcentrationcolumn

Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460

65lowastlowastlowast

7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources

lowastlowastlowastVa

lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column


Table 4 Details of the methods of 99mTc-pertechnetate concentration from the saline eluate of 99mTc-pertechnetate (dual columnconcentration methods)

Scheme Concentration process 99mTc-generatorcolumn References

Elution Interfering ionsremover

99mTc concentrator

1A Step A salineStep B saline

Cation exchange resin(Ag form)

Alumina zircona andMnO2 columns Alumina Ruddock (1978) [38]



OnGuard-AGBondElut-SAX column Alumina Blower (1993) [39]



OnGuard-AGQMA-SepPak column Alumina Knapp et al (1998)

[43 44]



Functional sorbent(isosorb-FS-01)

columnsAlumina Le and Le (2013) [58]



MnO2 TiO2 ZrO2ZT-11 ZT-31 sorbent

columnsAlumina Le et al (2013) [40]

2A Step A salineStep B NaI solution AgCl powder column Anion exchange resin

(Dowex-1 times 8) column Large alumina Chattopadhyay et al(2002) [53]

3A

Step A salineStep B

Tetrabutylammoniumbromide in methylene

chloride

Not needed

Anion exchange resin(Dowex-1 times 8) columncombined with solvent

evaporator

Large aluminaChattopadhyay and

Das (2008)[52]

Injectable

pertechnetatesolution

A Saline eluent

Generator column

Sterile saline eluent

Saltchlorideremoving column


From B From A

Concentration column

B

Injectable


A Saline eluent

Generator column

Iodide eluent

Iodide removing column


From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A

General scheme 1A General scheme 2A General scheme 3A

99m Tc 99m Tc99m Tc

Figure 19 Group 1 of concentration methods 99mTc-pertechnetate concentration from the saline eluate of the 99mTc generator

Technetium has an electron configuration with presenceof d-orbital electrons (K L M 4s2 4p6 4d5 5s2) while that ofchlorine is (K L 3s2 3p5) and oxygen K 2s2 2p4 The energyof outer electrons of these atoms is in the range of 2poxygensim 3pchlorine sim 4dtechnetium lt 5stechnetium The ion radiusof TcO

4

minus is 32 A while that of Clminus ion is 181 A This bigdifference in the ion radius justifies a strong competition of

chloride in the adsorption with pertechnetate ions when theanion exchange resin is applied for TcO

4

minusClminus separationIn the aqueous solutions pertehnic acid (HTcO

4) has an

ionization constant 119901119870119886

= 03 So the weak acid of 119901119870119886

gt 03

should be used as eluent in the process of 99mTc pertechnetateelution from the generatorconcentration system The weakacid usedmust also have a119901119870

119886value below that of the sorbent


Injectable


ANonsaline aqueous eluent

Generator column



From C From A B

Concentrationeluentremoving column

C BWater rinse

(waterwater + small amountof NaCl)acetate solutions)

Water rinse


A

Generator column

Saline eluentConcentration column (alumina )


From C

Cation-exchange resin column forremoving competitive non-chloride ions

B

From A B

C

Nonsaline aqueous eluent

Injectable


A Nonsaline organic solvent

Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv

entConcentration solvent

evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C

Concentrationalumina column

B

(sodium nitrate solution)

C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis

Concentrationelectrochemical cell

B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B

General scheme 2B General scheme 3B


99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc

Figure 20 Group 2 of concentration methods 99mTc-pertechnetate concentration from nonsaline eluate of the 99mTc generator


Table 5 Details of methods of 99mTc-pertechnetate concentration from the nonsaline eluate of 99mTc-pertechnetate (single and dual columnconcentration methods)

Scheme Concentration process Generator column ReferencesElution 99mTc concentrator

1B A H2OB saline

Alumina andor TiO2MnO2zircona

TiMoZrM molybdate gel Le (1990) [57]

1B A H2OB saline Alumina ZrMo molybdate gel Sarkar et al (2004) [49]

1BA NH4OAc + NH4NO3

B waterC saline

QMA SepPak Alumina Knapp et al (1998)[43ndash45]

1BA acetic acid + NaCl

B waterC saline

QMA SepPak AluminaMushtaq (2004) [50]Le (2013) (for this

review)

1B

A acetic acid +ammonium-acetate

B waterC saline

DEAE-cellulose Alumina Sarkar et al (2001)[47 48]


B waterC saline

DEAE-cellulose Alumina Le (2013)(for this review)


B waterC saline

DEAE-sephadex Alumina Le (2013)(for this review)


B waterC saline

Isosorb-FS-01 Alumina Le and Le (2013)[58]

2BA Na2SO4B H2OC saline

Pb-resin-alumina Alumina Bokhari et al(2007)[54]

3B Step A acetoneStep C saline Evaporator TiMoZrMo gel Le (1987ndash1994)

[57 59 60 104]

3B Step A acetoneStep C saline Evaporator Alumina Mushtaq (2003)

[51]

4BA NaNO3

B NaNO3 + SnCl2C saline

Redox agent + alumina Alumina Seifert et al (1994)[55]

5BA H2OB H2OC saline

Electrochemical cell with Ptelectrodes ZrMo molybdate gel Chakravarty et al (2012)

[56]

used in a consequent pertechnetate-concentration process toensure the reversible adsorption of TcO

4

minus ions in a sorbentcolumn of reasonably small volume

The conflict exists between the conventionalconvenientuse of saline in the elution of medical isotope generator andthe challenge of chloride ions in the process of 99mTc concen-tration So the 99mTc concentrationmethods developed up todate in different laboratories are dedicated to the 99mTc con-centration from the saline eluate or from nonsaline eluateof the generators Accordingly they are classified in twofollowing groups and described as follows

(i) Group 1 99119898119879119888-Pertechnetate Concentration from theSaline Eluate of the 99119898119879119888 Generato 119903 In the first groupof concentration methods are briefly described in Table 4

The general process diagrams are shown in Figure 19The main characteristic of this group is the increase of99119898119879119888-pertechnetate concentration from a saline elutate of the99119898119879119888 generator As an example in one of the dual columnpurificationconcentration processes (Scheme 1 in Figure 19)the saline eluate of the generator is first passed through asmall silver ions loaded sorbent (or an ion exchange resin inAg+ form) column which traps the chloride anions allowingsubsequent in-tandem passage through a sorbent cartridge(concentration column) with specific trapping of the TcO

4

minus

ionsThe pertechnetate anion is subsequently easily removedwith a small volume of normal saline ready for ldquokitrdquo radiola-belingThe concentration factors can be as high as 10ndash60withthe silver ion stoichiometry based on the volume of the salineeluant Among concentrator prototypes developed using this


postelution concentration concept the commercially avail-able concentrator device ULTRALUTE is shown in Figure 3[40ndash42]

(ii) Group 2 99119898119879119888-Pertechnetate Concentration from theNonsaline Elution of the 99119898119879119888 Generator In the second groupof concentration methods are briefly described in Table 5The general process diagrams are shown in Figure 20 Themain characteristic of this group is the increase of 99119898119879119888-pertechnetate concentration from a nonsaline elutate of the99119898119879119888 generator These methods are generally known as thesingle column concentration methods developed in years1980s for the purificationconcentration of the dilute solutionof 99mTc which is eluted from the low specific activity(119899 120574)99Mo column generator [57 59 60] Recently manyalternatives have been further developed and improved withan automated operation as shown in Figures 5 14 and 16This process is based on the selective adsorption of 99mTceluted from the 99Mo column onto a significantly smallersorbent column (concentration column) In the followingstep the technetium is stripped from the column with asmall volume of injectable saline solution Optionally thissmall sorbent column can be washed to remove any parentnuclide ions and metallic impurities that may also have beenadsorbed onto the column Following the wash the daughternuclide is stripped from the column with a small volumeof solution suitable for injection or for other investiga-tional purposes The automated purificationconcentrationunit coupled radionuclide generator shown in Figure 16 is aversatile systemwhich can be used for production of differentdaughter nuclides (such as 99mTc 188Re 90Y and 68Ga) givingsolutions of high radioactive concentration from low specificradioactivity parent nuclides

5 Summary

99mTc plays an important role in diagnostic nuclear medicineimaging Demographic and medical trends suggested that inthe near future the global demand for 99mTc will grow at anaverage rate between 3 and 8 per year as newmarkets Sothere is a need for diversity in all aspects of the 99mTc pro-duction using different specific activity 99Mo sources to pro-vide important supplements for increasing reliability of 99Mo99mTc generator supply Accordingly 99mTc recovery shouldbe performed by suitable technologies to make them acceptable for nuclear medicine uses Several alternativesupple-mentary technologies for producing high and low specificactivity 99Mosolutions and for 99mTc recovery therefromhavebeen developed and proposed Some of them are not yetcommercially proven or still require further developmentTo provide the researchersproducers a look into up-to-date 99Mo99mTc technologies a review on the 99Mo sourcesavailable today and on the 99mTc generators developed up todate for increasing the effectiveness of 99Mo utilization isperformed in the format of detailed description of the featuresand technical performance of the technological groups of the

99Mo production and 99mTc recovery Presently the tech-nologies of 99mTc recovery from low specific activity 99Moare playing an increasing role in ensuring the security ofsupplies of 99mTc to users worldwide Various 99mTc recoveryprocesses using low specific activity 99Mohave been reportedBesides the low specific volume of 99mTc eluate obtained theproblem of complexity in operation of 99mTc-generator andof the high cost for automationcomputerization of 99mTc-recovery process remain to be solved regarding cheaperbetter safer and faster supply of 99mTc solution for SPECTimaging use in a daily hospital environment Definitely eachtechnology developed may have some limitation Howeverthe indispensable criteria of 99mTc production technologywhich reflect the acceptance of the hospital users are the reli-abilityreproducibility the simplicity and safety in operationand the proven capability to provide the 99mTc-pertechnetatesolution which is safe for human use and effective for a widerange of the 99mTc-labeled radiopharmaceutical preparationsIn terms of compliance with the requirements of human usethe technologies developed should not contain any materialsof high toxicity for human use which will make the reg-istration process complicated and thus the delay in the tech-nological product delivery

Conflict of Interests

The author declares no conflict of interests

Acknowledgments

The author would like to thank MEDISOTEC and Cyclo-pharm Ltd (Australia) for financial support for the Radionu-clide Development Project which includes the activity of thispaperThe author also acknowledges Professor NabilMorcosMs Hien Do and Minh Khoi Le for their valuable supports

References

[1] P Richards W D Tucker and S C Srivastava ldquoTechnetium-99m an historical perspectiverdquo International Journal of AppliedRadiation and Isotopes vol 33 no 10 pp 793ndash799 1982

[2] Non-HEU Production Technologies for Molybdenum-99 andTechnetium-99m IAEA Nuclear Energy Series no NF-T-54International Atomic Energy Agency Vienna Austria 2013

[3] Expert Review Panel on Medical Isotope Production Report ofthe Expert Review Panel onMedical Isotope ProductionMinistryof Natural Resources of Canada Ottawa Canada 2009

[4] National Research Council of the National Academies Medi-cal Isotope Production without Highly Enriched Uranium TheNational Academies Press 2009

[5] OECDNuclear Energy AgencyThe Supply of Medical Radioiso-topes Review of Potential Molybdenum-99Technetium-99mProduction Technologies OECD Paris France 2010

[6] IAEA-TECDOC-1065 Production Technologies for Molybde-num-99 and Technetium-99m International Atomic EnergyAgency Vienna Austria 1999


[7] IAEA TECDOC-515 ldquoFissionmolybdenum for medical userdquo inProceedings of the Technical Committee Meeting InternationalAtomic Energy Agency Karlsruhe Germany October 1987

[8] A A Sameh and H J Ache ldquoProduction techniques of fissionmolybdenum-99rdquo Radiochimica Acta vol 41 pp 65ndash72 1987

[9] H Arino H H Kramer J J McGovern and A K ThorntonldquoProduction of high purity fission product molybdenum-99rdquoUS patent no 3799883 March 1974

[10] D Novotny and G Wagner ldquoProcedure of small scale pro-duction of Mo-99 on the basis of irradiated natural uraniumtargetrdquo in Proceedings of the IAEAConsultancyMeeting on SmallScale Production of Fission Mo-99 for Use in Tc-99m GeneratorsVienna Austria July 2003

[11] A A Sameh and A Bertram-Berg ldquoHEU and LEU as targetmaterials for the production of fission molybdenumrdquo in Pro-ceedings of the International Meeting on Reduced Enrichmentfor Research and Test Reactors pp 313ndash333 RERTR RoskildeDenmark 1992 TM19 Conf-9209266

[12] T N van derWalt and P P Coetzee ldquoThe isolation of 99Mo fromfissionmaterial for use in the 99Mo 99mTc generator formedicaluserdquo Radiochimica Acta vol 92 no 4ndash6 pp 251ndash257 2004

[13] A Perkins A Hilson and J Hall ldquoGlobal shortage of medicalisotopes threatens nuclear medicine servicesrdquoThe British Med-ical Journal vol 337 article a1577 2008

[14] N Ramamoorthy ldquoCommentary supplies of molybdenum-99mdashneed for sustainable strategies and enhanced internationalcooperationrdquoNuclearMedicine Communications vol 30 no 12pp 899ndash905 2009

[15] R O Marquersquos P R Cristini H Fernandez and D MarzialeldquoOperation of the installation for fission Mo-99 production inArgentinardquo IAEA-TECDOC 515 1989

[16] P R Cristini H J Cols R Bavaro M Bronca R Centuriorsquonand D Cestan ldquoProduction of molybdenum-99 from lowenriched uranium targetsrdquo in Proceedings of the InternationalMeeting on Reduced Enrichment for Research and Test ReactorBariloche Argentina November 2002

[17] ANSTOMedia Releases ldquoANSTO to help supply the world withnuclear medicinerdquo httpwwwanstogovauAboutANSTONewsACSTEST 039937

[18] IAEA TECDOC-1601 Homogeneous Aqueous Solution NuclearReactors for the Production of Mo-99 and Other Short LivedRadioisotopes International Atomic Energy Agency ViennaAustria 2008

[19] A J Ziegler D C Stepinski J F Krebs S D Chemerisov AJ Bakel and G F Vandegrift ldquoMo-99 recovery from aqueous-homogeneous-reactor fuel- behavior of termoxid sorbentsrdquo inProceedings of the International RERTR Meeting WashingtonDC USA October 2008

[20] D C Stepinski A V Gelis P Gentner A J Bakel and GV Vandegrift ldquoEvaluation of radisorb isosorb (Thermoxid)and PZC as potential sorbents for separation of 99Mo froma homogenous-reactor fuel solutionrdquo IAEA-TECDOC-1601September 2009

[21] S Khamyanov and S Voloshin ldquoA proposed internationalproject of low-enriched uranium salt solution reactor for med-ical isotope productionrdquo in Proceedings of the InternationalMeeting on Reduced Enrichment for Research and Test ReactorsLisbon Portugal October 2010

[22] F Stichelbaut and Y Jongen ldquo99Mo production by proton-induced fission with LEUrdquo in Proceedings of the CNS Workshopon the Production of Medical Radionuclides Ottawa Canada2009

[23] F Y Tsang ldquoTechniques for on-demand production of medicalisotopes such asMo-99Tc-99m and radioactive iodine isotopesincluding I-131rdquoWorld Intellectual PropertyOrganizationWO2011093938 A2 August 2011

[24] S Lapi T Ruth and J DrsquoAuria ldquoThe MoRe Project an alter-native route to the production of high specific activity 99Mordquoin Proceedings of the International Symposium on TechnetiumandOther Radiometals in Chemistry andMedicine Brixen Italy2010

[25] A Fong T I Meyer and K ZalaMakingMedical Isotopes FinalReport of the Task Force on Alternatives for Medical-Isotope Pro-duction TRIUMF Vancouver Canada 2008

[26] V S Le ldquoAutomated modular fission Mo-99 productionprocessrdquo Project Proposal ANSTO Life Sciences AustralianNuclear Science and Technology Organisation 2010

[27] V S Le and C D Nguyen ldquoSeparation of Tungsten from LEUfission-produced 99Mo solution to improve technological per-formance in both the processes of 99Mo and 99mTc generatorproductionrdquo in Proceedings of the 5th Asia-Pacific Symposiumon Radiochemistry p 197 Kanazawa Japan September 2013

[28] V S Le ldquoSpecific radioactivity of neutron induced radioiso-topes assessment methods and application for medically useful177Lu production as a caserdquoMolecules vol 16 no 1 pp 818ndash8462011

[29] WCEckelmanldquoUnparalleled contribution of technetium-99mtomedicine over 5 decadesrdquo JACC Cardiovascular Imaging vol2 no 3 pp 364ndash368 2009

[30] P Gould ldquoMedical isotopes time to secure suppliesrdquo TheLancet Oncology vol 9 no 11 p 1027 2008

[31] Technetium-99m Radiopharmaceuticals Manufacture of KitsIAEA Technical Report Series no 466 International AtomicEnergy Agency Vienna Austria 2008

[32] W C Eckelman and B M Coursey ldquoTechnetium-99 m genera-tors chemistry and preparation of radio-pharmaceuticalsrdquoTheInternational Journal of Applied Radiation and Isotopes vol 33pp 793ndash950 1982

[33] J J M de Goeij ldquoRoutes for supply of technetium-99m fordiagnostic nuclear medicinerdquo Transactions of the AmericanNuclear Society vol 77 p 519 1997

[34] K Bremer ldquoLarge-scale production and distribution of Tc-99m generators for medical userdquo Radiochimica Acta vol 41 pp73ndash81 1987

[35] V J Molinski ldquoA review of 99mTc generator technologyrdquoInternational Journal of Applied Radiation and Isotopes vol 33no 10 pp 811ndash819 1982

[36] United States Pharmacopeial ConventionOfficial MonographsUSP 28 Sodium Pertechnetate Tc99119898 Injection United StatesPharmacopiea (USP) 28- National Formulary (NF) 23 2005

[37] British Pharmacopoeia Commission British PharmacopoeiaThe StationeryOfficeNorwichUK 2008 httpwwwpharma-copoeiaorguk

[38] C F Ruddock ldquoPurification of Technetium-99m pertechnetatesolutionrdquo US patent no 4123497 October 1978

[39] P J Blower ldquoExtending the life of a 99mTc generator a simpleand convenient method for concentrating generator eluate forclinical userdquo Nuclear Medicine Communications vol 14 no 11pp 995ndash997 1993

[40] V S Le J McBrayer and N Morcos ldquoA radioisotope con-centrator device for use with a radioisotope source a systemand a process for capturing at least one radioisotope from aradioisotope solution obtained from a radioisotope sourcerdquoAustralia patent application AU2012904683 October 2012


[41] V S Le N Morcos J McBrayer Z Bogulski C Buttigieg andG Phillips ldquoDisposable cartridge-based radioisotope concen-trator device for increasing 99mTc and 188Re concentration ofcommercial radionuclide generator eluatesrdquo Journal of LabelledCompounds and Radiopharmaceuticals vol 56 supplement 1 pS190 2013

[42] V S Le and N Morcos ldquoAn in-line cartridge-based radioiso-tope concentrator device for use with multiple elutions from99mTc and 188Re generatorsrdquo Journal of Nuclear Medicine vol54 supplement 2 p 609 2013

[43] F F Knapp Jr A L Beets S Mirzadeh and S Gluhlke ldquoUseof a new tandem cationanion exchange system with clinical-scale generators provides high specific volume solutionsof technetium-99m and rhenium-188rdquo IAEA-TECDOC-10291998

[44] F F Knapp ldquoThe development and use of radionuclide gener-ators in nuclear medicine recent advances and future perspec-tivesrdquo inModern Trends in Radiopharmaceuticals for Diagnosisand Therapy IAEA-TECDOC-1029 pp 485ndash495 InternationalAtomic Energy Agency Vienna Austria 1998

[45] F F Knapp Jr A L Beets SMirzadeh and SGuhlke ldquoConcen-tration of perrhenate and pertechnetate solutionsrdquo US patentno 5729821 March 1998

[46] S Mirzadeh F F Knapp Jr and E D Collins ldquoA tandemradioisotope generator system for preparation of highly concen-trated solutions of Tc-99m from low specific activity Mo-99rdquoUS patent no 5774782 June 1998

[47] S K Sarkar G Arjun P Saraswathy and N RamamoorthyldquoPost-elution concentration of 99mTcOminus

4by a single anion

exchanger column I feasibility of extending the useful life ofcolumn chromatographic 99mTc generatorrdquo Applied Radiationand Isotopes vol 55 no 4 pp 561ndash567 2001

[48] S K Sarkar G Arjun P Saraswathy and N RamamoorthyldquoPost-elution concentration of (TcOminus

4)- 99mTc by a single anion

exchanger column II Preparation and evaluation of jumbo alu-mina column chromatographic generator for 99mTcrdquo NuclearMedicine Communications vol 22 pp 389ndash397 2001

[49] S K Sarkar P Saraswathy G Arjun and N RamamoorthyldquoHigh radioactive concentration of 99mTc from a zirconium[99Mo]molybdate gel generator using an acidic alumina columnfor purification and concentrationrdquo Nuclear Medicine Commu-nications vol 25 no 6 pp 609ndash614 2004

[50] A Mushtaq ldquoConcentration of 99mTcOminus

4 188ReOminus

4by a single

compact anion exchange cartridgerdquoNuclear Medicine Commu-nications vol 25 no 9 pp 957ndash962 2004

[51] A Mushtaq ldquoPreparation of high specific-volume solutionsof technetium-99m and rhenium-188rdquo Applied Radiation andIsotopes vol 58 no 3 pp 309ndash314 2003

[52] S Chattopadhyay and M K Das ldquoA novel technique for theeffective concentration of 99mTc from a large alumina columnloaded with low specific-activity (n120574)-produced 99MordquoAppliedRadiation and Isotopes vol 66 no 10 pp 1295ndash1299 2008

[53] S Chattopadhyay M K Das S K Sarkar P Saraswathy and NRamamoorthy ldquoA novel 99mTc delivery system using (n120574)99Moadsorbed on a large alumina column in tandem with Dowex-1and AgCl columnsrdquo Applied Radiation and Isotopes vol 57 no1 pp 7ndash16 2002

[54] T H Bokhari A Mushtaq and I U Khan ldquoLead (Pb) columnfor concentration of 99mTc-pertechnetaterdquo Radiochimica Actavol 95 no 11 pp 663ndash667 2007

[55] S Seifert G Wagner and A Eckardt ldquoHighly concentrated[ 99mTc]pertechnetate solutions from (n120574)99Mo 99mTc genera-tors for nuclear medical userdquo Applied Radiation and Isotopesvol 45 no 5 pp 577ndash579 1994

[56] R Chakravarty S K Sarkar M Venkatesh and A Dash ldquoAnelectrochemical procedure to concentrate 99mTc availed from azirconium [99Mo] molybdate gel generatorrdquo Applied Radiationand Isotopes vol 70 no 2 pp 375ndash379 2012

[57] V S Le ldquoPreparation of gel type chromatographic 99mTc gen-erators using Titanium and Zirconium Molybdate columnscontaining (n120574)Mo-99rdquo in Proceedings of the IAEA ResearchCoordination Meeting Bombay India March 1990

[58] V S Le and M K Le ldquoMultifunctional sorbent materials anduses thereofrdquo Australia patent application AU2013903629September 2013

[59] V S Le ldquoProduction of 99mTc isotope from chromatographicgenerator using zirconium-molybdate and titanium-molybdatetargets as column packingmaterialsrdquo in Proceedings of the IAEAResearch Coordination Meeting Bandung Indonesia October1987

[60] V S Le ldquoThe radioisotope and radiopharmaceutical productionin Vietnamrdquo in Proceedings of the 2nd Asian Symposium onResearch Reactors (ASRR rsquo89) vol 2 pp 1ndash19 Jakarta IndonesiaMay 1989

[61] V S Le N Morcos J McBrayer et al ldquoDevelopment of the in-line multiple elution cartridge -based radioisotope concentra-tor device for increasing 99mTc and 188Re concentration of com-mercial radionuclide generator eluates and effectiveness of 99Moutilisationrdquo in Proceedings of the 5th Asia-Pacific Symposiumon Radiochemistry (APSORC rsquo13) Kanazawa Japan September2013 abstract ID 23-RPP-01

[62] V S Le ldquoSorbent materialrdquo US patent application publica-tion US 20130048568 A1 February 2013 World IntellectualProperty Organization WO 2011106847 A1 September 2011Australia patent application AU2010900902 March 2010

[63] V S Le ldquoGallium-68 purificationrdquo US patent application pub-lication US 20130055855 A1 March 2013 World IntellectualProperty Organization WO 2011106846 A1 September 2011Australia patent application AU2010900900 March 2010

[64] V S Le ldquoGallium-68 generator integrated system elution-purification-concentration integrationrdquo in TheranosticsGallium-68 and Other Radionuclides Recent Results in CancerResearch 194 R P Baum and F Rosch Eds pp 43ndash75 SpringerBerlin Germany 2013

[65] V S Le ldquoIdentifying optimal conditions for the production ofnext generation radiopharmaceutiucalsrdquo in Research Selectionspp 71ndash73 ANSTO 2011 httpapoanstogovaudspacehandle102383886

[66] T Genka ldquoNeeds and current status of Mo-99Tc-99m produc-tion in Japanrdquo in Proceedings of the Meeting on Mo-99 Produc-tion by (n120574) Method Tokyo Japan March 2012

[67] A Mushtaq ldquoProducing radioisotopes in power reactorrdquo Jour-nal of Radioanalytical and Nuclear Chemistry vol 292 pp 793ndash802 2012

[68] V S Le ldquoUtilisation of nuclear research reactor in Viet-namrdquo in Proceedings of the IAEA Advisory Group Meeting onOptimisation of Research Reactor Utilisation for Production ofRadioisotopes JAERI Tokai-Mura Japan October 1995

[69] V S Le ldquoDevelopment of alternative technologies for a gel-typechromatographic 99mTc generatorrdquo in Proceedings of the IAEAResearch Coordination Meeting Vienna Austria May 1994


[70] IAEA-TECDOC-852 Alternative Technologies for 99119898Tc Gener-ators International Atomic Energy Agency Vienna Austria1995

[71] K Tsuchiya ldquoAtatus of 99Mo- 99mTc production development by(n120574) reaction in Japanrdquo in Proceedings of the Specialist Meetingon Mo-99 Production by (n120574) Method Tokyo Japan March2012

[72] E Ishitsuka and K Tatenuma ldquoProcess for producingradioac-tive molybdenumrdquo World Intellectual Property OrganizationWO 2008047946 April 2008

[73] B J Jun M Tanimotor A Kimura N Hori H Izumo and KTsuchiya ldquoFeasibility study on mass production of (n120574) 99MordquoJAEA-Research Report 2010-046 JapanAtomic EnergyAgency2011

[74] Y Inaba K Iimura J Hosokawa H Izumo N Hori and EIshitsuka ldquoStatus of development on 99Mo production tech-nologies in JMTRrdquo IEEE Transactions on Nuclear Science vol58 no 3 pp 1151ndash1158 2011

[75] C Ross R Galea P Small et al ldquoUsing the 100Mo photonuclearreaction to meet Canadarsquos requirement for 99mTcrdquo Physics inCanada vol 66 pp 19ndash24 2010

[76] MC Lagunas-Solar PMKieferO F CarvachoCA Lagunasand Y P Cha ldquoCyclotron production of NCA 99mTc and 99MoAn alternative non-reactor supply source of instant 99mTc and99Mo rarr 99mTc generatorsrdquoApplied Radiation and Isotopes vol42 no 7 pp 643ndash657 1991

[77] M C Lagunas-Solar ldquoAccelerator production of 99mTc withproton beams and enriched 100Mo targetsrdquo in IAEA-TECDOC-1065 Production Technologies for Molybdenum-99 and Techne-tium-99m International Atomic Energy Agency Vienna Aus-tria 1999

[78] B Scholten R M Lambrecht M Cogneau H V Ruiz and SM Qaim ldquoExcitation functions for the cyclotron production of99mTc and 99Mordquo Applied Radiation and Isotopes vol 51 no 1pp 69ndash80 1999

[79] S Takacs Z Szucs F Tarkanyi A Hermanne and M SonckzldquoEvaluation of proton induced reactions on 100Mo new crosssections for production of 99mTc and 99Mordquo Journal of Radio-analytical and Nuclear Chemistry vol 257 no 1 pp 195ndash2012003

[80] Y Nagai and Y Hatsukawa ldquoProduction of 99Mo for nuclearmedicine by 100Mo(n 2n)99Mordquo Journal of the Physical Societyof Japan vol 78 no 3 Article ID 033201 2009

[81] J E Beaver and H B Hupf ldquoProduction of 99mTc on a medicalcyclotron a feasibility studyrdquo Journal of Nuclear Medicine vol12 no 11 pp 739ndash741 1971

[82] M B Challan M N H Comsan and M A Abou-Zeid ldquoThintarget yields and Empire II predictions on the accelerator pro-duction of technetium-99mrdquo Journal of Nuclear and RadiationPhysics vol 2 no 1 pp 1ndash12 2007

[83] K Gagnon F Benard M Kovacs et al ldquoCyclotron productionof 99mTc experimental measurement of the 100Mo(px)99Mo99mTc and 99gTc excitation functions from 8 to 18MeVrdquoNuclearMedicine and Biology vol 38 no 6 pp 907ndash916 2011

[84] H T Wolterbeek and P Bode ldquoA process for the productionof no-carrier added 99Mordquo European Patents EP 2131369 (A1)December 2009 Worldwide Patent 2009148306 December2009 EP 2301041 (A1) March 2011 US patent US 2011118491(A1) May 2011

[85] B S Tomar O M Steinebach B E Terpstra P Bode and HT Wolterbeek ldquoStudies on production of high specific activity

99Mo and 90Yby Szilard Chalmers reactionrdquoRadiochimica Actavol 98 no 8 pp 499ndash506 2010

[86] T J Ruth ldquoTwo routes to solving theMoTc isotope crisis directproduction of 99mTc and isotope separationrdquo in Proceedings ofthe CNS Workshop on the Production of Medical RadionuclidesOttawa Canada 2009

[87] E P Belkas and D C Perricos ldquoTechnetium-99m productionbased on the extraction with methyl-ethyl ketonerdquo Radiochim-ica Acta vol 11 p 56 1969

[88] G D Robinson ldquoA simple manual system for the efficient rou-tine production of 99mTc by methyl-ethyl-ketone extractionrdquoJournal of Nuclear Medicine vol 12 p 459 1971

[89] M P Zykov V N Romanovskii D W Wester et al ldquoUse ofextraction generator for preparing a 99mTc radiopharmaceuti-calrdquo Radiochemistry vol 43 no 3 pp 297ndash300 2001

[90] T le Minh and T Lengyel ldquoOn the separation of molybdenumand technetium crown ether as extraction agentrdquo Journal ofRadioanalytical and Nuclear Chemistry Letters vol 135 no 6pp 403ndash407 1989

[91] MMaiti and S Lahiri ldquoSeparation of 99Moand 99mTc by liquid-liquid extraction using trioctylamine as extractantrdquo Journal ofRadioanalytical and Nuclear Chemistry vol 283 no 3 pp 661ndash663 2010

[92] REBoydldquoTechnetium-99mgeneratorsmdashthe available optionsrdquoInternational Journal of Applied Radiation and Isotopes vol 33no 10 pp 801ndash809 1982

[93] K Svoboda ldquoSurvey of solvent extraction 99mTc-generatortechnologiesrdquo Radiochimica Acta vol 41 pp 83ndash89 1987

[94] ldquoRadionuclide generator technologyrdquo Radiochimica Acta vol41 no 2-3 1987

[95] A A Kuznetsov A A Kudrin and G E Kodina ldquoSemi-automatic 99mTc solvent extraction systemrdquo in Proceedings ofthe 7th International Symposium on Technetium and Rhenium-Science andUtilization Moscow Russia July 2011 abstract book4P13

[96] E Taskaev M Taskaeva and P Nikolov ldquoExtraction generatorfor [ 99mTc]sodium pertechnetate productionrdquo Applied Radia-tion and Isotopes vol 46 no 1 pp 13ndash16 1995

[97] O P D Noronha ldquoSolvent extraction technology of 99Mo-99mTc generator systemrdquo in Proceedings of the Conference onRadiopharmaceuticals and Labelled Compounds Tokyo Japan1984

[98] Y N Reshetnik A N Bykov G E Kodina and A OMalysheva ldquoSorption removal of Na 99mTcO

4from extracts

of extraction generator 99Mo 99mTcrdquo in Proceedings of the 7thInternational Symposium on Technetium and Rhenium-Scienceand Utilization Moscow Russia July 2011 abstract book 4P12

[99] S Chattopadhyay S S Das and L Barua ldquoA simple and rapidtechnique for recovery of 99mTc from low specific activity(n120574)99Mo based on solvent extraction and column chromatog-raphyrdquo Applied Radiation and Isotopes vol 68 no 1 pp 1ndash42010

[100] S Chattopadhyay L Barua A De et al ldquoA computerizedcompact module for separation of 99mTc-radionuclide frommolybdenumrdquo Applied Radiation and Isotopes vol 70 no 11pp 2631ndash2637 2012

[101] M Tanase A Kimura Y Morikawa et al ldquoRampD in on extrac-tion and concentration of 99mTc a preliminary study using Reinstead of 99mTcrdquo in Proceedings of the SpecialistMeeting onMo-99 Production by (n120574) Method Tokyo Japan March 2012


[102] S Tachimori H Amano and H Nakamura ldquoPreparation ofTc-99m by direct adsorption from organic solutionrdquo Journal ofNuclear Science and Technology vol 8 pp 357ndash362 1971

[103] V S Le ldquo 99mTc generator preparation using (n120574)99Mo pro-duced ex-natural molybdenumrdquo in Proceedings of the FNCAWorkshop on the Utilization of Research Reactors pp 216ndash223Japan Atomic Energy Research Institute 2003 JAERI-Conf2003-004

[104] V S Le and RM Lambrecht ldquoDevelopment of alternative tech-nologies for a gel-type chromatographic 99mTc generatorrdquoJournal of Labelled Compounds and Radiopharmaceuticals vol35 pp 270ndash272 1994

[105] V S Le ldquoRecent progress in radioisotope production in Viet-namrdquo in Proceedings of the Workshop on the Utilization ofResearch Reactors pp 308ndash314 Japan Atomic Energy ResearchInstitute 1998 JAERI-conf 98-015

[106] V S Le ldquoPreparation of chromatographic and solid-solventextraction 99mTc generator using gel-type targetsrdquo in Proceed-ings of the Workshop on the Utilization of Research Reactors pp187ndash192 Japan Atomic Energy Research Institute 2000 JAERI-conf 2000-017

[107] T Genka ldquoDevelopment of PZC-based Tc-99m GeneratorrdquoForum for Nuclear Cooperation in Asia (FNCA) no 2 March2007

[108] V S Le ldquoProcedures for the production of poly-zirconium-compound (PZC) based chromatographic 99mTc generator tobe available for clinical applicationrdquo in Proceedings of the FNCAWorkshop on the Utilization of Research Reactors pp 229ndash256Japan Atomic Energy Agency 2006 JAEA-Conf 2006-001

[109] V S Le C D Nguyen P Pellegrini and V C Bui ldquoPolymerictitanium oxychloride sorbent for 188W188Re nuclide pair sep-arationrdquo Separation Science and Technology vol 44 no 5 pp1074ndash1098 2009

[110] V S Le ldquoMedical radioisotope development radionuclidedevelopment group project no RRI-0168rdquo Report at ANSTOrsquosBoard Review Panel ANSTO 2009

[111] V S Le ldquo68Ga PET-radionuclide generator developmentrdquo inProceedings of the Seminar on Radiopharmaceutical Develop-ment Radiopharmaceutical Research Institute ANSTO June2009

[112] R E Boyd ldquo99Mo 99mTc generatorrdquo Radiochimica Acta vol 30no 3 pp 123ndash146 1982

[113] R E Boyd ldquoTechnetium generatorsmdashstatus and prospectsrdquoRadiochimica Acta vol 41 no 2-3 pp 59ndash63 1987

[114] J Gerse J Kern J Imre and L Zsinka ldquoExamination ofa portable 99Mo 99mTc isotope generator SUBLITECH(R)rdquoJournal of Radioanalytical and Nuclear Chemistry vol 128 no1 pp 71ndash80 1988

[115] L Zsinka ldquo 99mTc sublimation generatorsrdquo Radiochimica Actavol 41 pp 91ndash96 1987

[116] F Rosch A F Novgorodov and S M Qaim ldquoThermochro-matographic separation of 94mTc from enriched molybdenumtargets and its large scale production for nuclear medical appli-cationrdquo Radiochimica Acta vol 64 pp 113ndash120 1994

[117] R Chakravarty M Venkatesh and A Dash ldquoA novel electro-chemical 99Mo 99mTc generatorrdquo Journal of Radioanalytical andNuclear Chemistry vol 290 no 1 pp 45ndash51 2011

[118] R Chakravarty A Dash and M Venkatesh ldquoA novel electro-chemical technique for the production of clinical grade 99mTcusing (n120574)99Mordquo Nuclear Medicine and Biology vol 37 no 1pp 21ndash28 2010

[119] K Tagami and S Uchida ldquoElution behavior of Tc and Rethrough a Tc-selective chromatographic resin columnrdquo Journalof Radioanalytical and Nuclear Chemistry vol 239 p 643 1999

[120] X Hou M Jensen and S Nielsen ldquoUse of 99mTc from acommercial 99Mo 99mTc generator as yield tracer for the deter-mination of 99Tc at low levelsrdquo Applied Radiation and Isotopesvol 65 no 5 pp 610ndash618 2007

[121] M Fikrle J Kucera and F Sebesta ldquoPreparation of 95mTc radio-tracerrdquo Journal of Radioanalytical and Nuclear Chemistry vol286 no 3 pp 661ndash663 2010

[122] A Bartosova P Rajec and M Reich ldquoPreparation and char-acterization of an extraction chromatography column for tech-netium separation based on Aliquat-336 and silica gel supportrdquoJournal of Radioanalytical and Nuclear Chemistry vol 261 no1 pp 119ndash124 2004

[123] E Akatsu R Ono K Tsukuechi and H Uchiyama ldquoRadio-chemical study of adsorption behavior of inorganic ionson zirconium-phosphate silica gel and charcoalrdquo Journal ofNuclear Science and Technology vol 2 pp 141ndash148 1965

[124] R Rogers P E Horwitz and A H Bond ldquoProcess for recover-ing pertechnetate ions froman aqueous solution also containingother ionsrdquo US patent no 5603834 February 1997

[125] S Chattopadhyay S S Das M K Das and N C GoomerldquoRecovery of 99mTc from Na

2[99Mo]MoO

4solution obtained

from reactor-produced (n120574) 99Mousing a tinyDowex-1 columnin tandemwith a small alumina columnrdquoApplied Radiation andIsotopes vol 66 no 12 pp 1814ndash1817 2008

[126] R D Rogers A H Bond J Zhang and E Philip Horwitz ldquoNewtechnetium-99m generator technologies utilizing polyethyleneglycol-based aqueous biphasic systemsrdquo Separation Science andTechnology vol 32 no 1ndash4 pp 867ndash882 1997

[127] S K Spear S T Griffin J G Huddleston and R D RogersldquoRadiopharmaceutical and hydrometallurgical separations ofperrhenate using aqueous biphasic systems and the analogousaqueous biphasic extraction chromatographic resinsrdquo Industrialand Engineering Chemistry Research vol 39 no 9 pp 3173ndash3180 2000

[128] J E Young and J J Hines ldquoCompact automated radionuclideseparatorrdquo US patent no 6770195 August 2004

[129] H Bond J J Hines J E Young and E P Horwitz ldquoAutomatedradionuclide separation system and methodrdquo US patent no67870427 September 2004

[130] E P Horwitz and A H Bond ldquoMulticolumn selectivity inver-sion generator for production of ultrapure radionuclidesrdquo USpatent no 6998052 February 2006

[131] D R McAlister and E P Horwitz ldquoAutomated two columngenerator systems formedical radionuclidesrdquoApplied Radiationand Isotopes vol 67 no 11 pp 1985ndash1991 2009

[132] V S Le ldquoDevelopment of alternative technologies for a gel-type chromatographic 99mTc generatorrdquo IAEA-TECDOC 852December 1995

[133] J J Pinajian ldquoA technetium-99m generator using hydrouszirconiumoxiderdquoThe International Journal of Applied Radiationand Isotopes vol 17 no 11-12 pp 664ndash670 1966

[134] Q M Qazi and A Mushtaq ldquoPreparation and evaluation ofhydrous titanium oxide as a high affinity adsorbent for molyb-denum (99Mo) and its potential for use in 99mTc generatorsrdquoRadiochimica Acta vol 99 no 4 pp 231ndash235 2011

[135] S Meloni and A Brandone ldquoA new technetium-99m generatorusing manganese dioxiderdquoThe International Journal of AppliedRadiation and Isotopes vol 19 no 2 pp 164ndash166 1968


[136] J Serrano Gomez and F Granados Correa ldquo 99mTc generatorwith hydrated MnO

2as adsorbent of 99Mordquo Journal of Radio-

analytical and Nuclear Chemistry vol 254 no 3 pp 625ndash6282002

[137] Y Maki and Y Murakami ldquo 99mTc generator by use of silica gelas adsorbentrdquo Nipon Kagaku Zasshi vol 92 pp 1211ndash1212 1971

[138] J Serrano H Gonzalez H Lopez N Aranda F Granadosand S Bulbulian ldquoSorption of 99MoO

4

2minus ions on commercialhydrotalcitesrdquoRadiochimica Acta vol 93 no 9-10 pp 605ndash6092005

[139] V S Le Investigation on inorganic ion exchangers supportedon silica matrix [PhD thesis] Isotope Institute HungarianAcademy of Sciences 1985

[140] F Monroy-Guzman V E Badillo Almaraz J A Flores de laTorre J Cosgrove and F F Knapp Jr ldquoHydroxyapatite-based99Mo 99mTc and 188W188Re generator systemsrdquo in Trends inRadiopharmaceutical (ISTR-2005) vol 1 IAEA Vienna Aus-tria 2007

[141] T Braun H Imura and N Suzuki ldquoSeparation of 99mTc fromparent 99Mo by solid-phase column extraction as a simpleoption for a new 99mTc generator conceptrdquo Journal of Radioana-lytical and Nuclear Chemistry Letters vol 119 no 4 pp 315ndash3251987

[142] V S Le ldquoStudy on the titanium- and zirconium-molybdategel-type 99mTc generatorsrdquo Annual Report Vietnam AtomicEnergy Committee 1984

[143] J V Evans P W Moore M E Shying and J M SodeauldquoZirconiummolybdate gel as a generator for technetium-99mmdashI The concept and its evaluationrdquo International Journal ofRadiation Applications and Instrumentation A vol 38 no 1 pp19ndash23 1987

[144] P W Moore M E Shying J M Sodeau J V Evans D JMaddalena and K H Farrington ldquoZirconiummolybdate gel asa generator for technetium-99mmdashII High activity generatorsrdquoInternational Journal of Radiation Applications and Instrumen-tation A vol 38 no 1 pp 25ndash29 1987

[145] R E Boyd ldquoThe gel generator a viable alternative source of99mTc for nuclear medicinerdquo Applied Radiation and Isotopesvol 48 no 8 pp 1027ndash1033 1997

[146] V S Le ldquoDevelopment of alternative technologies for a gel-typechromatographic 99mTc generatorrdquo in Proceedings of the IAEAResearch Coordination Meeting Budapest Hungary February1993

[147] J A Osso Junior A L V P Lima N C da Silva R C Nieto andA C de Velosa ldquoPreparation of a gel of zirconium molybdatefor use in the generators of 99Momdash 99mTc prepared with 99Moproduced by the 98Mo(n120574)99Mo reactionrdquo in Proceedings of theInternational Meeting on Reduced Enrichment for Research andTest Reactors San Paulo Brazil October 1998

[148] V S Le ldquoInvestigation on the performance of polymer zirco-nium compound (PZC) for chromatographic 99mTc generatorpreparationrdquo in Proceedings of the FNCA Workshop on theUtilization of Research Reactors pp 90ndash104 Japan AtomicEnergy Research Institute 2004 JAERI-Conf 2004-010

[149] Y Hasegawa M Nishino T Takeuch et al ldquoMo adsorbent for99Mo- 99mTc generators and manufacturing thereofrdquo US patentno 5681974 October 1997

[150] M Tanase K Tatenuma K Ishikawa K KurosawaMNishinoand Y Hasegawa ldquoA 99mTc generator using a new inorganicpolymer adsorbent for (n120574) 99Mordquo Applied Radiation andIsotopes vol 48 no 5 pp 607ndash611 1997

[151] V S Le ldquoPreparation of PZC based 99mTc generator to be avail-able for clinical applicationrdquo inProceedings of the IAEAResearchCoordinationMeeting onDevelopment of Generator Technologiesfor Therapeutic Radionuclides ANSTO Vienna Austria Octo-ber 2004 httpapoanstogovaudspacehandle102383713

[152] V S Le ldquoChemical synthesis and application of zirconiumand titanium polymer compounds for the preparation of Tc-99m and Re-188 chromatographic generatorsrdquo in Proceedingsof the 2nd Research Coordination Meeting on Development ofGenerator Technologies for Therapeutic Radionuclides ANSTOMilan Italy April 2006 httpapoanstogovaudspacehandle102383714

[153] V S Le C D Nguyen V C Bui and C H Vo ldquoSynthesis char-acterization and application of PTC and PZC sorbents forpreparation of chromatographic 99mTc and 188Re generatorsrdquoin Proceedings of the IAEA Research Coordination Meeting onDevelopment ofGenerator Technologies forTherapeutic Radionu-clides ANSTO Daejeon Republic of Korea October 2007httpapoanstogovaudspacehandle102383715

[154] V S Le C D Nguyen V C Bui and C H Vo ldquoPreparation ofinorganic polymer sorbents and their application in radionu-clide generator technologyrdquo in Therapeutic Radionuclide Gen-erators 90Sr90Y and 188W188Re Generators IAEA TechnicalReport Series no 470 chapter 20 International Atomic EnergyAgency Vienna Austria 2009

[155] M Asif and A Mushtaq ldquoEvaluation of highly loaded lowspecific activity 99Mo on alumina column as 99mTc generatorrdquoJournal of Radioanalytical and Nuclear Chemistry vol 284 no2 pp 439ndash442 2010

[156] J S Lee H S Han U J Park et al ldquoAdsorbents for radioiso-topes preparation method thereof and radioisotope genera-tors using the samerdquo US patent application publication US20090277828 A1 November 2009

[157] AMushtaq ldquoInorganic ion-exchangers their role in chromato-graphic radionuclide generators for the decade 1993ndash2002rdquoJournal of Radioanalytical and Nuclear Chemistry vol 262 no3 pp 797ndash810 2004

[158] V S Le M Izard P Pellegrini and M Zaw ldquoDevelopment of68Ga generator at ANSTOrdquo in Proceedings of the 1st WorldCongress on Ga-68 and Peptide Receptor Radionuclide Therapy(THERANOSTICS rsquo11) ANSTO Bad Berka Germany June2011 World Journal of Nuclear Medicine vol 10 no 1 pp 73ndash89 P-023 httpapoanstogovaudspacehandle102383701

[159] R Chakravarty R Shukla S Gandhi et al ldquoPolymer embeddednanocrystalline titania sorbent for 99Mo- 99mTc generatorrdquo Jour-nal of Nanoscience and Nanotechnology vol 8 no 9 pp 4447ndash4452 2008

[160] R Chakravarty R R Shukla R Ram A K Tyagi A Das andM Venkatesh ldquoNanocrystalline zircona a new sorbent for thepreparation of 99Mo- 99mTc generatorsrdquo Journal of LabelledCompounds and Radiopharmaceuticals vol 52 supplement 1 pS500 2009

[161] R Chakravarty Development of radionuclide generator forbiomedical applications [PhD thesis] Homi Bhabha NationalInstitute 2011

[162] J V Evans and R W Matthews ldquoTechnetium-99m generatorsrdquoUS patent no 4280053 July 1981

[163] V H Tran and V S Le ldquoActivation analysis of trace elements intitanium-molybdate gel target used for pre-formed TiMo-gel-based 99mTc generator production and radionuclidic impurityof 99mTc pertechnetate eluaterdquo in Proceedings of the FNCAWorkshop on the Utilization of Research Reactors pp 105ndash111


Japan Atomic Energy Research Institute June 2004 JAERI-Conf 2004-010

[164] R Chakravarty R Ram RMishra et al ldquoMesoporous Alumina(MA) based double column approach for development of a clin-ical scale 99Mo 99mTc generator using (n120574)99Mo an enticingapplication of nanomaterialrdquo Industrial amp Engineering Chem-istry Research vol 52 no 33 pp 11673ndash11684 2013

[165] ADash F F (Russ)Knapp Jr andMRA Pillaia ldquo99Mo 99mTcseparation an assessment of technology optionsrdquo NuclearMedicine and Biology vol 40 no 2 pp 167ndash176 2013

[166] V S Le and N Morcos ldquoNew SPE column packing materialretention assessment method and its application for theradionuclide chromatographic separationrdquo Journal of Radioan-alytical andNuclear Chemistry vol 277 no 3 pp 651ndash661 2008

[167] I Zolle Ed Technetium-99m Radiopharmaceuticals Prepara-tion and Quality Control in Nuclear Medicine Springer BerlinGermany 2007

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of


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Industrial EngineeringJournal of


Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of


Journal of


Renewable Energy

Submit your manuscripts athttpwwwhindawicom


StructuresJournal of


RotatingMachinery


EnergyJournal of


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Nuclear InstallationsScience and Technology of


Solar EnergyJournal of


Wind EnergyJournal of


Nuclear EnergyInternational Journal of


High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Table 1 Current application of 99mTc for clinical SPECT imaging and activity dose requirement (lowast) The injection activity dose (mCi 99mTc)normally delivered in 1mL solution of the 99mTc-based radiopharmaceutical [167]

Organ99mTc


dose (lowast) Organ99mTc


dose (lowast)

Brain99mTc-ECD 10ndash20mCi

Kidney

99mTc-MAG3 5ndash15mCi99mTc-ceretec (HmPAO) 10ndash2mCi 99mTc-DTPA 5ndash15mCi

Lung

99mTc-MAA 2ndash4mCi 99mTc-Gluceptate 5ndash15mCi99mTc-DTPA aerosol 30mCi3mL

(10mCimL)99mTc-DMSA 2ndash5mCi

99mTc-Technegas 100ndash250mCimL Skeleton99mTc-MDP 10ndash20mCi

Thyroid 99mTc-pertechnetate 5ndash10mCi 99mTc-HDP 10ndash20mCi

Liver99mTc-IDA 5ndash10mCi

Heart

99mTc-Sestamibi 10ndash30mCi99mTc-sulfuralbumine

colloid 5ndash15mCi 99mTc-PYP 10ndash15mCi

Spleen99mTc-sulfuralbumine

colloid 2-3mCi 99mTc-Tetrofosmin 5ndash25mCi99mTc-red blood cells 2-3mCi Tumour 99mTc-Sestamibi 15ndash20mCi

available today two types of 99Mo sources of significantly dif-ferent SA values (low and high SA) can be achieved using dif-ferent 99Mo production ways Accordingly 99mTc generatorsusing low or high SA 99Mo should be produced by suitabletechnologies to make them acceptable for nuclear medicineuses The safe utilisation of the 99mTc generators is definitelycontrolled by the quality factors required by the healthauthorities However the acceptability of the 99mTc generatorto be used in nuclear diagnostic procedures the effectiveutilisation of 99mTc generator and the quality of 99mTc-basedSPECT imaging diagnosis are controlled by the generatoroperationelution management which is determined by the99mTc concentration of the 99mTc eluatesolution This alsomeans that the efficacy of the 99mTc generator used in nuclearmedicine depends on the 99mTc concentration of the solutioneluted from the generator because the volume of a giveninjection dose of 99mTc-based radiopharmaceutical is limitedThecurrent clinical applicationsof 99mTcare shown inTable 1As shown the injection dose activity of 99mTc-based radio-pharmaceutical delivered in 1mL solution is an importantfactor in determining the efficacy of the 99mTc solutionproduced from the generators So it is clear that the 99mTcconcentration of the solution eluted from the generator is theutmost important concern in the process of the generatordevelopment irrespectively using either fission-based highspecific activity 99Mo or any 99Mo source of low specificactivity It is realised that a complete review on the 99Mo and99mTc productiondevelopmentmay contribute and stimulatethe continuing efforts to understand the technological issuesand find out the ways to produce a medically acceptable99Mo99mTc generator and to overcome the shortagecrisis of99Mo99mTc supply So this review is to give a complete surveyon the technological issues related to the production anddevelopment of high and low specific activity 99Mo and to theup-to-day 99mTc recovery technologies which are carried outin many laboratories for increasing the effectiveness of 99Mo

utilisation The evaluation methods for the performance ofthe 99mTc-recoveryconcentration process and for the 99mTc-elution capability versusMo-loading capacity of the generatorcolumn produced using (119899 120574)99Mo (or any low specificactivity 99Mo source) are briefly reported Together with thetheoretical aspects of 99mTc99Mo and sorbent chemistrythese evaluationassessment processes could be useful for anyfurther development in the field of the 99mTc recovery and99Mo99mTc generator production The achievements gath-ered worldwide are extracted as the demonstrative examplesof today progress in the field of common interest as well

2 High Specific Activity 99Mo CurrentIssues of Production and Efforts of MoreEffective Utilisation

21 Production of High Specific Activity 99Mo High SA 99Mois currently produced from the uranium fission The fissioncross-section for thermal fission of 235U is of approximately600 barns 37 barns of this amount result in the probability ofa 99Mo atom being created per each fission event In essenceeach one hundred fission events yields about six atomsof 99Mo (61 fission yield) Presently global demand for99mTc is met primarily by producing high specific activity(SA) 99Mo from nuclear fission of 235U and using mainlyfive government-owned and funded research reactors (NRUCanada HFR the Netherland BR2 Belgium Osiris FranceSafari South Africa) After neutron bombardment of soliduranium targets in a heterogeneous research reactor thetarget is dissolved in a suitable solution and the high SA99Mo is extracted purified and packed in four industrialfacilities (MDS Nordion Canada Covidien the NetherlandIRE Belgium NTP South Africa) and supplied to manu-facturers of 99mTc generators around the world [2ndash12]CNEAINVAP (Argentina) ANSTO (Australia) Russia and








Fluid control unit

Chelex resincolumn



port









4




4


4


4

2minus


4



W in H2SO4

Mo in H2SO4

001 01 1 101

10

100

1000

10000

100000

1000000

kd

(mL

g)

H2SO4 (M)

(a)

0

1

2

3

4

5

6


99M

o or

188W

radi

oact

ivity

(120583Ci

)

WMo

(b)


2minus andMoO4


2SO


4

2minus andMoO4


4for MoO

4


4OH for WO

4





0 10 20 30 40 50 600

5

10

15

20

25

30

35

40

45

50

0

50

100

150

200

250

300

350

400

450

500

Radi

oact

ivity

(Ci)

Time (h)

99

mTc

spec

ific r

adio

activ

ity (C

i120583m

ol)

A

B

C


D

E

ATc minus 99m(max)

(a)

0 5 10 15 20 25

Elution time tb (h)

0

05

1

15

2

25

3

Yiel

d ra

tio (R

y)

(b)

(c) (d)









119894=1119860119889(119864119894)




= sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)





119877119910

=sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)

=sum119909=119894minus1



(1)







times (120582Mo


(3)


119905Max =[ln (120582Tc-99m120582Mo-99)]

(120582Tc-99m minus 120582Mo-99) (4)


119873Tc = 119873Tc-99 + 119873Tc-99m

= 1198730Mo minus 119873Mo = 119873


(5)


119878119860Tc-99m

=119860Tc-99m

119873Tc



(Cimol)

(6)99119898119879119888-Yield Ratio (119877




119894is the index



sum119894=1

119860Tc-99m(119864119894) = 120582Tc-99m times119894=119899

sum119894=1

119873Tc-99m(119864119894)

= 120582Tc-99m

119909=119894minus1

sum119909=0


times (120582Mo

120582Tc-99m minus 120582Mo)


(7)





100 (37) 1 6 0 1300 (111) 4 10 0 4500 (185) 6 12 0 61000 (370) 9 15 1 93000 (1110) 14 20 4 14



120582Mo120582Tc-99m minus 120582Mo

)


(8)


119877119910

=sum119894=119899

119894=1119860Tc-99m(119864119894)

119860Tc-99m(Max)

=sum119909=119894minus1



(9)


119887) for each













3powder




3powder form


3target












6] and molybdenum


5H3)]2ndashMoO

2 molybde-


2H2Cl

2) chloroform (CH

3Cl) benzene (C

6H6) and tolu-

ene (CH3ndashC










1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V












and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of
























Fluid control unit

Chelex resincolumn



port









4




4


4


4

2minus


4



W in H2SO4

Mo in H2SO4

001 01 1 101

10

100

1000

10000

100000

1000000

kd

(mL

g)

H2SO4 (M)

(a)

0

1

2

3

4

5

6


99M

o or

188W

radi

oact

ivity

(120583Ci

)

WMo

(b)


2minus andMoO4


2SO


4

2minus andMoO4


4for MoO

4


4OH for WO

4





0 10 20 30 40 50 600

5

10

15

20

25

30

35

40

45

50

0

50

100

150

200

250

300

350

400

450

500

Radi

oact

ivity

(Ci)

Time (h)

99

mTc

spec

ific r

adio

activ

ity (C

i120583m

ol)

A

B

C


D

E

ATc minus 99m(max)

(a)

0 5 10 15 20 25

Elution time tb (h)

0

05

1

15

2

25

3

Yiel

d ra

tio (R

y)

(b)

(c) (d)









119894=1119860119889(119864119894)




= sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)





119877119910

=sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)

=sum119909=119894minus1



(1)







times (120582Mo


(3)


119905Max =[ln (120582Tc-99m120582Mo-99)]

(120582Tc-99m minus 120582Mo-99) (4)


119873Tc = 119873Tc-99 + 119873Tc-99m

= 1198730Mo minus 119873Mo = 119873


(5)


119878119860Tc-99m

=119860Tc-99m

119873Tc



(Cimol)

(6)99119898119879119888-Yield Ratio (119877




119894is the index



sum119894=1

119860Tc-99m(119864119894) = 120582Tc-99m times119894=119899

sum119894=1

119873Tc-99m(119864119894)

= 120582Tc-99m

119909=119894minus1

sum119909=0


times (120582Mo

120582Tc-99m minus 120582Mo)


(7)





100 (37) 1 6 0 1300 (111) 4 10 0 4500 (185) 6 12 0 61000 (370) 9 15 1 93000 (1110) 14 20 4 14



120582Mo120582Tc-99m minus 120582Mo

)


(8)


119877119910

=sum119894=119899

119894=1119860Tc-99m(119864119894)

119860Tc-99m(Max)

=sum119909=119894minus1



(9)


119887) for each













3powder




3powder form


3target












6] and molybdenum


5H3)]2ndashMoO

2 molybde-


2H2Cl

2) chloroform (CH

3Cl) benzene (C

6H6) and tolu-

ene (CH3ndashC










1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V












and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















W in H2SO4

Mo in H2SO4

001 01 1 101

10

100

1000

10000

100000

1000000

kd

(mL

g)

H2SO4 (M)

(a)

0

1

2

3

4

5

6


99M

o or

188W

radi

oact

ivity

(120583Ci

)

WMo

(b)


2minus andMoO4


2SO


4

2minus andMoO4


4for MoO

4


4OH for WO

4





0 10 20 30 40 50 600

5

10

15

20

25

30

35

40

45

50

0

50

100

150

200

250

300

350

400

450

500

Radi

oact

ivity

(Ci)

Time (h)

99

mTc

spec

ific r

adio

activ

ity (C

i120583m

ol)

A

B

C


D

E

ATc minus 99m(max)

(a)

0 5 10 15 20 25

Elution time tb (h)

0

05

1

15

2

25

3

Yiel

d ra

tio (R

y)

(b)

(c) (d)









119894=1119860119889(119864119894)




= sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)





119877119910

=sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)

=sum119909=119894minus1



(1)







times (120582Mo


(3)


119905Max =[ln (120582Tc-99m120582Mo-99)]

(120582Tc-99m minus 120582Mo-99) (4)


119873Tc = 119873Tc-99 + 119873Tc-99m

= 1198730Mo minus 119873Mo = 119873


(5)


119878119860Tc-99m

=119860Tc-99m

119873Tc



(Cimol)

(6)99119898119879119888-Yield Ratio (119877




119894is the index



sum119894=1

119860Tc-99m(119864119894) = 120582Tc-99m times119894=119899

sum119894=1

119873Tc-99m(119864119894)

= 120582Tc-99m

119909=119894minus1

sum119909=0


times (120582Mo

120582Tc-99m minus 120582Mo)


(7)





100 (37) 1 6 0 1300 (111) 4 10 0 4500 (185) 6 12 0 61000 (370) 9 15 1 93000 (1110) 14 20 4 14



120582Mo120582Tc-99m minus 120582Mo

)


(8)


119877119910

=sum119894=119899

119894=1119860Tc-99m(119864119894)

119860Tc-99m(Max)

=sum119909=119894minus1



(9)


119887) for each













3powder




3powder form


3target












6] and molybdenum


5H3)]2ndashMoO

2 molybde-


2H2Cl

2) chloroform (CH

3Cl) benzene (C

6H6) and tolu-

ene (CH3ndashC










1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V












and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















0 10 20 30 40 50 600

5

10

15

20

25

30

35

40

45

50

0

50

100

150

200

250

300

350

400

450

500

Radi

oact

ivity

(Ci)

Time (h)

99

mTc

spec

ific r

adio

activ

ity (C

i120583m

ol)

A

B

C


D

E

ATc minus 99m(max)

(a)

0 5 10 15 20 25

Elution time tb (h)

0

05

1

15

2

25

3

Yiel

d ra

tio (R

y)

(b)

(c) (d)









119894=1119860119889(119864119894)




= sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)





119877119910

=sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)

=sum119909=119894minus1



(1)







times (120582Mo


(3)


119905Max =[ln (120582Tc-99m120582Mo-99)]

(120582Tc-99m minus 120582Mo-99) (4)


119873Tc = 119873Tc-99 + 119873Tc-99m

= 1198730Mo minus 119873Mo = 119873


(5)


119878119860Tc-99m

=119860Tc-99m

119873Tc



(Cimol)

(6)99119898119879119888-Yield Ratio (119877




119894is the index



sum119894=1

119860Tc-99m(119864119894) = 120582Tc-99m times119894=119899

sum119894=1

119873Tc-99m(119864119894)

= 120582Tc-99m

119909=119894minus1

sum119909=0


times (120582Mo

120582Tc-99m minus 120582Mo)


(7)





100 (37) 1 6 0 1300 (111) 4 10 0 4500 (185) 6 12 0 61000 (370) 9 15 1 93000 (1110) 14 20 4 14



120582Mo120582Tc-99m minus 120582Mo

)


(8)


119877119910

=sum119894=119899

119894=1119860Tc-99m(119864119894)

119860Tc-99m(Max)

=sum119909=119894minus1



(9)


119887) for each













3powder




3powder form


3target












6] and molybdenum


5H3)]2ndashMoO

2 molybde-


2H2Cl

2) chloroform (CH

3Cl) benzene (C

6H6) and tolu-

ene (CH3ndashC










1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V












and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of






















119894=1119860119889(119864119894)




= sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)





119877119910

=sum119894=119899

119894=1119860119889(119864119894)

119860119889(Max)

=sum119909=119894minus1



(1)







times (120582Mo


(3)


119905Max =[ln (120582Tc-99m120582Mo-99)]

(120582Tc-99m minus 120582Mo-99) (4)


119873Tc = 119873Tc-99 + 119873Tc-99m

= 1198730Mo minus 119873Mo = 119873


(5)


119878119860Tc-99m

=119860Tc-99m

119873Tc



(Cimol)

(6)99119898119879119888-Yield Ratio (119877




119894is the index



sum119894=1

119860Tc-99m(119864119894) = 120582Tc-99m times119894=119899

sum119894=1

119873Tc-99m(119864119894)

= 120582Tc-99m

119909=119894minus1

sum119909=0


times (120582Mo

120582Tc-99m minus 120582Mo)


(7)





100 (37) 1 6 0 1300 (111) 4 10 0 4500 (185) 6 12 0 61000 (370) 9 15 1 93000 (1110) 14 20 4 14



120582Mo120582Tc-99m minus 120582Mo

)


(8)


119877119910

=sum119894=119899

119894=1119860Tc-99m(119864119894)

119860Tc-99m(Max)

=sum119909=119894minus1



(9)


119887) for each













3powder




3powder form


3target












6] and molybdenum


5H3)]2ndashMoO

2 molybde-


2H2Cl

2) chloroform (CH

3Cl) benzene (C

6H6) and tolu-

ene (CH3ndashC










1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V












and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





















100 (37) 1 6 0 1300 (111) 4 10 0 4500 (185) 6 12 0 61000 (370) 9 15 1 93000 (1110) 14 20 4 14



120582Mo120582Tc-99m minus 120582Mo

)


(8)


119877119910

=sum119894=119899

119894=1119860Tc-99m(119864119894)

119860Tc-99m(Max)

=sum119909=119894minus1



(9)


119887) for each













3powder




3powder form


3target












6] and molybdenum


5H3)]2ndashMoO

2 molybde-


2H2Cl

2) chloroform (CH

3Cl) benzene (C

6H6) and tolu-

ene (CH3ndashC










1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V












and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of




















3powder




3powder form


3target












6] and molybdenum


5H3)]2ndashMoO

2 molybde-


2H2Cl

2) chloroform (CH

3Cl) benzene (C

6H6) and tolu-

ene (CH3ndashC










1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V












and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





















6] and molybdenum


5H3)]2ndashMoO

2 molybde-


2H2Cl

2) chloroform (CH

3Cl) benzene (C

6H6) and tolu-

ene (CH3ndashC










1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V












and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















1

2

3 4

5

6

7

8

9

10

11

V

V

V

VV

V

V

V

V

12

V












and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of























and 99mTcO4


3in the years








3

4

5

6 7

8

E C

Lead shielding

21EX

M

4

4

SV1

V2

(a)

Lead shield

Controller unit(CU)

PC

Rela

y ac

tuat

ion

Con

trolle

r

Com

mun

icat

ion


setup

(b)


Column 1 Column 2

Watervial

Salinevial

Product


collection vial

(c)


1and V







4



4




4

minus


4








4


2Cl



4 Sub-





119886)



119866 =119860Mo-99


119870 =119866

119898=


(10)




solution

B

ABEC resin column

was

te

From

DAlumina column

D



From

B C

From

A



99M

o so

lutio

nA

99M

o so

lutio

n in

(2 M

KO

H)

(a) (b)


50 100 150 200 250 300 350

250

200

150

100

50

0

2500

2000

1500

1000

500

0ab

c

ATc

(mCi

)

CTc

(mCi

mL)

K (mgMog)




119870(5100)

=172 times 1013


119870(5100)



















0 2 4 6 8 10


0

2

4

6

8

pH o

f mol

ybda

te so

lutio


MoO 2minus4

Mo7O 6minus24

0 2 4 6 8 10

MoO 2minus4



7MoO4


6minus + 4H2O (12)


7O24



4



pH o

f sol

utio

n

0

2

4

6

8

10

ZrMo gelTiMo gel




The 99mTcO4


4

minus

and Clminus ions















Lead shielding

TiMo or ZrMo gel


MF


Clean-up column

(a) (b)


Eluate volume (mL)

09 NaCl


15 gA

B99m TcOminus

4

A B

0 2 4 6 8 10 12 14 16 18 20 22 24

99m

Tc ra

dioa

ctiv

ity (c

pm)

Al2O3









15(OH)

30Cl

30(ZrO

2)sdot126H





H

OZr

Cl

Cl

15

HOO

O

O O O

OO

O

O

O O

OOO

OH H

HH

HH

H

H

HH

HH H H

HH

HHH

H

H

HH

H

H

H

Zr Zr ZrO

OHH

Scheme 1

H

OTi

Ti atom 1 2 3 4 5 6 7 8 9 10 (11rarr17) 18 19


H H H

HHHHH


O

O

ClClCl Cl


H


Scheme 2


4

2minus or WO4


4

2minus

orWO4


4


4



40Cl

80(OH)

80(TiO

2)97




4

2minus or WO4


4

2minus or WO4







(a)

(b)




119909M119910O119911(OH)

(2119909+2119910minus119911) where




(a) (b)

(c) (d)

(e) (f)








4




2SO




4minus119911(M)A

119894X119911-119894minus119896R

10158401015840

119896on the


119899H2119899+1


10158401015840



119886(C

119887H2119887+1

)119888[(CH


119890

(OM10158401015840)119891

(OH)119892

(CℎH2ℎ+1

)119901


V]






3

4

5

6 7E C

Lead shielding

8

8

9

12

(a) (b)


0 10 20 30 40 50 60 70 80Eluate volume (mL)

99m

Tc ra

dioa

ctiv

ity (c

pm)

(a)

Eluate volume (mL)

A

B

CD

2 4 6 8 10 120

(b)


2[57]








From step B

From A andPCM


A




Injectable 99m Tc


(a) (b)







2Amberlite BondElut






10

8

6

4

2

0

ab

Rete

ntio

n vo

lum

e (VR

) (m

L)

Eluate volumeVR







1

2

3

4 5

6

F

G

F

V1

V2

V3






2 nanocrys-







119899 =1198882

1198881

(13)


1198812

times 1198882

= 119896 times 1198881

times 1198811 (14)


119899 =1198882

1198881

= 119896 times1198811

1198812

(15)

where 1198811and 119881











1198811

= 119881119898

+ 119870119881

times 119881119878 (16)


1198811

= 119881119898

+ 119870119878

times 119878 (17)

where

119878 = 119898119888

times 119878

119881119878

= 119898119888

times 119881119878

= 119898119888

times1

120588Re

119870119881

= 120588Re times 119870119882

(18)


119870119881

times 119881119878

= 119870119878

times 119878 (19)


119881119881119878 and 119878 into

this equation

119870119878

=119870119882

119878 (20)

where 119870119878(mLm2) 119870

119881(mLmL) 119870



4











119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119881

times (119881119904

1198812

)] = 119896 times 119870119881

times (119881119904

1198812

)

(21)


119899 = 119896 times1198811

1198812

= 119896 times [119881119898

1198812

+ 119870119878

times (119878

1198812

)] = 119896 times 119870119878

times (119878

1198812

)

(22)



119881and 119881

119878)


119878= 20 119881

2= 50mL and 119896 = 095 the







4






119864which is


1198781of saline



119864




119896 = 119909 times 119910 (23)


119899 = 119896 times1198811198781

119881Eqvtimes

119881119864

1198811198782

(24)


119881 times 119898 = 1198811198782

(25)

119899 =1198811198781

119881Eqvtimes

119909

119881times

119910 times 119881119864

119898 (26)


2119878


The term (1198811198781



(119881119864



119899119879

= 119896119879

times1198811198781

119881Eqvtimes

119881119864minus119879

1198811198782minus119879

(27)


119879= 1 119881

119864minus119879and 119881

1198782minus119879








119899119875

= 119896119875

times1198811198781

119881Eqvtimes

119881119864minus119875

1198811198782minus119875

(28)

where 119881119864-119875 and 119881




119884 = 119891119864

times 119896 (29)






Table3As

sessmento

fnormalized

concentrationfactor

ofthec

oncentratio

nmetho

ds(electrolysis-a

ndsolvent-e

vapo

ratio


dsaren

otinclu

dedherein)

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

03M

NH

4OAc

+001M

NH

4NO

3QMA-

SepP

ak(130

mg)

(alumina)

20lowastlowast

10lowastlowast

mdash20

mdash05

10mdash

069

138

(40)

Knappetal

(1998)[43ndash4

5]

07M

AcOH+0132

(0025

M)N

aCl

QMA-

SepP

ak(130

mg)

(alumina)

1010

1010

1520

1066

09

45(45)

Mushtaq

(200

4)[50]

05M

AcOH+0025

NaC

lQMA-

SepP

ak(130

mg)

(alumina)

2510

1313

1515

1035

09

32(31)

Le(2013)

(forthis

repo

rt)

07M

AcOH+0025M

NH

4OAc

DEA

E-cellu

lose

(300

mg)

(alumina)

4045

4040

60

60

1075

08

60

(5-7)

Sarkar

etal

(2001)[4748]

01M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

4010

120

120

60

60

1050

095

475

(45)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

60

60

1067

095

63(60)

Le(2013)

(forthis

repo

rt)

03M

AcOH+005NaC

lDEA

E-cellu

lose

(025m

L)

(alumina)

2710

108

108

40lowast

35lowast

10100

085

97(94)

Le(2013)

(forthis

repo

rt)

05M

AcOH+01

NaC

lDEA

E-seph

adex

(012

5mL)

(alumina)

1510

2020

40

40

1033

09

30(30)

Le(2013)

(forthis

repo

rt)

05M

AcOH+005NaC

lIsosorb-MOX-

01(100

mg)

(alumina)

2010

1816

1515

1060

095

50(45)

Leand

Le(2013)

[58]

01M

AcOH+005NaC

lIsosorb-FS

-01(100m

g)

(alumina)

4010

4035

1515

1066

090

525

(50)

Leand

Le(2013)

[58]

H2O al

umina(

20g

)(ZrM

omolybdategel)

1616

mdash20

mdash30

10mdash

09

60(40)

Sarkar

etal

(200

4)[49]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

H2O al

umina(

15g)

(TiM

oZrMomolybdategel)

1110

460


7550

10557

095

112

(105)

Le(19

90)[57]

H2O M

nO2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

440


7050

10628

095

118

(104)

Le(19

90)[57]

H2O Ti

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

400


65

50

10615

095

105

(101)

Le(19

90)[57]

H2O Zr

O2sdotxH

2O(15g)

(TiM

oZrMomolybdategel)

1110

660


120

100

10550

08

76(70)

Le(19

90)[57]

Salin

erarr

H2O

Ag-resin

-alumina

(025m

Lsim260m

g)

(alumina)

1010

mdash20

30

mdash10

mdash098

653

(657)

Rudd

ock

(1978)[38]

Salin

erarr

H2O

Ag-resin

-alumina(

05g

)(alumina)

1010

150

150

25

25

1060

090

540

(500)

Leetal

(2013)

[40]

Salin

erarr

H2O

Ag-resin

-MnO

2(05g)

(alumina)

1010

145

145

22

22

10659

090

593

(530)

LeandLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-TiO

2(05g)

(alumina)

1010

140

140

20

20

1070

090

630

(570

)Le

andLe

(2013)

[58]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-11

sorbent(05g

)(alumina)

1010

155

155

275

25

10563

090

558

(53)

Le(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-microcrystalline

ZT-31

sorbent(05g

)(alumina)

1010

200

200

50

50

1040

008

320

(310

)Le

(2010-2013)

[6364

]

Salin

erarr

H2O

Ag-resin

-isosorb-FS

-01(05g

)(alumina)

1010

275

275

50

50

10550

095

522

(50)

Leand

Le(2013)

[58]

Salin

erarr

H2O

Ag-resin

-QMASepP

ak(130

mg)

(alumina)

1010

mdash10

mdash10

10mdash

082

82

Knappetal

(1998)

[4344

]


Table3Con

tinued

Metho


(CC)

(generatorc

olum

n)

Generator

elutio

nvolumes

Adsorptio

nRe

tentionvolumeo

fno

nsalinee

luent

passed

over

CC

Elution

volumeo

fsalin

eelutedfro


Values

calculated

using

119870119882or

retention

volume(

119881E-T

)

Values

calculated

basedon

experim

ent

parameters(exp

result)

Reference

119881Eq

v1198811198781

119881119864minus119879

119881119864minus119875

1198811198782minus119879

1198811198782minus119875

119896119879

119899119879

119896119875

119899119875

Salin

erarr

H2O

Ag-resin

-Bon

dElut-S

AX(100

mg)

(alumina)

1010

2510

20

20

10125

095

475

(47)

Blow

er(19

93)

[39]

Salin

erarr

02M

NaI

Dow

ex1times

8-resin

(10m

g)rarr

AgC

l10

g(alumina)

1010

6670

55

7510

120

08

75(77)

Chattopadh

yay

etal(2002)

[53]

002

MNa 2SO

4rarr

H2O

Pb-resin-alumina

(300

mg)

(alumina)

4560

4545

1510

1040

09

54(38)

Bokh

arietal

(2007)

[54]

lowastCon

centratorc

olum

niselu

tedwith

015M

NaO

Handfollo

wed

bypassingover

acation-exchange

resin

column

lowastlowastVa

lueisa

ssum

edbasedon

different

datasources


lues

ared

esignedfora

useful

life(14

elutio

ncycle

s)of

theg

enerator

with

outreplacemento

fthe

concentrator

column





99mTc concentrator










[43 44]











3A

Step A salineStep B


chloride

Not needed


evaporator


Das (2008)[52]

Injectable


A Saline eluent

Generator column




From B From A


B

Injectable


A Saline eluent

Generator column

Iodide eluent



From B


B

From A

Injectable


A Saline eluent

Generator column

Organic solvent

Evaporator


From C


B

C Saline

From

A


99m Tc 99m Tc99m Tc



4



4


4) has an



gt 03




Injectable



Generator column



From C From A B


C BWater rinse


Water rinse


A

Generator column



From C


B

From A B

C


Injectable



Generator column


Solventcollector

Alumina column BEv

apor

atio

nof

solv


evaporator

C

(acetone)

From C

Injectable

solution


Generator column

Saline eluent

300∘

C fu

rnac

e

Wastefrom A B

From C


B


C

Reductor

(SnCl2solution)

Injectable



Generator column

Sterile saline

Waste

From C Was

te o

f rin

se an

del

ectro

lysis


B+minus

PtPt

Alumina column

(water)

Water rinse C

General scheme 1B



99m Tc

99m Tc

99m Tc99m Tc

Injectable 99m Tc





1B A H2OB saline




1BA NH4OAc + NH4NO3

B waterC saline



B waterC saline


review)

1B


B waterC saline



B waterC saline



B waterC saline



B waterC saline





[57 59 60 104]


[51]

4BA NaNO3





[56]


4





4

minus





5 Summary





Acknowledgments


References


















































4by a single anion







4 188ReOminus

4by a single




















































4from extracts






























2[99Mo]MoO

4solution obtained


















4





































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of

















generator development: up-to-date recovery technologies for increasing the effectiveness of

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