a rapid extractive spectrophotometric method for the determination

Research ArticleA Rapid Extractive Spectrophotometric Method for theDetermination of Tin with 6-Chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzopyran

Ramesh Kataria1 and Harish Kumar Sharma2

1 Department of Chemistry and Centre of Advanced studies in Chemistry Panjab University Chandigarh 160014 India2Department of Chemistry Kurukshetra University Kurukshetra Haryana 136119 India

Correspondence should be addressed to Ramesh Kataria rkatariapuacin

Received 31 May 2014 Revised 3 July 2014 Accepted 31 July 2014 Published 14 August 2014

Academic Editor Gerd-Uwe Flechsig

Copyright copy 2014 R Kataria and H K SharmaThis is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

An extractive spectrophotometric method for the determination of the trace amounts of tin has been carried out by employing6-chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzopyran (in acetone) (CHTB) for the complexation of the metal ion in HClmediumThe colored species thus produced is quantitatively extracted into dichloromethane and shows the maximum absorbanceat 432ndash437 nmThe method obeys Beerrsquos law in the range 00ndash13 120583gmLminus1 of tin with molar absorptivity and Sandellrsquos sensitivity of581times10

4 Lmolminus1 cmminus1 and 00020 120583g Sn cmminus2 respectively at 435 nmThemethod is highly selective and free from the interferenceof a large number of elements including platinum metals The ratio of metal to ligand in the extracted species is 1 2 Utilizing thismethod the analysis of various synthetic and technical samples including gunmetal and tin can have been carried out satisfactorily

1 Introduction

Tin does not occur free in nature and is found almostexclusively as tin oxide known as cassiterite or tin stoneTin although a toxic metal still it is being widely employedin manufacturing important alloys [1] and as solders forthe joining of electronic components The excess use oftin in daily life as fungicides in crops in food packagingand as stabilizer for polyvinyl chloride may introduce theinorganic tin Sn(II) and Sn(IV) in the environment Outof these two Sn(II) seems to be more toxic as compared toSn(IV) [2] In the literature there are numerous analyticalmethods for the measurement of tin which are based onsophisticated instruments [3ndash10] These methods are highlysensitive but generally tedious and prone to serious interfer-ences from other elements In contrast spectrophotometricmethods are preferred due to their simplicity and speed inroutine analysisThe reported studies have shown that a largenumber of reagents such as methyl orange [11] benzopyranderivatives [1 12 13] 2-(5-nitro-2-pyrilazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino-phenoyl] [14] pyrocatechol violet

[15ndash18] phenylfluorone [19 20] dibromohydroxyphenylflu-orone [21] arsenazo-M [22] isoamyl xanthate [23] diacetyl-monoxime-p-hydroxybenzoyl-hydrazine [24] bromopyro-gallol red [25] potassium ethylxanthate [26] ferron [27] and57-dichloro-8-quinolinol [28] have been used for the spec-trophotometric determination of tin(IIIV) content Amongthese many reagents [18 21 23 26ndash28] are nonselective asthey suffer from the interference have low sensitivity [11 1223 24 26ndash28] and some of them are time consuming as theyrequire time for full color development [14 18 20] Some ofthe sensitive reagents [16 17 21 22 25] are reported but theserequire the use of the surfactants plasticizer and critical pHadjustment Thus in the view of the above facts it reveals thatthere is still a lot of scope for working out new methods andeffecting amendments in the existing ones especially becauseof their lower sensitivity and selectivity Keeping in mind thescope of the reported facts a chromone derivative 6-chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzopyran(CHTB) hasbeen used for complexation and spectrophotometric deter-mination of trace amount of tin(II) The reagent 6-chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzopyran was found

Hindawi Publishing CorporationAdvances in ChemistryVolume 2014 Article ID 750973 6 pageshttpdxdoiorg1011552014750973

2 Advances in Chemistry

to give a sensitive reaction with Sn(II) In the present com-munication optimization of conditions for the quantitativeextraction of Sn(II)-CHTB complex was worked out apartfrom the studies involving stoichiometry and Beerrsquos lawrange determinationThe interference studies for diverse ionswere also carried out and the extraction of Sn(II)-CHTBwas made free from interference of large number of metalions by using suitable masking agents The extraction ofthe Sn(II)-CHTB complex into dichloromethane forms thebasis of the proposedmethod which provides the advantagesparticularly in respect of sensitivity selectivity and colordevelopment time to the existing methods Some syntheticand technical samples including gun metal and tin can havebeen analyzed for tin contents with good agreement

2 Experimental

21 Apparatus A model-140-02 Shimadzu with 10mmmatched cells was used for the routine absorbance measure-ments and spectral studies

22 Reagents and Solutions The standard stock solution(250mL) of Sn(II) containing 1mgmLminus1 of the metal ionwas prepared by dissolving an accurately weighed amount(0475 g) of SnCl

2sdot2H2O (RANBAXY) in 20mL of concen-

trated hydrochloric acid diluting with deionized water up tothe mark and standardized by the SnO

2method gravimetri-

cally [29] Lower concentration at 120583gmLminus1 level was preparedby suitable dilution of this solution containing 05mol Lminus1HCl final acidity The containers of the tin solution werewrapped with carbon paper and kept in dark place Stocksolutions of other metal ions were prepared at mg mLminus1 levelby dissolving their sodium or potassium salts in deionizedwater or dilute acid They were suitably diluted to give120583gmLminus1 level concentration of the metal ions

6-Chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzo-pyran (CHTB mp 200ndash202∘C) was synthesized by theliterature method [30] and dissolved in acetone to give01 (mv) solution The chemical composition of CHTB isC13H7O3SCl and its structure is given in Figure 4

Dichloromethane (Ranbaxy) was used for extraction assuch

23The Samples Synthetic samples were prepared bymixingtin solution with solutions of various metal ions in suitableproportions so as to give the composition as shown in Table 1

24 Gun Metal A weighed sample of gun metal (02 g) wasdissolved in 10mL of concentrated hydrochloric acid and 2ndash4mL of concentrated nitric acid on heating and the volumewas made up to 100mL in a volumetric flask 10ML of thissolution was diluted to 100mL to get a working solution oflow concentration An aliquot (025mL) of this solution wasanalyzed by the proposed method

25 Tin Can A weighed sample (06 g) of tin taken in a10mL beaker was heated gently with 5mL of concentrated

Table 1The analysis of various samples with the proposed method

Sample compositionMatrixlowast Sn added 120583g Sn foundlowastlowast 120583gZn(002) Pb(001) Cu(0001)a 100 1003 plusmn 085Cu(0070) Co(0014)b 80 789 plusmn 071Co(1) Ba(2) U(001) Mo(0020)c 70 683 plusmn 058Cd(2) Fe(01) V(01)d 120 1196 plusmn 071Cr(01) Sr(1) Ag(05) Zr(001)e 120 1199 plusmn 062Pb (2) Nb(01) Th(005) f 50 513 plusmn 163As(2) Se(3) Ti(01)e 80 792 plusmn 056Re(001) Ta(005) Bi(1)g 50 503 plusmn 082Be(2) Pt(001) Ir(001) 100 985 plusmn 041Gun metal 49h 448 plusmn 072Tin can mdash 015i

lowastAmount of metal ion shown in parentheses is in mg lowastlowastAverage oftriplicate analyses mean plusmn RSD abCorrespond to kneiss metal andargental respectively cIn presence of 05mg dithionite dIn presence of100mg ascorbic acid eIn presence of 7mg phosphate fIn presence of 4mgoxalate gIn presence of 100mg iodide hCertified value iConfirmed by SnO2method

hydrochloric acid The sample was dissolved completely byadding 5ndash10mL of distilled water and heating until thevolume was reduced to 2ndash5mL After cooling the volume ofthe solution was made up to 25mL and suitable portions ofthe sample solution were analyzed for tin content

26 Procedure To 1mL aliquot of the sample solution con-taining le13 120583g Sn(II) in 05mol Lminus1 hydrochloric acid wereadded 1mL of 6-chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzopyran (01 in acetone) solution and distilled waterto make the aqueous volume up to 10mL in a short stemmed125mL separating funnel The contents were mixed well andequilibrated with 10mL of dichloromethane for 20 sThe twolayers were allowed to separate and the yellow colored solventlayer was passed through Whatman filter paper (number 419 cm diameter) and collected into 10mL measuring flaskThe absorbance of the yellow complex was measured at435 nm against similarly treated reagent blank The standardcalibration curve was prepared by applying the procedure toa solution containing tin up to 13 120583g per 10mL of the aqueousvolumeThe tin contentswere computed from this calibrationcurve

Modifications of the method for V Fe Nb Zr W MoBi and Ti in the sample when Ti(IV) Zr(IV) and W(VI)were masked with sodium phosphate Fe(III) and V(V) withascorbic acid Bi(III) with potassium iodide Mo(VI) withsodium dithionite and Nb(V) with sodium oxalate addedprior to the addition of reagent and solvent The respectiveamount of the masking agents used was mentioned in theeffect of diverse ions

3 Results and Discussion

Tin(II) reacted with 6-chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzopyran(CHTB) in an acid medium to form

Advances in Chemistry 3

380 400 420 440 460 480

00

05

10

B

A

Abso

rban

ce

Wavelength (nm)

Figure 1 Absorption spectrum of Sn(II)-CHTB complex in dichlo-romethane Curve A 1 120583g SnmL measured against reagent blankCurve B reagent blank measured against dichloromethane

a yellow colored species which was quantitatively extractedinto dichloromethane The absorption spectrum of the col-ored Sn(II)-CHTB complex in dichloromethane indicatedthe maximum absorbance at 432ndash437 nm in the visibleregion where the reagent blank had hardly any absorbance(Figure 1) The effect of various parameters on the formationand absorbance of the complex are listed in Table 2

The absorbance of the complex was found maximum inHCl medium where as it was observed to be low in H

2SO4

CH3COOH and HClO

4 Since the Sn(II)-CHTB complex

showed maximum absorbance in 0046ndash005mol Lminus1 HClso 005mol Lminus1 HCl was chosen to provide suitable acidityPortions 05ndash22mL of 01 CHTB solution in acetoneresulting in maximum absorbance to the complex underall the conditions were stated in Table 1 and thus 1mLwas considered to be sufficient for the system Further thecomplex shows maximum absorbance when an equilibrationtime of up to 5min is kept therefore in order to save time20 s is considered to be the desired contact time for theextraction of the complex from the aqueous solution

Out of the number of the solvents studied for extraction ofthe Sn(II)-CHTB complex dichloromethane was found to bemost suitable because it provides a high absorbance value andstability of the complexThe absorbance showed a downwardtrend in the case of dichloromethane 12-dichloroethanebenzene toluene ethyl acetate carbon tetrachloride isoamylacetate isobutyl methyl ketone chloroform cyclohexaneand isoamyl alcohol So the dichloromethane was selected forthe extraction of the Sn(II)-CHTB complex from the aqueousphase

From a study of the above variables the optimum con-ditions for the system have been laid down as already statedin the procedure The metal complex obeys Beerrsquos law in therange 0ndash13 120583g Sn(II) mLminus1 However according to Ringbomplot [31] the optimum range for accurate determination of tinis 028ndash125 120583gmLminus1 Themolar absorptivity specific absorp-tivity and Sandellrsquos sensitivity of the complex at 435 nm are

Table 2 Effect of various parameters on the absorbance of Sn(II)-CHTB complex

HCla (M) 0043 0044 0045 0046ndash0060 0065Absorbance 0370 0420 0460 0490 0450CHTBb (mL) 02 03 04 05ndash22 25Absorbance 0310 0375 0440 0490 0430Equilibration timec(sec) 00 2 4 5ndash300 mdash

Absorbance 0100 0320 0480 0490 mdashConditions (a) Sn(II) = 10120583g HCl = variable CHTB (01 (mv) inacetone) = 1mL aqueous volume = solvent volume = 10mL solvent =dichloromethane equilibration time = 20 s 120582max = 435 nm (b) HCl =0046ndash0060mol Lminus1 other conditions being the same as in (a) except forthe variation in CHTB concentration also b = 6-chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzopyran (CHTB) and (c) 01 CHTB in acetone =1mL other conditions being the same as in (b) except for the variation inequilibration time

00 02 04 06 08 10

12

00

02

04

06

08

10

Mole fraction of Sn(II)

Abso

rban

ceA

B

C

Figure 2 Jobrsquos method of continuous variations of Sn(II) andCHTB Curve A435 nm Curve B 410 nm and Curve C 450 nm

581 times 104 Lmolminus1 cmminus1 0489mL gminus1 cmminus1 and 00020120583gSn(II) cmminus2 respectively The ratio of Sn(II) CHTB in theextracted species is determined using their equimolar solu-tion (8425 times 10minus4M) at three different wavelengths 410 435450 nm by Jobrsquos method (Figure 2) of continuous variationsas modified by Vosburgh and Cooper for a two-phase system[32 33] The sharp break in the curves indicates a metal-to-ligand ratio of 1 2 stoichiometry in the extracted speciesThisis further supported by the mole ratio method (Figure 3) [34]by taking the concentration of Sn(II) as 4218 times 10minus4M andmeasuring the absorbance again at three wavelengths 410435 450 nm The most probable structure of the Sn-CHTBcomplex is given as shown in Figure 5

31 Effect of Diverse Ions Under optimum conditions ofthe procedure the effect of different anions and cationshas been studied on the absorbance of the Sn(II)-CHTBcomplex The amount of diverse ions which caused a le1error in the absorbance was taken as the tolerance limit Thetolerance limit of foreign ions tested is given in Table 3 The


00

02

04

06

08

10

12

14

0 1 2 3 4 5

Mole ratio (CHTB Sn)

Abso

rban

ce

A

B

C

Figure 3 Mole ratio method of CHTB and Sn(II) Curve A435 nmCurve B 410 nm and Curve C450 nm

O

Cl

O

OH

S

Figure 4 Chemical Structure of CHTB

reported anions and cations did not influence the absorbanceof the Sn(II)-CHTB complex However fluoride interferedseriously even in traces The amount of sodium or potassiumsalts of the various anions were taken in mg while glyceroland H

2O2(30 mv) were taken in mL

Among the study of cations it was found that cations likeFe(III) Zr(IV) Nb(V) V(V) Mo(VI) W(VI) and Ti(IV)did influence the absorbance of the Sn(II)-CHTB complexHowever the interference of these metals could be preventedby making use of suitable masking agents that is for 1mg ofFe(III) 100mg ascorbic acid for 1mg of Nb(V) 4mg sodiumoxalate for 1mg of V(V) 100mg ascorbic acid for 01mgof Mo(VI) 5mg of sodium dithionite for 1mg of W(VI)7mg sodium phosphate for 15mg Zr(IV) 7mg sodiumphosphate for 03mg of Ti(IV) 7mg sodium phosphate andfor 5mg of Bi(III) 100mg iodide added prior to the additionofCHTB in 10mL aqueous volumeunder optimumconditionof the procedure

4 Conclusion

For the determination of microamounts of tin the proposedmethod is simple rapid sensitive and selective and freefrom the interference of a large number of metal ions Thewide applicability of the method is tested by the analysis ofseveral synthetic samples tin can and gunmetal sample with

O

S

Cl

O

OO

Cl

O

O

S

Sn

Figure 5 Chemical Structure of Sn(II)-CHTB complex

Table 3 Tolerance limit of different ions in the determination of10 120583g of Sn(II)

Ions Tolerance limit(concentration mg10mL)

Thiourea sulphite ascorbic acidand iodide 1000

Sulphate nitrate 800Bromide sulfosalicylic acid 750Chloride tartrate 500Acetate 400Carbonate citrate 200Thiocyanate 100Phosphate 70Dithionite 50Oxalate 40EDTA ldquodisodium saltrdquo 20Glycerol 10a

H2O2 (30 mv) 05a

Zn(II) Pb(II) and Se(II) 100Cd(II) 80Ba(II) Ni(II) Co(II) and Hg(II) 50Be(II) Ce(IV) As(II) Mg(II)Mn(II) Sr(II) Al(III) and Os(VIII) 30

Ag(I) Cu(II) 20U(VI) 10Ta(V) 07Cr(VI) 05Th(IV) 03Ru(III) Ir(III) 01aValue given in mL

satisfactory results The high reproducibility of the methodis tested by performing several sets of experiments whilekeeping the same amount of tin metal ions in each set therelative standard deviation of the method is 098


Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authorsrsquo sincere thanks are due to Kurukshetra Uni-versity Kurukshetra and Panjab University Chandigarh forproviding the necessary facilities

References

[1] R Kataria H K Sharma N Agnihotri and J R Mehta ldquo2-(21015840-Furyl)-3-hydroxy-4-oxo-4H-1-benzopyran as a highly selectiveand sensitive reagent for spectrophotometric determination oftin(II)rdquo Proceedings of the National Academy of Sciences of Indiavol 78 pp 31ndash35 2008

[2] TMadrakianAAfkhami RMoein andMBahram ldquoSimulta-neous spectrophotometric determination of Sn(II) and Sn(IV)by mean centering of ratio kinetic profiles and partial leastsquares methodsrdquo Talanta vol 72 no 5 pp 1847ndash1852 2007

[3] C Prior andG SWalker ldquoThe use of the bismuth film electrodefor the anodic stripping voltammetric determination of tinrdquoElectroanalysis vol 18 no 8 pp 823ndash829 2006

[4] Y Mino ldquoDetermination of tin in canned foods by X-rayfluorescence spectrometryrdquo Journal of Health Science vol 52no 1 pp 67ndash72 2006

[5] J-B Liu and Y-Z Wu ldquoRapid determination of tin in ore byatomic emission spectrometryrdquo Yejin Fenxi vol 33 no 3 pp65ndash68 2013

[6] Y Lin ldquoDetermination of tin in canned food with hydride-atomic fluorescence spectrometryrdquo Fenxi Ceshi Jishu Yu Yigivol 19 pp 149ndash152 2013

[7] Y Yu Z-Y He Z-C Mao et al ldquoDetermination of tin in byspectral lines with different sensitivity of alternating currentarc emission spectroscopyrdquo Yankuang Ceshi vol 32 pp 44ndash472013

[8] L Prusa J Dedina and J Kratzer ldquoUltratrace determinationof tin by hydride generation in-atomizer trapping atomicabsorption spectrometryrdquo Analytica Chimica Acta vol 804 pp50ndash58 2013

[9] S V de Azevedo F R Moreira and R C Campos ldquoDirectdetermination of tin in whole blood and urine by GF AASrdquoClinical Biochemistry vol 46 no 1-2 pp 123ndash127 2013

[10] I Trandafir V Nour andM E Ionica ldquoDetermination of tin incanned foods by inductively coupled plasma-mass spectrome-tryrdquo Polish Journal of Environmental Studies vol 21 no 3 pp749ndash754 2012

[11] X-LWang P Zhang and Y Chen ldquoSpectrophotometric deter-mination of stannum in copper alloy based on fading reactionof methyl orangerdquo Yejin Fenxi vol 32 no 12 pp 73ndash75 2012

[12] R Kataria and H K Sharma ldquo3-Hydroxy-2-[11015840-phenyl-31015840-(410158401015840-methoxyphenyl)-41015840-pyrazoyl]-4-oxo-4H-1-benzopyran asa spectrophotometric reagent for the micro-determination oftinrdquo Journal of the Indian Chemical Society vol 89 no 1 pp121ndash126 2012

[13] R Kataria andHK Sharma ldquoAn extractive spectrophotometricdetermination of tin as Sn(II)-6-chloro-3-hydroxy-7-methyl-2-(41015840-methoxyphenyl)-4-oxo-4H-1-benzopyran complex into

dichloromethanerdquo Eurasian Journal of Analytical Chemistryvol 6 no 3 pp 140ndash149 2011

[14] B Chen Q Zhang H Minami M Uto and S Inoue ldquoSpec-trophotometric determination of tin in steels with 2-(5-nitro-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenolrdquo Analytical Letters vol 33 no 14 pp 2951ndash2961 2000

[15] J-H Tang L-H Cheng and X-M Wu ldquoPyrocatechol violet-CPB spctrophotometric Determination of tin in copper alloysrdquoGuangpu Shiyanshi vol 30 pp 1925ndash1928 2013

[16] M Abbasi-Tarighat ldquoKinetic-spctrophotometric Determina-tion of tin species using feed-forward neural network and radialbasis function network in water and juices of canned fruitsrdquoAnalytical Chemistry vol 12 pp 256ndash263 2013

[17] T Madrakian and F Ghazizadeh ldquoMicelle-mediated extractionand determination of tin in soft drink and water samplesrdquoJournal of the Brazilian Chemical Society vol 20 no 8 pp 1535ndash1540 2009

[18] A C S Costa L S G Teixeira and S L C Ferreira ldquoSpec-trophotometric determination of tin in copper-based alloysusing pyrocatechol violetrdquoTalanta vol 42 no 12 pp 1973ndash19781995

[19] P Huang ldquoSpectrophotometric determination of tin in anti-mony materials by using phenylfluronerdquo Hunan Youse Jinshuvol 29 pp 68ndash79 2013

[20] D-X Wang F Chen and Z-F Liu ldquoSpectrophotometricdetermination of tin in flot glassrdquoTheAmerican Ceramic SocietyBulletin vol 84 no 12 pp 9401ndash9404 2005

[21] H Yan ldquoSpectrophotometric determination of tin in steel withdibromo-hydroxyphenylfluoronerdquoYejin Fenxi vol 23 no 6 pp45ndash46 2003

[22] C Cai Z Zhou S Chen and Y Fang ldquoResearch progress oftannery wastewater treatmentrdquo Applied Mechanics and Materi-als vol 361ndash363 pp 666ndash669 2013

[23] S P Arya S C Bhatia A Bansal and M Mahajan ldquoIsoamylxanthate as a sensitive reagent for the spectrophotometricdetermination of tinrdquo Journal of the Indian Chemical Societyvol 79 no 4 pp 359ndash360 2002

[24] A Varghese and A M A Khadar ldquoHighly selective derivativespectrophotometric determination of tin (II) in alloy samplesin the presence of cetylpyridinium chloriderdquo Acta ChimicaSlovenica vol 53 no 3 pp 374ndash380 2006

[25] X Huang W Zhang S Han and X Wang ldquoDeterminationof tin in canned foods by UVvisible spectrophotometrictechnique using mixed surfactantsrdquo Talanta vol 44 no 5 pp817ndash822 1997

[26] S P Arya and A Bansal ldquoRapid and selective method forthe spectrophotometric determination of tin using potassiumethylxanthaterdquo Mikrochimica Acta vol 116 no 1ndash3 pp 63ndash711994

[27] S P Arya S C Bhatia and A Bansal ldquoExtractive-spectropho-tometric determination of tin as Sn(II)-ferron complexrdquo Frese-niusrsquo Journal of Analytical Chemistry vol 345 no 11 pp 679ndash682 1993

[28] A M Gutierrez M V Laorden A Sanz-Medel and J L NietoldquoSpectrophotometric determination of tin(IV) by extractionof the ternary tiniodide57-dichloro-8-quinolinol complexrdquoAnalytica Chimica Acta vol 184 no C pp 317ndash322 1986

[29] G H Jeffery J Bassett J Mendham and R C Denny VogelsTextbook of Quantitative Chemical Analysis Addison WesleyLongman Singapore 5th edition 1989


[30] S C Gupta N S Yadev and S N Dhawan ldquoSynthesis of 2 3diaryl 8 methyl 2 3 4 10 tetrahydropyrano 3 2 b 1 benzopyran10 ones photoisomerization of styrylchromonesrdquo Indian JournalOf Chemistry Section B Organic Chemistry Including MedicinalChemistry vol 30 no 2 pp 790ndash792 1991

[31] A Ringbom ldquoUber die Genauigkeit der colorimetrischenAnal-ysenmethoden Irdquo Fresenius Journal of Analytical Chemistry vol115 no 9ndash10 pp 332ndash343 1938

[32] P Job ldquoFormation and stability of inorganic complexes insolutionrdquo Annali di Chimica vol 9 pp 113ndash203 1928

[33] W C Vosburgh and G R Cooper ldquoComplex ions I Theidentification of complex ions in solution by spectrophoto-metric measurementsrdquo The Journal of the American ChemicalSociety vol 63 no 2 pp 437ndash442 1941

[34] J H Yoe and A L Jones ldquoColorimetric determination of ironwith disodium-12-dihydroxybenzene-35-disulfonaterdquo Indus-trial amp Engineering Chemistry Analytical Edition vol 16 no 2pp 111ndash115 1944

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


to give a sensitive reaction with Sn(II) In the present com-munication optimization of conditions for the quantitativeextraction of Sn(II)-CHTB complex was worked out apartfrom the studies involving stoichiometry and Beerrsquos lawrange determinationThe interference studies for diverse ionswere also carried out and the extraction of Sn(II)-CHTBwas made free from interference of large number of metalions by using suitable masking agents The extraction ofthe Sn(II)-CHTB complex into dichloromethane forms thebasis of the proposedmethod which provides the advantagesparticularly in respect of sensitivity selectivity and colordevelopment time to the existing methods Some syntheticand technical samples including gun metal and tin can havebeen analyzed for tin contents with good agreement

2 Experimental

21 Apparatus A model-140-02 Shimadzu with 10mmmatched cells was used for the routine absorbance measure-ments and spectral studies

22 Reagents and Solutions The standard stock solution(250mL) of Sn(II) containing 1mgmLminus1 of the metal ionwas prepared by dissolving an accurately weighed amount(0475 g) of SnCl

2sdot2H2O (RANBAXY) in 20mL of concen-

trated hydrochloric acid diluting with deionized water up tothe mark and standardized by the SnO

2method gravimetri-

cally [29] Lower concentration at 120583gmLminus1 level was preparedby suitable dilution of this solution containing 05mol Lminus1HCl final acidity The containers of the tin solution werewrapped with carbon paper and kept in dark place Stocksolutions of other metal ions were prepared at mg mLminus1 levelby dissolving their sodium or potassium salts in deionizedwater or dilute acid They were suitably diluted to give120583gmLminus1 level concentration of the metal ions

6-Chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzo-pyran (CHTB mp 200ndash202∘C) was synthesized by theliterature method [30] and dissolved in acetone to give01 (mv) solution The chemical composition of CHTB isC13H7O3SCl and its structure is given in Figure 4

Dichloromethane (Ranbaxy) was used for extraction assuch

23The Samples Synthetic samples were prepared bymixingtin solution with solutions of various metal ions in suitableproportions so as to give the composition as shown in Table 1

24 Gun Metal A weighed sample of gun metal (02 g) wasdissolved in 10mL of concentrated hydrochloric acid and 2ndash4mL of concentrated nitric acid on heating and the volumewas made up to 100mL in a volumetric flask 10ML of thissolution was diluted to 100mL to get a working solution oflow concentration An aliquot (025mL) of this solution wasanalyzed by the proposed method

25 Tin Can A weighed sample (06 g) of tin taken in a10mL beaker was heated gently with 5mL of concentrated

Table 1The analysis of various samples with the proposed method

Sample compositionMatrixlowast Sn added 120583g Sn foundlowastlowast 120583gZn(002) Pb(001) Cu(0001)a 100 1003 plusmn 085Cu(0070) Co(0014)b 80 789 plusmn 071Co(1) Ba(2) U(001) Mo(0020)c 70 683 plusmn 058Cd(2) Fe(01) V(01)d 120 1196 plusmn 071Cr(01) Sr(1) Ag(05) Zr(001)e 120 1199 plusmn 062Pb (2) Nb(01) Th(005) f 50 513 plusmn 163As(2) Se(3) Ti(01)e 80 792 plusmn 056Re(001) Ta(005) Bi(1)g 50 503 plusmn 082Be(2) Pt(001) Ir(001) 100 985 plusmn 041Gun metal 49h 448 plusmn 072Tin can mdash 015i

lowastAmount of metal ion shown in parentheses is in mg lowastlowastAverage oftriplicate analyses mean plusmn RSD abCorrespond to kneiss metal andargental respectively cIn presence of 05mg dithionite dIn presence of100mg ascorbic acid eIn presence of 7mg phosphate fIn presence of 4mgoxalate gIn presence of 100mg iodide hCertified value iConfirmed by SnO2method

hydrochloric acid The sample was dissolved completely byadding 5ndash10mL of distilled water and heating until thevolume was reduced to 2ndash5mL After cooling the volume ofthe solution was made up to 25mL and suitable portions ofthe sample solution were analyzed for tin content

26 Procedure To 1mL aliquot of the sample solution con-taining le13 120583g Sn(II) in 05mol Lminus1 hydrochloric acid wereadded 1mL of 6-chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzopyran (01 in acetone) solution and distilled waterto make the aqueous volume up to 10mL in a short stemmed125mL separating funnel The contents were mixed well andequilibrated with 10mL of dichloromethane for 20 sThe twolayers were allowed to separate and the yellow colored solventlayer was passed through Whatman filter paper (number 419 cm diameter) and collected into 10mL measuring flaskThe absorbance of the yellow complex was measured at435 nm against similarly treated reagent blank The standardcalibration curve was prepared by applying the procedure toa solution containing tin up to 13 120583g per 10mL of the aqueousvolumeThe tin contentswere computed from this calibrationcurve

Modifications of the method for V Fe Nb Zr W MoBi and Ti in the sample when Ti(IV) Zr(IV) and W(VI)were masked with sodium phosphate Fe(III) and V(V) withascorbic acid Bi(III) with potassium iodide Mo(VI) withsodium dithionite and Nb(V) with sodium oxalate addedprior to the addition of reagent and solvent The respectiveamount of the masking agents used was mentioned in theeffect of diverse ions

3 Results and Discussion

Tin(II) reacted with 6-chloro-3-hydroxy-2-(21015840-thienyl)-4-oxo-4H-1-benzopyran(CHTB) in an acid medium to form


380 400 420 440 460 480

00

05

10

B

A

Abso

rban

ce

Wavelength (nm)




2SO4

CH3COOH and HClO








00 02 04 06 08 10

12

00

02

04

06

08

10


Abso

rban

ceA

B

C





00

02

04

06

08

10

12

14

0 1 2 3 4 5


Abso

rban

ce

A

B

C


O

Cl

O

OH

S





4 Conclusion


O

S

Cl

O

OO

Cl

O

O

S

Sn






H2O2 (30 mv) 05a







Acknowledgments


References














































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


380 400 420 440 460 480

00

05

10

B

A

Abso

rban

ce

Wavelength (nm)




2SO4

CH3COOH and HClO








00 02 04 06 08 10

12

00

02

04

06

08

10


Abso

rban

ceA

B

C





00

02

04

06

08

10

12

14

0 1 2 3 4 5


Abso

rban

ce

A

B

C


O

Cl

O

OH

S





4 Conclusion


O

S

Cl

O

OO

Cl

O

O

S

Sn






H2O2 (30 mv) 05a







Acknowledgments


References














































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


00

02

04

06

08

10

12

14

0 1 2 3 4 5


Abso

rban

ce

A

B

C


O

Cl

O

OH

S





4 Conclusion


O

S

Cl

O

OO

Cl

O

O

S

Sn






H2O2 (30 mv) 05a







Acknowledgments


References














































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




Acknowledgments


References














































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of
















Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

a rapid extractive spectrophotometric method for the determination

Documents