SYNTHESIS, ION-EXCHANGE BEHAVIOUR AND ANALYTICAL APPLICATIONS OF SOME INORGANIC

MATERIALS BASED ON TETRAVALENT METALS WITH SPECIAL REFERENCE TO

TITANIUM (IV) AND ZIRCONIUM (IV)

DISSERTATION SUBMITTED TO THE ALIGARH MUSLIM UNIVERSITY. ALIGARH

in part ia l fu l f i lment of the requirements for the award o f the degree of

MASTER OF PHILOSOPHY IN

CHEMISTRY

BY

VIRENDRA KUMAR SAXENA

DEPARTMENT OF CHEMISTRY ALIGARH MUSLIM UNIVERSITY

ALIGARH (INDIA)

1 9 8 4

DSG35 / r

DS635

K. GOPAL VARSHNEY PH.D. ANALYTICAL LABORATORY

CHEMISTRY SECTION

FACULTY OF ENGG. & TECHNOLOGY

ALIGARH MUSLIM UNIVERSITY

ALIGARH-202001

(INDIA)

C E B f X r X C A T K

It Is to emrtttf that tlio work |ir«Miiit«d

in t h i s M.Riil. th«s l s i s an original eontrilratloB

of th« oandiAate «n4 i s «aita1>le for sntmiasion.

/ CG.Vari^nay /

C O N T E N T S

PAGE

AeKN0VIi:Tn!liW.T«T ( 1 )

LIST OF FUBLTCATIUNS (11)

LIST OF TABU.S ( i i i \

LIST OF PIGlifttiS < lv )

CHAPTLH ~ I

XNTROntjCTION 1

HT^FERt NObS 10

SHAPTfcR - I I

S¥NTHi;Sf8 Asm lON-EXCn*'ill(2i KiHAVlOUn OP TfTANIliM(IV>

AnSE?K>SIl.ICAri3 CA1?I0?3 BSCHASClIBj SiPARAflON OF

MI TAL IONS 13

EXfi;aiW:NTAL tk

fllSCUSSlON 3 *

HEFE RENOIR S 3S

CnAI^ER « 111

QUANT IT AT TVI. SEPARATION OF IRON FROM SOMi. MULTIVIT^TN-

MUtTP!lNER.\L FORNICATIONS USTNtt aiaCOKlUN(IV) ABSt.NO-

fflOSPHATl. COLUMNS %0

BXIHRllfeNTAL hi

niSCUSSlON %3

IKFBN^NCBS 46

A C K N O V L E T > O E M E M T

T •xpreaft my ulnoere thanicfi to ^r , !C.O«yartbney for hiii

able gaiffance anrt lcln«1 fiupervialoo an* t o 1*ir, K.T.Nasoen for

providltif; the reaearott f a o i l l t t c a , I also thnnk ^r«. Sanjay

Agarwal anA icanak Varahney for the ir Rraat help ''urtoi thta work,

The kind cooperation provWe«S by ^r» M.S.Rathl, Bolentlat 'n*,

Vadla Tnatttute of Htwalayam Geolo*»y, liehra«1un. If? frateful ly

ROknovl^O^eH in uaing the inatrumental f a c l l l t i e e of the

Tnatltate,

The klnfl, whole-hearted oooperatlon end affeotloa

extended to rm ceaseleaely durtng tb le perlo<i by tuy family

mefibera, frtends and col league a leaves me btg!»ly obliged and

l^ratefol,

Finally, T gratefully acknowledge the finanela1

aeaiatance provided by the Counoll of Soi<*ntifio an^ Tndtistrial

Reeeareh, New T»elhi.

/ V.IC.Saxena /

( 1 )

L I S T 0 F P O B L I C A T I O N S

1 . QUANTITATIVE SEPABATION OF IRON FROM SOME MULTIVITAMIN.

NULTIHINEHAL FORMULATIONS USING 2IRC0NTUM(IV) ARSENOIBOSFHATE

COLUMNS.

Anal .Let t . (Accepted>•

2 , SYNTHESIS ANB ION-« JBCHANCSI HBHAVIOUR OF TITANIUM (IV) ARSE!»-

SILICAIi: CATION ElC!IAN(2Sat ^PARATION OF METAL IONS.

Solvent Extract ion And lon-Sxchange (Co««unlcated).

( 11 )

h i s t O F T A B L E S

TAmi^ X

TABLE TT

TABU:i m

tABm IV

TABI£ V

TABUS VT

TABLE VII

TABLE V I I I

CUNMON COWORCTAL XON^XCHANGERS %

lON-ESCHANCfti CAPACtTY OF TTTANIC«!(TV) AHSLNa-

STLTCATli BY VARYING TB. GuNULKTBATlOH OF TIB

MI3n*:G SOLUTUN 16

lOH^XCnANGl. CAP^VCITY AND HIYSTCAt APS>I:,ARANCE

OP TAS*3 AFPSB mvATINQ TO VABIOUS TLMB IIATUt%:S 18

CHEMICAL STABILITY OF TAS.3 29

KQ V A L U E S OP so^iii ca^nm MCTAL I O H S on TAS.3

IN DiFFBec^rr mntA 5 1

mm BINARY Fi3PAElATlONS INVOLVING Pl»(II) OU

TITANIBM(IV) AflHiNOSILICATU COLCHIS 32

SOm SALILNT PEATUKCS OP TBE KLPASATIUJI OF

p e ( i i > rmn oimn MITAL IOHS I N SOMI syNTimxic

MixTum^s OK oC^AP COLUMNS 44

QOANTITATIVI- SEPARATION OF P e ( l l ) FROM 0TW.8

METAL IONS IN VAfllOlIS MULTIVITAMIN-MULTIMINERAL

FORMULATIONS MARfa Tt.T> IN INT>TA OH o^-ZAP

COLUMNS %5

( ill )

L I S T O F F I G U R E S

PAGE

FIGURE 1 STRUCTURE OF AN lON^XCHANGE RESIN 5

FIGURE 2 BLUTION BEHAVIOUR OF T A S . 3 AT ROOM TEMPERATUHE I9

FIGURE 3 pH TITRATION CURVES FOR TAS.3 USING DIFFERENT

TITRANT SYSTEMS 20

FIGURE k {fi TITRATION CURVES FOR TAS.I7 USING DIFi!ERBNT

TTTRANT SYSTEMS 21

FIGURE 5 THERMOGRAM OF TITANIUM(IV) ARSENOSILICATE 2%

FIGURE 6 INFRAREH SWICTRA OF T . A . S . I N H * FORM 25

FIGURE 7 X-RAY DIFFRACTION PATTERN OF T . A . S . - I 7 26

FIGURE 8 SEPARATION OF P b ( l l ) FROM OTHER METAL IONS

ON TAS.3 COLUMNS 33

( ir )

C H A P T E B - I

XNTBO1I0CTION

1

l0B<-«zeli*ng0 has becone one of the aost important

t«ehnli|u«« In rooent t l i ie . An lon-«xoh«nger nay be defined as

a «tH>«tattO« Containing lout ilhloli can be exchanged with other

iona of the satRe e lectr ic charge anfll aupplled from an external

aource. As t h i s definition i s too wide for practical purposee,

an ion-exchanger for use as an analytical tool i s defined as a

solid oontainini; a oationlc or anionic species supplied fro« an

external solut ion. An ion-exchanger may be eith<^r organic or

inorganic in nature. For excfitple, T»owcx-50 i s an organic ion-

exchange resin vhlob consis ts of a highly cross-linked sulfonated

polystyrene polymer net woifc» If free sulfonic acid groups are

present, the resin i s said to be in H form. When i t i s immersed

in an aiineous medium i t behares as a strong acid end the sulfonic

acid groups are completely dissociated. Hie acidity of the

aqueous medium within the resin structure i s approximately 5N, Tf

i t i s treated with alkali the acid i s neutralised and the exchanger

conirerted to the appropriate cat ionic form. A similar exchange of

cations w i l l take place between the resin in one oati(Niic form

and another cation in solutitm. The process may be represented

by the following equatitm, where R ' represents the poljraer net work

and A and B are cat ions .

R"*A* • B* ' ' ' H~B* • A*

Tbe structure of the polymer net work of an ioB-ezchanfer

r«slii Is ^own In figarc^l. The anions present In the solutions

do not take part in the exohanjEe process to an appreciable extent

since consideration of Donnan equilibrium and the insolubi l i ty

of th^ exchanger anions shows that the anion in solutiim oaa aot

enter the net worlc. An ion--exohanger may be a strong or a weak

depending upon the nature of the groups possessing the exchangeable

ions in the matrix. Further, i t nay be a cation exchanger or an

anion exchanger. TablooT summariaes some of the ooisnonly known

ion exchange res ins . Organic resins have great u t i l i t y in

analytical chemistry as thoy can be used for achieving sonw very

d i f f icu l t separations. The most striking examples being the

separation of rare earths* different valency s tates of a neta l ,

amino acids, and sugars. The reasons of the ir wide spread

analytical applicotions are as follows}

(1) The high ohemiocl and rr^chaniocl s t a b i l i t y .

(2) Bigh ion-exchange capacity.

(3) High exchange rates .

(h) Poss ib i l i ty of selecting the fixed ionic groups and the

degree of cross linking of the matrix.

However, the main drawback has been their ins tab i l i ty at high

temperatures and under the environment of strong radiations.

For th i s reason an interest was revived in the study of inorganic

ion exchangers as they are superior to the organic resins in their

thermal s tab i l i t y and resistance to ionising radiations. For

example, s e o l i t e s oan be used as catalysts for gas reactions at

temperatures well above the range in i^toh the resins mre s table .

3

^ ^^lXv\1^ uiCh flKi-d chiiirfi?^

(^ C o u n t e r ions

.r-\ \Z) C 0 - i 0 n s

FIG. 1 STRUCTURE OF AN ION-EXCHANGE RES!

(SCHEMATICS)

a 5

3

m

S

O o

s o o

CO

o « « o

fi

>4

t a

0

2

I

i

m u B

JO

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ex • • 1

i f \ 4 KN

* *

6 «H

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•«•

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vo

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o\

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VD •

01

m 0

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yt

• 0 0

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• 0

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e « s » 0 |Q

•0 S a tH UD B M

• •e •>

• 0 0

•> •H

a g « 0i«

• 0

0

«0 IB « 1 h 0* p4 CO 0 1-t 6 fl) ja 0

§ *-< •

8 O * M

O • W Q ID CD

-. - * S i g a o u n o 0*

(0

o CO 4 * er S t -B P i l

JB U » Q o Xi CE! &« O

§ ^ 1

H

0

P-(

h

^

5

^

M « » e 0

tf\ Cs> 01

t <e ¥ i 0

69

KN VO

1 0

« 4* ^ »-• 0 8

g H

«

ti r-* u « .0

i!

lf\ 'H CM

•s «B ^ 0

o o

o »

1-4 o a

• 1 ^

B

» B

•**

K O At

2 S o o I f ? *?

S 8

*-• t O ^ K B B H • 44 O ^

• «• »•

u &> 8 O

a o

5

w B «4

B Ji O B

l M « iN

C4 « I (M • a <B •

B.O • U fi O

4 BJi O B

<C I 8 CB

S.O « h fi O

ei

V6 tt% • • a tr\

0 •

K\

0 •

1 ^ m

o 0 0 <B (D « n •o 8 a g « «

• 0 0 H CO 0 «H

e 0

6 g fi

u «B CD (3

m «o C CD

e € «

o o

«9 O

o u CD tt CO

n 8 CO

§ ^

o o

« • 4» •»

« « CP

• fi <

a M

I

I

o-^ ^- ' •^ CM

1? i-<

0

8 CD

s B

»

o fin

T

«>

I B.

CD M

* o .U 6 CO - H

5 » CO

5

Tli« laorsanlo Ion txehangcr gel* offer adTantagoo In the

deoontaalnatlon of cooling water In nuelear reaetora irhere both

the tetnperature and radtatione ler^l are high, Furtheraore,

oryatalllne ion exchangers with regular frame work atruoturea

often show higher s e l e c t i v l t l e e than materials with irregular

gel struoturea.

Synthetic inorganic ion exchangers have earned the ir

position in the f ie ld of Analytical Chemistry during the last

two decades, Amphlett ( i ) and Clearfield (2) mey he regarded

as the pioneers of the f ie ld who have init iated and developed

the field to the present day s tatus . On the hasls of their

struotare and chemical nature these materials can he c lass i f i ed

into the following s ix groupsf

( i ) Insoluble acid sa l t s of polyvalent metals.

(2) Hydrous oxides of polyvalent metals,

(3) Salts of heteropoly ac ids ,

(%) Insoluble hexaoyanoferrates(II).

(5) Miscellaneous inorganic exchangers e , g , merearbide s a l t s

and potaasium polyphosphate,

(6) Synthetic aluminoailicates.

Although the materials of all the above categories find

important applications (5-5)t our main emphasis will be on the

insoluble acid salts of polyvalent metals, as they possess much

satisfactory pn>parties which are produced by combining generally

the oxides of group III, IT, V and VI of the periodic table, A

large oowbinations of such materials have been prepared by mixing

6

phosphorlQ, ars*Blo, m>ly1»dlo, tunf^stto, antlaontc and vanaAlo

aolda with sireoaluai, tltanltim^ t i n , tliorliw» oerluiB» iron,

ohronltM, ntobtum, tantalun, bla»uth, nickel , cobalt a t e .

AfnongBt the large aumher of Inorganic Ion exohfingerm

alrconluwi fibospfiate Is probably th© wost ex^»aptlve^y studied

tBatcrtal so far both In the aworphoua and oiyatal l lne formn.

On tbe baelfi of ebemloal analysin Baetale baa easlgned a atruo<

tnre^ tbown belows

HgPOj.O

Zr 0

on

n^voyo OB

Sr 0 ^Z— .HgO

HgHlj.O HgPOJ.0

P 0

OH

Tts manifold applloatlcma (2) l l luatrate well Ita

li»portanG« as an ion exchanger. Tor example, i t has been

ut i l i sed for the purification of coolant water in oloaed cycle

nuclear reactor ayetews, in which the teesperature of water i e

approximately 3CK) C and the preteure ia about 100 at* . Another

important uae of amorphoue alroonium phoaphate baa been in the

portable renal dialyeia ayatema. Urea, which ia the compound

dialyaed from the blood atream in the greateat quantity by

a r t i f i c i a l fcidneya ia not readily aorbed by common aorbente.

In order to remove i t from the dialyaatea, i t ia hydrolyaed to

ammooiiMi carbonate by the ensyme ureaae. The dialyaate ia then

7

pasMd 0T»r • eoluMB oontainlni! aotlrated oharooal and xireoaiUM-

phoaphata. Xlreonlam phoaf^ate takaa up anmonlttar Ion or forwa

tntaroalatad eompoand with MH.« Other organic oontaalnanta ar«

Borhad by the activated oarhon. Production of apherlCPl part i c l e s ,

precipitation of a l l l ca gel on to the zlroonlum phoaphate and

production of fluroethylene (fluroplaat) coatlni; are nome of the

further atte<npt8 to Improve the atabl l l ty of slrconlun phoaphate

for Its %rlder use In lon-exohange technology* This material has

also found application In water aoftenlng prooenees. ft haa also

been used In gas chromatography for the separation of atsines on

i t s columns using NH as the mobile phase. Similarly, ohloro-

hydrooarbone and oeroaptans haye been e f fec t ive ly separated on

crystal l ine potassium asirconium phosphate. Becent applications

of zirconium phosphate include i t s cata lyt ic behaviour* Use of

inorganic ion exchangers as membranes i s important from the

industrial point of view* They would permit a higher temperature

to be used and a greater eff ic iency to be attained as compared

to the organic resins* Exchange membranes have been made from

hydrous thorium and slroonium oxides which have been found useful

for demlneralisatlon of saline water* Another interesting

application of inorganic ion-exchangers has been their use as

antloorrosive additives, tabody and Ronay prepared a thin sheet

of exchanger which, when placed around a s tee l tube inserted in

the earth, acts as a protector*

Since titanium resembles xlrconlum in i t s ebemical

behaviour the ion axobaBgers based on t h i s metal have also

8

rtotir^d attention. Some of the Important Materials of th i s

type whioh have shown good ion exchanica behaviour and analytical

appiioationii are tltanittai-silloate (6)* titanitm i^iosphate (7<-8),

hydrous titaniuli dioxide (9'*12), titanium vanadate (13)t t itaniun

hydroxide (i4<»17) and t i taniun tungstoarsenate (16)•

Heoently double Belts have received attention as ion

exchangers. They have shown a more pronising ion-exchange

behaviour. Zirooniuis phosi^osilicete i s pnibably the f i r s t of

t h i s c l a s s which has been used for the isolat ion of plutoniun

(19-21)• Similarly titanium phosphoeilicate has been used (22)

for the separation of radionucletde. Quite a good nunber of

double s a l t s have been prepared in these laboratories based on

Sn(lV), Th(IV), Ce(TV), Cr ( l l t ) and Zr(TV) which have shown sowe

interesting ion-exchenge properties (23-^1)# Amongst them Zr(IV)

arsenostl icate and Zr(TV) arsenoi^osphate have i l lurtrated the ir

applications in the analysis of rooks, a l loys , end pharmaceuticals.

They have also shown a good chemical, thermal and radiation

s tab i l i ty (42) ,

Although the fieli^ of inorganic iou'-exchnngers has seen

a tremendous development in the recent past, one of the most

baffling problems has been to produce a real ly reproducible and

and stable material. Furthermore, i t i s important to select a

material useful for the solution of some real problems. Our

recent approach to u t i l i s e inorganic ion exchangers In the analysis

of pharmaoeatical products has made them more promising. The

9

pr»««Bt wofic i« In ooDtlnuntion of oor sucb an t f f o r t , A oew

ion «xohanK« nat tr la l baaed on t ltaniun, arsenic and s i l icon

has iMen prepared and i t s ion exchange properties 8ti:^ied a«

eoMmi^sed in Ohapter-TT. Since t h i s material needs sons wore

studies before i t s utiliasation in the analytical f ield can be

made, another naterial of the aatie c lass v i s . zirooniini(IV)

arsenoi^osphate has been selected for the analysis of s«KHe

drui; formulations, Chapterollf summarisses such a study.

10

MEFBgHCBS

i r 0»9.A«phletty ^looxsanlo Ion Eacoliaaxerti", ElMYisr, London

(196*).

2 . A,Clearflel« (Ed,), "Inorganic Ion Sxctiange Matertalf",

cue Press Inc . , Boos ttaton, Florida (1982).

3, H.f.Valton, Anal.C!i«m«, ^ , 15R (19^)*

%, y.Pelcarolc and V.Vesely, Talanta, ig , 219 (1972),

5 . V.Pskarek and V.Vosoly, Taianta, 1^, 1245 (1972),

6. G.T.nesal, B.H.Baxl, Indian J.Teohnol,, 16(5) , 20^-6 (1978).

7. Yu.B^nolmatov, R.T.Fogodin, Neorgan lonoobmen Materialy,

(2 ) , 86-8 (1980).

8» Yu.A.Ajana'ev, N.B.Savanofe, L.T.Aashipa, SP STL 512 Ichp - 1»82,

(1982).

9 . Taiceyosbl Sasaki, Tu.Koiaatsu, Yoshinori Fajikl , Sep.Sci.

Teohnol, i 8 ( l ) , A9~58 (1983).

10. T.M.Valentine, R.A.J.Sanbell, Nuol.Chen.Waste Manage,

2(2) , 125-30 (1981).

11. T.N.PerektaoshSTa, L.M«Sharygin,T.O.MaIykh, Radiokfiimiya,

2*(3), 295-8 (1982).

12. li.A.BersehkoTa, A.A.GuasalroYS, To.A.Baliyrenko, Neoi^an.

Tonool>Men Materially, (£) , 72-6 (I98O).

13* Myong Rwa-Kin, T.K.Su.U, TT Sang Kia, Punsok HWahak,

(3) , 15-21 (1979).

1%. M.t>.«etenekov, Y.A.Yasileirskii, Yu.Y.Egora, T.A.Nedobukh,

RadlokhiMlya, 24(%), 419-2* (1982).

11

15* B,p«Nlkol*skll, E.D.Makarova, F.A.Bellnskaya, L.N.TolkaohaTa,

N«orgaii,fonoo1)iii«n Matertaly, (2 ) , 26«>51 (1980),

16. B.P.Nlk«l*Bkii, fi.P.MakaroTa, F.A.Belinakaya, L.N.Talkaoheva,

Ibid, (2 ) , 51-72 (1980).

17» F.A.BellnPkaya, E,t»,Makarova, Tnnoylobmen lonor^etrlya,

i f 33-9 (1976)•

18, Jagdish Prasad Rawat, Vieaood Akhter Khan, Anii.Chin*,

62 (9-10), 525-32 (1979),

19* n.Nauffiaan, Kernanergie, 6, 173 (1963)*

20, K.y.Barsukova and O.N.nadionoTa, Badtokhlmiya, 14, 225

(1972),

21, R.Ootae, P.Sohenken* W,T)ole8legen, L,H,Baet6le and Mn< hont,

J.Inorg.Nuol.Chen,, 2§t 665 (1974),

22, S,J,Na(nrl, D.HuyB and L.H.Baetale, ib id , , ^J, 4317 (1971).

23, S.G.Varebney and A.A.fChan, Talonta, 2^, 528 (1978),

24, K,G,Tarshney and A.A.Kban, J.Inorg. & Huol.Chea,, 41 , 241

(1979).

25* K,G,Tarsbney, S,Nabeed, A,A,Khan, S,N,Taadon and C,B,Gupta,

Cbroaatograpbla, 12, 413 (1979).

26, K.G.Tarabney and A.Pranadaa, J,Liq,Cbroaatogr*, 4 , 1245

(1981).

27, K.G.Var^ney and A.Prenadaa, Ibid, , f , 915 (1981).

28, K.G.Yarabney and A.Pranadat, Indian J,Cb«n,, ^ , 841 (1981),

29, K,6,Tari^a«y and A,preiMidaa, 8«pn,Sol, & Tech,, 16, 793

(1981),

30, K,G,Varabn«y, A.A,Kliaa and A.Praaadaa, Annall Dl Chl«loa,

579 (1981).

12

31 . K.6.T«r«iineyf U.Sharna, S.Ranl and A.Premaaas, Sapn.Sei, A

Tech., 12(3)• 1527-43 (1982).

32. K.O.Tarshney, S.Agrawal and K.Varehney, Ib id . , 18(1), 59-72

(1983).

33 . K.O.Taridiney, S.Agrawel, K.Varshney, U.Sharma and S.Ranl,

Badloohem.RadlonaI.Lett., ^ ( 3 ) » 141-46 (1983)*

34. IC.O.Varehney, S.Agrawal & S.Varshney, Anal.Lett. , 16(B9),

685-92 (1983).

35. K.O.Varshney, K.Vftreliney and S.Agrawal, Sepn.Sol. & Yeoh.,

18(10), 905-15 (1983).

36. K.G.Varshney, S.Anwar and S.Z.Qureelil, Anal.Lett . ,

16, 1093 (1983).

37. K.O.Varshney, S.Agraval and K.Varshqey, Ib id . , 16(A17)

(1983).

38. K.G.Varshney, A.A.lQban, A.Meheehwerl, S.Anwar and U.Sharma,

fnd.J.Tech., 22, 99-103 (1984).

39. K.O.Tarshney, S.Agrawal and IC.Vareliney, J.Llq.Chromatogr.,

2 , 201 (1984).

40 . K.O.Tarshney, Uma aiarma and S.Ranl, J.Tnd.Chen.Soo.,

61(3), 220-24 (1984).

41 . K.G.Varshney, San jay Agrawal, Kanak Varahney and S.Anvar,

J.Llq.Chromatogr. (Tn Press) .

42. X.G.yarrtiney, S.Agrawal, K.Varshney, U.Sharma and S.Ranl,

J.Radloanal.Nuol.Chen., 8£(2) , 299-308 (1984).

C H A P T E R . IT

SYNTHCSTS AN1> lON-EXCHANOfc; DLHAVIQUR OF

TITAtilOM(TV) ARSENOSILICATE CATION ESCllANGERt

SEPARATION OF METAL IONS

13

INTHQIIUCTIOW

Tltanlttm and slroonlum based Inorganlo lon-axohangera

hare shown t b e i r aaaljrttcal iiiipoi*toBC« In many ways, Zr(T?)

and Ti(TV) arsanophosphates have been used in the a n a l y s i s of

cer ta in a l l o y s and rooks ( 1 ) . Also t i tanium tuni;8toarsenate

has been used (2) for the separation of Pb(TT) from Mg(TT),

Zn(Tt) , Mn(TT) and Ca(TT), Certain other double s a l t s based

on t i tanium have received at tent ion as inorganic ion-exchangers

such as phosphos i l ioate , taolybdoiSiosphate, tungstophosphate and

vane^ophoepbate (3-6) • Howeirer, as the l i t e r a t u r e sbowti

arsenoeil icates arc the least studied materials. Only siroonium

and t in based arsenoeil icates hove been reported (7*8) eo far,

although, the single arsenate and s i l i c a t e sa l t s have shown

ear l ier (9tlO) a much promising ion-exchange behaviour. Tn

view.of th i s titaniumoarsenostliCQte has been taken up in t h i s

study to evaluate i t s ion exchange behaviour and analytical

potential . The following pages summarize the results of such

an e f for t .

14

EXPERIMENTAL

Tit an Ian tetrachloride used in t h i s study was a product

of Flulca A6, Chemishe Fabrlk CH~9470 Buohs, while solium

metasll lcate and nrsenlo acid were ohtalned from H.TI,11,Poole

(England)• All the other reagents and chewtoels wore of

Analar grade,

TnstrmeentG used for the various studies are given belowf

SI, Studies Btade fnstruisent used and i t s Hodel/Make

1, fifl seasureraents fl! meter. Model LT-10, Clico (India).

2 , Infra»red absorption Becktnan IR-'SO spectrophotoineter,

3 , X-ray diffraction Philips x-ray diffraction unit with a Ctt-Koc target ,

4 , T.G.A, Themobalanoe Consisting of a Cohn RG Electrobalance (Model 2050) and a nichrone wound res i s t ive furnace,

SYNTHESIS OF THfc lOW-EXCHANGE MATbRlAL

Different samples of titanium arsenosi l icate were

prepared by the following methodt

Aqueous solutions of titanium tetrachloride arsenic acid,

sodium s i l i c a t e and RNO. (IM) were mixed in equal volumes with

15

eonstant s t trr lng . The gel obtained was kept at room temperature

(30 C) over night anrt f i l t ered , washed with demlnerallzed water

<nMV), and dried at %0 in an a ir oren. The dried product was

cracked in IWW t o obtain granules which were converted into the

H form with IM HNO.. A few samples were also prepared by

refluxlng the mother liquor obtained by the abore method in

4M H5I0- for 100 h. Table-II suwstariaes the sal ient features of

the various samples prepared under varying conditions.

IQN SCHANCaS CAPACITY ( l . e . O . ) iiiir-- I III I •• " ' - - - i • II III I • ii i i I i i i i i n l i—1 *•!

The ion-exchange oepacity was detensined by the oolumn

process taking 1 giR of the satnple (H form) in a glass tube

( i , d . ' ^ 1 cm), f itted with the glass wool at i t s bottoa. A

solution of IM NaNO, (%00 ml) was passed through the coluom

maintaining a flow rate of'-^10-12 drops/min. and the effluent

was t i trated with a standard UaOH solut ion. The Na^^xchange

capacities (mllllequlvalents per dry gran) of different samples

are given in Table-TI.

Bepending upon the highor ion-«xchange capacity and

apparent chemical s tab i l i ty sample TAS-3 was selected for the

detailed s tudies .

THERMAL STABILITY

Several 1 gm portions of the sanple TAS-3 were heated

at different temperatures in a muffle furnace for 1 hr each and

the l . e . c* was determined as usual after cooling them to the

16

TABLE « n

IOII lCHANq& CAPACITY OF Ti(IV^ ARSBKQSILICATE SAMPLES FHEPAmP

IT YABTINC THB CQNCKiJTHATION qP tms; MIHIM^ SOMTTtOKS

Sample No* Mixing oonoentratlon of the oomponente I . e . e . 1 i (meq/dry gw)

Volttne Ratio of mixing

TAS - 1

TAS > 2

TAS - 3

TAS - k

TAS • 5

TAS - C TAS - 7

Volttne Ratio of Mixing

TAS > 8

TAS - 9

TAS - 10

TAS - 11

TAS . 12

TAS - 13

TAS - tk

TAS - 15

TAS - 16

Volane Ratio of Mixing

TAS - 17*

\

1

{

1 t

Tl

O.IM

0.2M

O.IM

0.^

1,0M

0.2M

0.5« 1 t

Tl

O.IM

oaM O.IN

O.IM

0,2N

0.2M

0.6M

0.8N

l.OM

1 t

Tl

©•3K

1 S

HAS

0.5M

O.IM

0.2M

O.IM

O.IM

0.^

0.5M

1

NaAs

O.IM

0.2M

0.5M

l.OM

0.5M

0.5M

0.5M

0.5M

0.5M

1

nAa

0.3M

1

Nasi

O.IM

O.IM

O.IM

O.IK

O.IM

O.IM

0.5H t 1

NaSl

O.lM O.IM

O.IM

O.IM

O.IM

O.IM

O.IM

O.IM

O.IM

f 1

Nasi

0.3M

1.15 1.12

1.26

1.23

0.81

1.18

1.01

1.05

1.15

1.20

1.02

1.06

0.99

0.89

0.90

0.83

0.00

Tl « TltaalttM t e t r a o h l o r l d e , HAs • Arsenic s o l d , NaAs « Dl sodlua arsenate , NaSl • Sodlua s i l i c a t e .

Reflttsed for 100 hours .

17

roon ttt«f»*r«tttr«. Table-TII tumiarlxet tbe re su l t s ,

ELPTIOK tHAYIOUR

To finA out the •lutioti bebavtour, IN NaNO. solution was

paeaed through a colunsi oontalning 1 gin of the exohanger in

H^ form anA the effluent was collected in the fractions of 10 ml.

These fraetioDS were t i trated against a standard NaOR solution

to determine the B eluted out. The histograms are shown in

figure•2.

pE TITBATIONS

They were performed by the isethod of Topp and Pepper

(11) as followst

500 mg of exchanger (B form) was taken In each of the several conical flasks to which were added equimolar solutions

of metal chlorides and the ir corresponding hydroxidee in different

•olume rat ios , tbe final volume being 50 ml. The jM values of the

solutions were recordei' after keeping them over night for e q u i l i ­

bration and were plotted against the mi l l l equivalents of OH"

added. Figures 3 and h summarize the pB t i trat ion curves for

the SMiples TAS-3 and TAS-17 respectively.

COMPOSITION

Composition of the samples TAS-3 and TAS-i? was determined

by the standard methods (12,13) es described belowt

18

O

M

»: a

o

<

o to

I •>

O <B

c m & 4* e 6 m

1 <

CO

i i o

I o

o H

S

<

« M C (9

•J "

w4 (B CP i ti-V ffi «B i

c

a ja

e

I

e

ft 4* B

8 1 o

s CO

p.

\ 0

• <•>*

s •

o OB • O

fi •

o

in o •

o

u Si

19

O o < tn I

(/)

<c H o CSC

"o O « j X UJ

o

- J UJ

6

e 9

e 9

P « t t t ) « j ^ H i ° t«|oui (U

20

" ^

A NaOH / NaCl

O KOH / KCl

LiOH / LiCl

OS 1,0 1.5 2 O

m mo les 0 f OH added

2.5

FIG 3 f H TITRATION CURVES FOR TA.S DIFFERENT TITRANT SYSTEMS

•3 USING

21

3 -

4 NaOH /NaCl

O KOH / KCl

© LiOH / L iC l

J_ J., O S

. _ i 2 O 2 S l O t. 5

m mo I f <s of OH added

FIG.4 PH T I T R A T I O N C U R V E S FOR TA5-I7 USING DIFFERENT TITRANT SYSTEMS

22

1>«tT»twtlon »f Titmluw and Si l icon

To an aecuratoly weighed amount (100, 200 and 500 ng)

of the frawdered savitple irae added a small amoant (10-15 «il) of

eonoJIgSO^ and the alzture was evaporated to dryness on a steam

bath. The treatment was repeated with additional oono.HgSO^,

The residue was taken ap In 5 nl ooncH^SOji and 200 • ! of t'ffV,

digested to dissolve the soluble sa l t s and f i l t ered , washed and

Ignited. The Ignition product was weighed to give the tota l

weight w^ of oxides (TlOg * S10n)« tt was then treated with

a mixture of OP and n^S^^ followed by evaporation npto dryness.

The residue was Ignited and weighed to give the weight (w.) of

TlOg. The difference i»j-W2 6*^^* the weight of SlOg,

T>eterwlnatlon of Arsenic

An accurately weighed amount of the powdered sample was

dissolved In a minimum amount of oonc.RgSO;!. After dilution to

about 100 ml with vm titanium was precipitated with a freshly

prepared aqueous solution of oupferron (65(), f i l tered on a

Whatman No. k2 f i l t e r paper. The f i l t ra te was boiled with Rlf0«

and a few drops of 30^ H Og to oxidize the organic matter. After

cooling I t , 1 ml of T)*fV and 5 ml of conc.nCl (both previously

boiled and cooled) were added followed by addition of 2 ml of

411 KT. The solution was kept for 10 min in a stoppered flask

and t i trated against O.OlN sodium thiosul|rfiate after adding

5 ml of i01( starch solution •

23

THBRMOOKAYIMETRTC AWALTSIS

Pigtti« 5 thows tiM peroent weight l o s s occurred in ttie

eawplea TA8.3 and TAS-l? on heating then upto 1200 C*

IWFRA^KP gTUPTES

t . R , atuflles were perfonne^^ osine; the KBr p e l l e t rnethofl.

Figure 6 lAiowa the c o ^ a r a t l v e 1 , 8 . spectra of aemples TAS- 3

anfl TAS-17.

X RAY STUy>ICS

Figure 7 ebovi^ the x-ray d i f f r a c t i o n patterns of sample

TAS-17* Howevor no remai^ablc peck was ohtained for sample TAS-3.

CHE fTCAL STAB7LITY

The chemical s t a b i l i t y In various so lvents was detemined

for the sample TAS-3 as fo l lows!

250 lOg port ions of the sample were kept with 23 ml each

of the various s o l v e n t s for 2k hrs with intermittent frttaking.

3 ml of the supernatant l iquid was evaporated t o dryness and

redlsso lved in 23 ml of t)MV, Titanium, arsenic and s i l i c o n were

then determined separate ly by the standard methods given bel«wt

(a) WTERMINATIUN OF TITAHTUM

3 ml of the sample so lut ion which i s in equil ibrium with

t i tanium a r s e n o s l l l o a t e waa mixed with 0 . 3 «1 of a 30)K HjOLtolutioa

24

O 2 0 0 4 0 0 & 0 0 ® 0 0 1000

T»mp«ratur9 ( C )

12 0 0

riG. 5 THERMOGRAM OF TITA^JiUM 15V)ARSEN0S1L!CATE

25

c

c

'r-

& 0

<o

ao

4 0 0 0 SOOO HOOO 15 0 0 lOOO

Wav!? number (Cm~^ 3

3 OO 2 5 O

FIG.6 INFRARED SPECTRA OF T.A.S.IW H FORI

26

m <

PI

J L^.^ i L 1 <tt lA o

o> n

m fM

fV

P--

m

»

ij>

^ • • ^

6»

o» O • > —

© ns

1

<

U-O Z Ci LU H f

< O.

2 O

u «^ cr:

o

>-<

1 X

6 u.

^ ) i i u « ; y |

27

and th« Toluae was nade 25 nl by addinx 10% eulphurlo aold in a

•oluaetrlo flask* The absorbanoe of the ooloar de^eloped was

neasured at h±0 nil against the reagent blank (14) .

<b) BBTERMINATION OF ARSENIC

I t was done by the nolybdenum blue method (15)* The

reagent solution was prepared by nising 10 nl of solution A

(1 gm amaoniun nolybdate dissolved in 100 nl of 5N H SO. ) with

1 ml of solution B (0.150 gm hydrazine sulphate dissolved in

100 ml of t MW) and diluting the mixture to 100 ml. It was

prepared fresh dai ly , 10 ral of t h i s reagent were added to the

sample solution (5 n l ) and the mixture was heated on a steam bath

for 15 minutes. After cooling, i t was transferred to a 25 ml

volumetric flask and diluted upto the mark with the reagent

solution. Tb*} absoxbance was taken at 850 n^ against the reagent

blank.

(C) PETEHMIWATION OF SILICON

5 ml of the sainple solutioa was mixed with 0.5 nl of 101(

annonium nolybdate and 0.1 nl of 50% H„S0^. The solution was

diluted upto 25 ml in a volunetrlc flask. The absorbanee was

taken at %20 n|i against the reagent blank (16) .

Table IV sumariases the solubi l i ty of the material in

various solvents . ~ -._

•••- ••* . . • i . ' ^

TABLE.IV

mmiCAL STABILITY OF TITANIUM ARSbNOSILTCATO. (TAS.3)

28

S o l u t i o n s (25 n l )

IH HNOj

SM HNO.

m BNO5

IM RgSO^

2M HCl

4M HCl

IM BCIO^

2?! HCIO^

IM CH.COOn

l*f nCOOB

0.05W NaOH

O.IOM NaOH

O.IOV KOR

IW KNO5

m NH^NO-

IM NaNO.

Affloui

T l

DA

I»A

BA

BA

TA

DA

1 .40

2 . 0 3

0 . 0 0

0 . 0 0

0 . 0 0

0 . 0 0

0 . 3 1

0 . 3 1

0 . 0 0

0 . 3 1

i t dl88oliW(9 In

a An

flA

BA

BA

!»A

nA

T»A

0.00

0.60

0.48

0.59

0.91

0.92

0.97

0.00

0.00

0.00

WR 1 "'

SI

DA

l>A

?»A

T)A

DA

DA

0.00

0.00

0.00

0.00

0.06

0.30

0.10

0.00

0.11

0.12

T»A Dl«solTt/l appreciably.

29

PISTBIBOTIOW OTimiSS

Blstrlliation stadlss were perforwed on sample TA8-3 for

liiffeiwn't «ot«l ioas to •arloiis iiolira»i^« an followftt

290 mg of the exchanger beade In H form were equillhrated

with the selected solvents (25 n l ) e i ther by shaking for 3«-4 h

or by keeping at room temperature for 24 h. The i n i t i a l metal

ooROf^ntration in the solution was so adjusted that i t may not

exceed y% of the to ta l ion-exchange capacity of the material and

the determinations were carried out •olumetrloally using EnrA

as a t i t rant (17) .

The S^ values as suramarized in Table—T were obtained

by the formula

d • "7" * I (w^/s)

I m I n i t i a l amount of the metal ion in the solution phase,

F m Final amount of the metal ion in the solution phase.

Y •> Volume of the solution (ml).

A « Amount of exchanger (gm).

SEPARATION ACHIEIfEII

The 6o-iOO mesh sized part ic les of the sample TA8-3 (2 gm)

30

iB th« B^ foFM w«re paok«0 In a glata tabe liaTiaK ao Intamal

dlaMeter of ^^0.6 on and f i t ted with the filaaa wool at Ita bottOM,

7h« ooluwtt v i i Viahed thoroughly with tmv and the analsrte aolution

was loaded on i t , maintaining a flow rate of "^2-3 dropa/nln.

All the metal lone except Pb(lt) were eluted out In O.OIM HNO.«

Pb(TX) was then leached oat with m NH-W,, The flow rate for

elutlon was kept 10-12 drops/win. The effluent were t i trated

for the ir metal Ion contents using B TA as a t i t rant . The salient

features of the separation are shown In Table ft and Figure 8«

31

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• • • * • • • • s * * ^ *

o o o o o o o o t o o o o

s^ 4> < )<% S S & 8 Oi

KN Q O ^ CM MS 5 < <<s

• • • § « •

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g m u o w 2 I .S S SB H O c s

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PISCUSSION

A n«w Inorg^nlo ion exchanger tltanlttn(tY) ar»eno«llloate

hat haan ayntliattsatf and atndied for i ta ion aisohanga profH»rtiaa,

The aNorphoua phaae of th i s vaterial (TAS-3) ahowa an appraeiahle

ion exchange oapaoity (1.26 meq/gai) nnd a good thermal a t a h i l i t y .

However, i ta crystal l ine phaae (TAS-17) ahows sero ion exchange

capacity, ft may Tie doe to the reason that on refluxing the

material for 100 hours the protogenio groups are los t and an

uncharged matrix i s fonned. In t h i s respect titanium arseno-

s i l ioa te d i f fers from other materials of th i s c lass in general.

For exsTople zirooniun i^osphate has been reported to gain i t s

ion-exchange behaviour after crys ta l l i zat ion , Sini larly i t

has been obserred in case of zirconium arsenophosphate (18) that

on refluxing for lOO hours in 4M RNO. It becomes crystal l ine with

an itsprovement in i t s ion exchange capacity. The x-ray diffraction

pattern (Figure 7) of TAS-17 shows several peaks with the following

d-Talaest

9.3015, 7 a 3 2 0 , *.9238, *.5715, 3.5309, 3.3984, 3.1839»

3.0153, 2.8465» 2.6882, 2.5902.

As Table-TTT shows, titanium arsenosil icate retains 571(

of i t s ion-exehange oapaoity even on heating upto 400 C lAiowlng

a remarkable thermal s t a b i l i t y . However beyond 400 C i t loses

i t s iiHi exchange capacity abruptly. The material, therefore,

promiaes i t s use at high temperatures.

35

HI* pH t i trat ion ounres (rigures 3 and 4) Indleate that

while the aworphous naterlal (TAS-3) releasee the R ioaa

ai^preolAbly* the erystal l toe «at«rial (TA8*i7) Ao«« BOt. This

hehaviottr i s in aocordanoe to the ir Ion exchange capaolt ies .

Furtbermoi^, 'rAS-3 shovs a very high rate of exchange for Li* as

compared to Na and K at the i n i t i a l stage, to general the

pR t i t ra t ion carves indicate a bifanctlonal behaviour of t h i s

acid s a l t .

The infra*red spectra of t ltania«(IV) arsenosll icate

both enorphoos and crys ta l l ine , are shown in Figure 6. They ~1 indicate the peaks around 500» 900, 1^0 and 3500 en . The

peaks in the x-ray patteni of TAS-17 are more d is t inct and

sharper than in that of TAS-3 peiiiaps due to i t s crystal l ine

nature. The above mentioned peaks oonfira the presence of

metal hydroxide, arsenates, s i l i c a t e s and water Molecules. The •1 peak at 1600 cm also represents the weakly bonded protogenic

groups responsible for the ion exchange eapaoity.

Figttre-5 ehows the therwograms of TAS- 3 and TAS-17.

As i t i s c lear from these curves TAS-3 experiences a more weight

loss on heating upto 1200 C as compared to TAS-17. Also, i t s

weight remains constant from 200 to 700 C. But TAS-17 has one

more step during th i s range. Since TAS-3 i s having a gel

character i t contains more water molecules than TAS-17 which i s

crys ta l l ine . And hov|Eie« higher loss in I t s weight can be

visual ised. The i n i t i a l weight loss vpto 200 C i s due to the

36

lo t* Of • x t t m a l water aoloottlos. Further l o s t at the higher

teiiperature Indioatee eon<1entatloii»

Figure 2 showt the e lot lon hehaTlour of TAS»3 In^lleatiiie

alwost a complete elotlon of the H lone In the f lrat 150 • !

of the ef f luent ,

Tahle>TV tumtnarlzee the retulte of the s tah l l l t y study

of tltanlum(TV) arsenoellloate In varlout to lventt . It Is

observed that the eubetanoe le not very stable In strong aold

media partloularly BNO., ^9^4 "Q^ ' CSl. However In HCIO , It

seems to be quite stable anil also In organic aolds# Alkalies

and sa l t s lltce SNO«t I ^NO* and Na!iO« do not dissolve the

substance to an appreciable extent .

A study of the distr ibution-coeff ic ients (Table-IV) on

tltanluiR(IV) arsenosllloate points out I t s extra ordinary

se lec t iv i ty for Fb(TI), On the basis of such a study separation

of Pb(TT) froiB several metal Ions has been t r i e d . As Table-VT

and Fig, 8 Indicate the exchanger can successfully be employed

for the separation of Pb(TI) from numerous metal Ions, The

results obtalne*^ are aoourate as the error range Is very low.

The advantage of the method Is that the separations oan be effected

on a email column containing only ^^2 gm of the exchanger and

using common and Inexpensive solvents l ike UNO. and NII.NO_, Also

the method Is rapid and the same column can be used several times

without a lose of I t s ef f lc lenoy. Lead Is one of the chief

37

pollatiBg •a ter ia la found In aquatle anA enYlronaantal asratems,

Tta ranoval and separation la , therafore, of great algnlfleanea

and tltanlun araenoailloate offera Ita u t i l i t y In auoh a eaaa.

The oliamlefll analyala of the salt reveal a the nolar

oo«npo8ttlon of TAS-3 aa 2t5s5 (TltAatSl) and that of TAS-17 aa

2tlt4t (TlsAsfSl), It oonflma the view that on refluxlng, the

protogenlo groups are lost generally attached v l th the arsenate

and s i l i c a t e groups thus resulting In the lost; of the oat Ion

ejEOhange properties of the nater la l . This point, however, needs

further Investigations based on the structural studies, before a

definite conclusion i s drawn In t h i s regnrd.

38

1 , K.6.Yar8liney» S.Afsrawal, ICYarsbney, A.Prtmadaa, M.S.Rattai,

P.P.Khanna, Talanta, 2 0 ( 1 2 ) , 955-8 Cl983)#

2 . J.P.Rawat, M.A.Khaii, Ann,Clii«,, 62.t 525-32 (1979) .

3« S.J.NaqTly T).noy8 an(f L.H.Baetsla, J.Xnorg.Nucl.Chem.,

2 1 , %317 (1971) .

4 . C.Czllioloy, L . S z l r t e s and L.Zslnka, Radio Cliem.lfadioanal*

L e t t , , 8 , 11 (1971) .

5 . J.P.Rawat and R.A.Khan, Ind.J.Chen. , IgA, 925 (1980) .

6 . N.jr.Singh and S.N.Tandon, Ibid, Ig^t * 1 * (1980) .

7 . IC.Q.Varahney, S.Agrawal and K.Varehney, Sep.Sol .Teohnol . ,

1 8 ( 1 ) , 59 (1983) .

8 . IC.G.Vareihney, A.A.Khan, A.Maheeh^arl, S.Anwar and U.Stiarma,

Ind.J .Teoh. , 22, 99-103 (1984) .

9 . M.Qureshl and S.A.Nabl, J.Tnorg.Nucl.Chem., 22 , 571 (1967) .

10, G.T.WeMl, t».R.Baxl, Tnd.J.Teotinol., 1 6 ( 5 ) , 204-6 (1978) ,

11 , N,E.Topp and fC,W,Pepper, J ,Chc«,Soc, , 3299 ( I949 ) .

12 , N,n.Faniian, "Standard Methods of Chemloal Analyala**, VT Edn. ,

Vol , 1 , fl,Yan Nostrand Company, I n c . , Princeton, Tfow Jersey

(1963) .

13 , A.T.Togel, "Textbook of Quantitative Inorganic Analyela",

TT rev.Edn, Clay (The Chancer P r e s s ) , Bungay (1978) ,

14, P,l>,Snell and G,T,Snel l , Color lvetr lo Methods of Analys i s" ,

IIT Bdn. , Yol . IT, p. 438, B-Yan Nostrand Company, I n c . ,

Princeton, !fsw York (1959) .

39

15. B.B.Sand«ll, "Colorinmtrlo DaterainatIon of Traces of Netala**,

Vol. I l l t P» 282, Inter Science publlaherfi, H»w York (1959)•

16. F.W.Snell and C.T.Snell, "ColorIwetrio Methoffs of Analytrla**,

•ol» IIAt p« <J99» ''^.•an Nostrand Company, Inc . , Princeton,

New Jersey (1959)»

17. C.N.Rellley, R.W.Schmlrt an«1 Pawzys, J.Chem.Educ., ^6, 555

(1959).

18. Berardl l l i , P.C.Galll, A.Lagenestra, M.A.MasKnool and

K.G.Varahney, J.Cheia.8oo. naltons Transactions (In Press) .

G H A P T E B - I I I

QUANT ITATIW SEPAflATlON OP IRON FROM SOME

MOLTIVITAMIN-HULTIMINERAL FQHMDLATIONS

USING ZIRCONICM(IV) ARSBNOPHOSHUtE COLUMNS

40

B«t«mlBatloii of nifMral • lenente In oomMretal

{thamaoeuttoals lias bean a eab.l«ot «f seiraral Invaatlgatlona

using different analytical teobnlfiuaff (1-S)« In wost of the

aatermlnation methods, severe Interferences are oaased due to

presence of certain tons 8n< separations are thus necessary

prior to the tfeteralnatlon* Korkisoh et a l , reported (9) that

in the determination of netal ions in nultivitainin preparations

by atomic absorption spectrophotometry, iron interferes seriously

which was separated on Bowex 1X8 anion exchange re a in prior to

the determination* This chapter snomariKes a taethod to separate

iron frors other taetal lone in some mttltivltamin-iBUltliiiinerel

fortBulations using zirconiuto(XT) areenophof<phate as a cation

exchanger, which hee ear l i er shown (10) good ion-exohange

ch a rac t e r 1 st Ic s •

41

BXFBRIMEliTAL

gACEHTS ASP CHEMICALS

The stroonyl chlorld* and trltodium orthophotphate nmd

In th i s study were the B«^,H, (Eogland) products whlls disodlnn

arsenate was an E.Merck ('Darmstadt) product. Other reagents and

ohenlcals vere of analsrtloel grade.

SYNTHESTS OF TOE lON«EXCnANGB MATERIAL

Zlroonlais(IV) arsenophosphate was prepared hy the method

reported earl ier (10) as followst

Aqueous eolutlone (0«05 N) of zlroonyl chloride, dlsodlum

arsenate and trlsodlum orthophoepheto were mixed In equal volurees

and the pB of the nlxture was flsEed In the range O*! by adding

n i t r i c acid with ccmstant s t irr ing . The gel thus obtained was kept

at room temperature (30 C) OTemlght and f i l tered , washed with

demlnerallxed water (DMV), and dried at 40 C In an a ir ovea. The

drle'^ product was cracked In IWW to obtain granules which were

converted Into the R form with IM HN0»« It was heated at SMX) C

for 1 hour before using for column operations as the phase (<<->SAp)

obtained by th i s treatment Is hlp^hly selectlire for Iron (lO).

SEPARATIONS

Synthetic Mixtures

Two grams of the 6o«»100 mesh slsed part ic les of the exchanger

42

(cX,*IAP) in B^ form w«r» U8«d for eoluim oporatlonf In « glass

tubo having an intamal dlaiaetar of --'O.S oa, Tha oolamn wan

waahaA thoz^ughly with WX and tha Mixture ( i n l ) waa loaded on i t ,

Maintaining a flow rata of '-^O.l ml/nin. Tha alution of the natal

ions other than Fa(TT) was done hy O.OlM HNDj. Fa(11) was than

elutad out with %M HNO. with the alMultaneoua regeneration of the

column. The rate of flow for the elution wa« kept'^^l nil/«in«

The netal ions in the effluents were d«»temined qaantitatlTely by

ET»TA t i trat ion exoe{>t S(T)i, which was detertnined floiBe>photomet~

r l c a l l y . The sal ient features of the separation of Pe(TT) fro«

other metol ions in aoiae sjmthetio mixtures are susmarized in

Table-VTI.

Capaules and Tablats

One capsule/tablet was boiled with 3 ml of oono. HCl and

50 nl of IMW vaa added. After f i l t er ing through a Vhatnan No« %

f i l t e r paper the solution was nade upto 100 nl with DMV, One nl

of thia solution was evaporated to almost dryness and the raaidue

was taken in ^^ 1 nl of T)^« It was than loaded on the eolunn of

the ion exchanger by the saiM» procedure as described for the

synthetic nixturaa. All the netal ions except iron were elutad

out with O.OIM HNO- (nax.vol. required ~ 150 n l ) . Iron was f ina l ly

removed with 4M HMO- (nax.vol, raquired ^ 5 0 nl) and datamined

quantitatively by EDTA t i trat ion at ffl 4 and ualng Cu-pAN indicator.

The raaulta are sunnarisad In Table-VTIT.

43

PISCPSSION

nM Miln feature of th«8« studies has been the separation

of Iron from other minerals In some multlirltamln-multlmineral

fomulatlons on an Inorganic ion exohanirer* fhe iMthod i s

applicable to the synthetic mixturee (Table-TII) ee well as to

the dntft samples (Table-VITT) and i s based on the high se l ec t iv i ty

of zirconiuiR(IV) areenophospliate for iron. As the results show

the method appeara t o be accurate and precise with a coeff icient

of variance <. 2 . It has i l lustrated the use of zirconlu»<IV)

arsenophosphate in the analysis of pharmaceutical products.

44

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46

BBFBIIKNCES

1* M«l,A«Cooper, J.Ballaatine and A,l)«Woolfron, J.Fham,

Pharmaool., 21,* *05 (1979).

2 . B.StankoTlo, M.l^uganAsle end M.Jeliklo, Ptaamaxle, ^S.* ^^^

(1977).

3 . flanlel J .J ,Sul l ivan, Aasoc, off Anal.Chem,, 22., 1156 (1976).

4 . Hanlel J.J.Sullliran, ABBOC, aff Anal.Chem,, 60, 1350 (1977).

5. S.W,Bl«liara anfl P.M.El-SammRn, Mloroohefli.J., 22, 4*2 (1977).

6. F.Pellcrln and J.P.Ctoulle, Ana.Pharm.Pr,, 21 , 189 (1977).

7. Penttl O.Koaonea, Anne<^arle Saloaen anrf Annalllsa Klevmlnen,

Flnn.Cben.Latt., 4., 136 (1978).

8 . S,A,Ii)l«R:inawy, M.T,Wala«h, M.r.Abon-Bakr and T.Z.Blala,

J.Virag nea., 2» 151 (1975).

9 . J.Korklsch and H.Hucbner, yilcroobliit.Acta, £ , 311 (1976).

10. K.G.Varshney, fC.Varahnay and S.Agrawal, Sep.Sol.TaotiBol.,

18, 905 (1983).