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Absorptiometric determination of palladium with 2,3-quinoxalinedithiol
Short communiations
1190
REFERENCES 1. E. B. Sandell, Cokwimetr& Determinat&n of Traces of Metah, 3rd Ed., Itttendcarce, New York, 1959. 2. A. I. Busev. V. B. Byrko and I. I. Grandberg, Vestn. Moskoe. Univ. Ber. II, 1960,15, NO. 2.76. 3. A. I. Busev. Fang Chang and Z. P. Kuayaeva, Zh. Analit. Khim., 1%1,16,695. 4. J.Bankmdi, E. Svams and A. Lovhut, ibid., 1959,14,313. 5. A. L Busev and Fang Chan , ibid, 1961,16,39. 6. J. B. Binglay, J. Agr. Food !hun ., 1959,7,269. 7. I-I.Buss, II. W. Kohlschuttar and S. Madtank, 2. Anal. Ch, 1960,17&l. 8. G. B&r and G. Schloitzor, Ber., 1957,90,438. 9. A. Davison and R. H. Hahn, Inorg. Synth., 1%7,10,11.
Chem. Sot., 1950,72,4438;
1952,74,4744.
T&ham 1972.vol. 19,pp. 1199to 1193. Rmmom.hRhw3LnNarUmmInM
(Received 20 December 1971. Accepted 12 January 1972) Tna ORDINAL MBIRM)II haveuaedawa
EXPERIMENTAL A O-1% w/v solution of mqt, prepared amm&um
chloride and O-6g of zinc &hate
Proceabre
To 1 ml of the &c-but& sohrtion in a loo-ml boakar add 5 ml of the 0-l % reagent solution followed by a suitable rl’ uot of the aampla solution (Note8 1 and 2). Dihtta to 25 ml with water and zieag&ybath (2 ) for about 5 min. Cool and dilate with water to 50 mi in a standard tlask. brortwurcsat’454 nm in a l-cm cell against the reagent blank, prepamd m the same way, and read the cmmmttation ofpalhdmm from a calibration Notes 1. The sample ls chosen to provide between 4 anrp” 125 pg of palladium in the final 50-ml solution. 2. To suppmss the hydroiysis of ions such as FoI+, Al’+ and &In’+5 mi of 5% aqueous ammonium citrate solution can be added here.
Short commuuicatious
1191
RESULTS Pr&nhary imestigation AcMith~~of t to alkaline solutioas of paIladium(II) results in the formation of a bright soluble complexm! ( -Du 454 mu, Fig. 1). Full colour development ocws after heat& the sozzz on a steam-bath (60”) for about 5 min. or afkerabout 1 hr at room , but more rapidly in the presence of a large excess of the reagent. No change in the a cewasobservedoverthe pH tauge 85-1@8, but at pH below 8.5 the solutions darkened and became cloudy. Ammouium chloride-ammouia butfer (pH 10) is suitable for the development of the colour. korporation of zinc in the but&r solution does not hinder the development of the colour, unless used in large excess. In the presence of zinc the st#iitks of the coloured and blank solutioas are markedly improved; abrarbpwcs remalu constant for more than a day and blanks are about 001 absorbance unit. Variationoh~ethaaolcantentoftherolutionshnsnoeffictonthe~colowbuttberateofformatian of the complex is slower when more ethanol is present. ComjWMonof the@Bdfwn+l c@Wp& The yellow complex is readily sorbed on auion-exchange resin and precipitated from solut@ by the add&kmof tetraphulyhuWmium chlortde. Elemetstai aualysts of tba cotqlex pr&lgitated m this wa andmcqsW@dfromohloroformgave: C,61.1%; I&3.%%; N,4*5%; &l&2/.; Pd.8.40/, i(&I,)&),~d(C,H,NsSs)~ requims: C, 61.2%; H, 443%; N, 4.4%; S, 10.5%; Pd. 83% The composition of the solution, obtained by the mole-ratio method.’ also indicated 1 a:1 t the aohmic (w(qdt)sP- is the ababing ofshnilarcomplexesofual hasbeenreWrtedbvLatbam’ _ * z/z . aitd StevanWiC and &WC?’
Mvslength, nm Fro. l.-Spectra of complexes of 2,3quinoxahh~ dithiol. Curve A-75 x 10-W reagent with excess of G&II) preseut. Curve R-29 ppm of paUadhsm(I1)with excess of reagent present. Rothspectmin8~aqueousethanolatpH1O. TABLEI.-hCISION
OF REIUMR
WlTH
PRoclBluRB
o-49 0.99 1.48 1.98 2.47
FOR
S-2f%dRRC~) PALLADIUM Maui
palladium. mm
TRR
THIURONlUM (10
CUUMIDR
VARUTRS) sadiud
R&&e
st~ndmd
absorbance
deviation
deviation of mean, %
0911+014 O%l-M64
OM2 0.063
OGOl 0.W
3.6 0.5
0*154+157 O-308+317 0.4614468 0612-0.621 0.772-0.780
0.155 0.312 K45
0.001 0.002 0.003 0.003 0903
g:: 0.2 0.2 0.1
A_rPnge
0.776
Short communications
1192 Sensitivity and precision
Beer% law is obvycd. in the rccommendcd pr c&&ration graph pmpanxi from the results given m origin. Tha Sandall !BEnsitivityhldax for tho reaction ls 454 nm b 3.30 x 1tY1. mole-l. mm-‘. Tha mathod is shownbythepra&&mofthercaultsgivaninTablaI.
HPO)-, ClO,-, SCN- and S,O,‘-) nor from the alkali and w Errors of about 1% am caused bv UIJto lOO-fold amounts of the followinn snacks: A&?. La(IIIL Mo(VI), Th(IV), +j(IV), V(V) arid ti(VI). This is also the situation for h&II), Cr(IIIj,~$e@) ii citratelsadd&topreventhy&&yslR EDTAlntB&ra!4,prmaa&& MIl(lI)providCdth8t-
and tha elamsnts CONCLUSION The trend in the developmentof new methods is the attainmwptof higher sensitivity and.selaztivlty, led with the uso of q&k, sim It proccdurm capable of automation. A ~~o~mcthodrforpp&lumhas~givmby~~’ Thcxs to data is the absoxptiomctk procedure of et al.,* who utilize the formationsf a ternary cow of palladium with pyridine and Rosa Extra (4 = 1.2s x l(r l.mole”.mm-X). This DaEz ~~~uhxa a solvent-extraction procedum. #z uscrulnasofthemqtmathodmaybathat lax is soluble in water, it is simphx and mom rapid, and has vary high precision. The sensitivity ““po the deacrilxd method, although lower, compares favourably with thoos of w absorptiomctric mathods. Ac&nowie@meiu$-wo acknowledge with gratitude tha &nt of study kave from Klagston PolytachnlctoA.K.S.,andwethaukMr.S.Attardforchcc gsomeofthercsults. J. A, W. DAL~JHL A. K Stiwms~~* Deparment of Chemimy Cheha College of Science and Technohgy Monresa Road, Lon&wa, S.W.3
F-j-Amethodisdascribcdforthea
pakknn@) and (qdtF* is lixmed at pH 10, having maximum absorbanu? at 454 mn and Sandall masitivitv index of m32 u&m*. The reaction is moderately salactive; &alent ConcantratioEs of latinum0, iridium(IV) and rhodium(7II ) can be tokrated but go1B(III), copper0 and a few other metals interfere. Suggestions am made for masking interferenarr. The method is characterized by good precision, with a relative standard deviation of 0.25 % at the I-ppm level. l Present address: School of Chunkal Science and Technology, Kingston Polytechnic, Kingston upon Thames, Surrey, U.K.
1193 BEin Verfabrcn zur absorptiometrischen Bcstimmung van Palladium im Be&h 0.1-25 ppm mit wdithiol (Hqdt) in wHBrigemAt&an01wkd angegeban.m hpns s-2(3-Mucapto&inoxalioyl)thiuro&mchlorid (mqt) wird bet pH l0 ms& zu (qdt)* hydrolysicrt. In Gcgcnwart van Zink wird (qdt)‘dwch Kompl&Mung star; damit wrden die Blindfast &ufNul1vc&gcrt. Einaruonuohcr 1:2+K~~~~~~ und (q&t)” b&M sich bci pH 10, mit gr68tcr tmd dun Empfiad&&keMndcx nach Sandcll van 0,0032 @cm’. Die Reaktion ist m88ig wlektiv; 8quivalente Konzcnti van PlatinGold(m), Kupfer(IV), Iridi&IV) und Rhodium(III) sind ug; oundeiDigeandcreMtalicstorell. Eswerdcnvorschl@Imr Maerung der stwmgcn gemacht. Das verfahren &clmet sidl dtachhohe&nauigkeitaus: imlppm-Bcreichbctr8gtdierelatiw Stand&abweicbwg 02 ‘/, RLnrb-<)nd6aitlmcm6thodcpourlc dpztsl8doayiasO,1-2$~avcc L8r6actif~&lo?uN! ?H#)cn6th8nolaqwuz quiwmiinyl) thiouconiwn (mqt, at hydrol pH 10. En la prdsooce de zinc, (qdt)‘‘82.6ro. Un coJupkwctlest&n&lsdcsr6actifssolltr6duits compiexeani&que1:2dup&ladium(II)a& qdt)‘-c&f&i p”“4” HlO,etifrWIlkabsolption~B454mnetrmiadics&Isasi!ilit 6 sandell de 0.0032 &xn*. La r&actioncst mt s&&e, de3 consentrations uivakntes de plati.r@V), iridium(IV) et rhadium(III) peuvent$t, t016r&s, mais ror(III), k cuivrc(II), et quclqucs autns m6taux intsrftrent. On pr&cnte dcs suggestions pour . .
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
REFERENCES R W. Bwko and J. H. Yoe, A&. Chen., 1%2,34,1378. 0. H. Avms and R R Annmd. ibid.. 1963.3533. 0. H. A~TCS and R W. F&C&y, Ibid, 1964,i6,133. C3.H. Ayna and R. F. Jawta, i&&f.,1959.31,1985. J. A. W. DalzM and A. IL !%w.inski,T-a, 1968, IS, 367. Idem, ibid, 1%8,%, 1385. W. F. Hi&brand, 8. B. F. Iamddl, H. A. Bright and J. I. Hoffman, AppliedInoF& Analysis, 2nd Ed., Wiley, New York, 1953. J. H. Yoc and A. L. Jones. Zm! &. Gem., Anal.Ed., 1944,16,111. A. R Latham, Ph.D. lkb, The Rock&&r Uniwsity, New York, N.Y., 1966. D. B. Stcva&vid and V. 0. D&i&. Bull. Inst.NuckarSci. “BorisKi&ich”, BeIlgrodr, 1959.9, 69. S. Arhland, J. Chatt and E. R Davies, Qumr. Rev., 1958,l2,265. F. E. Beamish, T4h11)0,1965,l&743. R W. Dagnall, M. T. EGohamry and T. S. West. f&d..,1968,l5,1353.
labma,
197& vol. 19. pp. 1193 to 1199. PorrrmmRar
Determination of molybd-
RintcdiaNonbem-
by atombabsorption qedropMome!try
(Received12 Novetnber 1971. Accepted12 Jamuzry1972) METHOXM available for determination of molybduxum by atomic&so tion spc&opMometry involve the use of both nitrous oxideacctykr~~ and air-acatylcne tlamcs. ?be advantaguofusinga nitrous oxide-acctykw flame have bcc~ stressed by Willisf Methods involving the use of such a
1190
REFERENCES 1. E. B. Sandell, Cokwimetr& Determinat&n of Traces of Metah, 3rd Ed., Itttendcarce, New York, 1959. 2. A. I. Busev. V. B. Byrko and I. I. Grandberg, Vestn. Moskoe. Univ. Ber. II, 1960,15, NO. 2.76. 3. A. I. Busev. Fang Chang and Z. P. Kuayaeva, Zh. Analit. Khim., 1%1,16,695. 4. J.Bankmdi, E. Svams and A. Lovhut, ibid., 1959,14,313. 5. A. L Busev and Fang Chan , ibid, 1961,16,39. 6. J. B. Binglay, J. Agr. Food !hun ., 1959,7,269. 7. I-I.Buss, II. W. Kohlschuttar and S. Madtank, 2. Anal. Ch, 1960,17&l. 8. G. B&r and G. Schloitzor, Ber., 1957,90,438. 9. A. Davison and R. H. Hahn, Inorg. Synth., 1%7,10,11.
Chem. Sot., 1950,72,4438;
1952,74,4744.
T&ham 1972.vol. 19,pp. 1199to 1193. Rmmom.hRhw3LnNarUmmInM
(Received 20 December 1971. Accepted 12 January 1972) Tna ORDINAL MBIRM)II haveuaedawa
EXPERIMENTAL A O-1% w/v solution of mqt, prepared amm&um
chloride and O-6g of zinc &hate
Proceabre
To 1 ml of the &c-but& sohrtion in a loo-ml boakar add 5 ml of the 0-l % reagent solution followed by a suitable rl’ uot of the aampla solution (Note8 1 and 2). Dihtta to 25 ml with water and zieag&ybath (2 ) for about 5 min. Cool and dilate with water to 50 mi in a standard tlask. brortwurcsat’454 nm in a l-cm cell against the reagent blank, prepamd m the same way, and read the cmmmttation ofpalhdmm from a calibration Notes 1. The sample ls chosen to provide between 4 anrp” 125 pg of palladium in the final 50-ml solution. 2. To suppmss the hydroiysis of ions such as FoI+, Al’+ and &In’+5 mi of 5% aqueous ammonium citrate solution can be added here.
Short commuuicatious
1191
RESULTS Pr&nhary imestigation AcMith~~of t to alkaline solutioas of paIladium(II) results in the formation of a bright soluble complexm! ( -Du 454 mu, Fig. 1). Full colour development ocws after heat& the sozzz on a steam-bath (60”) for about 5 min. or afkerabout 1 hr at room , but more rapidly in the presence of a large excess of the reagent. No change in the a cewasobservedoverthe pH tauge 85-1@8, but at pH below 8.5 the solutions darkened and became cloudy. Ammouium chloride-ammouia butfer (pH 10) is suitable for the development of the colour. korporation of zinc in the but&r solution does not hinder the development of the colour, unless used in large excess. In the presence of zinc the st#iitks of the coloured and blank solutioas are markedly improved; abrarbpwcs remalu constant for more than a day and blanks are about 001 absorbance unit. Variationoh~ethaaolcantentoftherolutionshnsnoeffictonthe~colowbuttberateofformatian of the complex is slower when more ethanol is present. ComjWMonof the@Bdfwn+l c@Wp& The yellow complex is readily sorbed on auion-exchange resin and precipitated from solut@ by the add&kmof tetraphulyhuWmium chlortde. Elemetstai aualysts of tba cotqlex pr&lgitated m this wa andmcqsW@dfromohloroformgave: C,61.1%; I&3.%%; N,4*5%; &l&2/.; Pd.8.40/, i(&I,)&),~d(C,H,NsSs)~ requims: C, 61.2%; H, 443%; N, 4.4%; S, 10.5%; Pd. 83% The composition of the solution, obtained by the mole-ratio method.’ also indicated 1 a:1 t the aohmic (w(qdt)sP- is the ababing ofshnilarcomplexesofual hasbeenreWrtedbvLatbam’ _ * z/z . aitd StevanWiC and &WC?’
Mvslength, nm Fro. l.-Spectra of complexes of 2,3quinoxahh~ dithiol. Curve A-75 x 10-W reagent with excess of G&II) preseut. Curve R-29 ppm of paUadhsm(I1)with excess of reagent present. Rothspectmin8~aqueousethanolatpH1O. TABLEI.-hCISION
OF REIUMR
WlTH
PRoclBluRB
o-49 0.99 1.48 1.98 2.47
FOR
S-2f%dRRC~) PALLADIUM Maui
palladium. mm
TRR
THIURONlUM (10
CUUMIDR
VARUTRS) sadiud
R&&e
st~ndmd
absorbance
deviation
deviation of mean, %
0911+014 O%l-M64
OM2 0.063
OGOl 0.W
3.6 0.5
0*154+157 O-308+317 0.4614468 0612-0.621 0.772-0.780
0.155 0.312 K45
0.001 0.002 0.003 0.003 0903
g:: 0.2 0.2 0.1
A_rPnge
0.776
Short communications
1192 Sensitivity and precision
Beer% law is obvycd. in the rccommendcd pr c&&ration graph pmpanxi from the results given m origin. Tha Sandall !BEnsitivityhldax for tho reaction ls 454 nm b 3.30 x 1tY1. mole-l. mm-‘. Tha mathod is shownbythepra&&mofthercaultsgivaninTablaI.
HPO)-, ClO,-, SCN- and S,O,‘-) nor from the alkali and w Errors of about 1% am caused bv UIJto lOO-fold amounts of the followinn snacks: A&?. La(IIIL Mo(VI), Th(IV), +j(IV), V(V) arid ti(VI). This is also the situation for h&II), Cr(IIIj,~$e@) ii citratelsadd&topreventhy&&yslR EDTAlntB&ra!4,prmaa&& MIl(lI)providCdth8t-
and tha elamsnts CONCLUSION The trend in the developmentof new methods is the attainmwptof higher sensitivity and.selaztivlty, led with the uso of q&k, sim It proccdurm capable of automation. A ~~o~mcthodrforpp&lumhas~givmby~~’ Thcxs to data is the absoxptiomctk procedure of et al.,* who utilize the formationsf a ternary cow of palladium with pyridine and Rosa Extra (4 = 1.2s x l(r l.mole”.mm-X). This DaEz ~~~uhxa a solvent-extraction procedum. #z uscrulnasofthemqtmathodmaybathat lax is soluble in water, it is simphx and mom rapid, and has vary high precision. The sensitivity ““po the deacrilxd method, although lower, compares favourably with thoos of w absorptiomctric mathods. Ac&nowie@meiu$-wo acknowledge with gratitude tha &nt of study kave from Klagston PolytachnlctoA.K.S.,andwethaukMr.S.Attardforchcc gsomeofthercsults. J. A, W. DAL~JHL A. K Stiwms~~* Deparment of Chemimy Cheha College of Science and Technohgy Monresa Road, Lon&wa, S.W.3
F-j-Amethodisdascribcdforthea
pakknn@) and (qdtF* is lixmed at pH 10, having maximum absorbanu? at 454 mn and Sandall masitivitv index of m32 u&m*. The reaction is moderately salactive; &alent ConcantratioEs of latinum0, iridium(IV) and rhodium(7II ) can be tokrated but go1B(III), copper0 and a few other metals interfere. Suggestions am made for masking interferenarr. The method is characterized by good precision, with a relative standard deviation of 0.25 % at the I-ppm level. l Present address: School of Chunkal Science and Technology, Kingston Polytechnic, Kingston upon Thames, Surrey, U.K.
1193 BEin Verfabrcn zur absorptiometrischen Bcstimmung van Palladium im Be&h 0.1-25 ppm mit wdithiol (Hqdt) in wHBrigemAt&an01wkd angegeban.m hpns s-2(3-Mucapto&inoxalioyl)thiuro&mchlorid (mqt) wird bet pH l0 ms& zu (qdt)* hydrolysicrt. In Gcgcnwart van Zink wird (qdt)‘dwch Kompl&Mung star; damit wrden die Blindfast &ufNul1vc&gcrt. Einaruonuohcr 1:2+K~~~~~~ und (q&t)” b&M sich bci pH 10, mit gr68tcr tmd dun Empfiad&&keMndcx nach Sandcll van 0,0032 @cm’. Die Reaktion ist m88ig wlektiv; 8quivalente Konzcnti van PlatinGold(m), Kupfer(IV), Iridi&IV) und Rhodium(III) sind ug; oundeiDigeandcreMtalicstorell. Eswerdcnvorschl@Imr Maerung der stwmgcn gemacht. Das verfahren &clmet sidl dtachhohe&nauigkeitaus: imlppm-Bcreichbctr8gtdierelatiw Stand&abweicbwg 02 ‘/, RLnrb-<)nd6aitlmcm6thodcpourlc dpztsl8doayiasO,1-2$~avcc L8r6actif~&lo?uN! ?H#)cn6th8nolaqwuz quiwmiinyl) thiouconiwn (mqt, at hydrol pH 10. En la prdsooce de zinc, (qdt)‘‘82.6ro. Un coJupkwctlest&n&lsdcsr6actifssolltr6duits compiexeani&que1:2dup&ladium(II)a& qdt)‘-c&f&i p”“4” HlO,etifrWIlkabsolption~B454mnetrmiadics&Isasi!ilit 6 sandell de 0.0032 &xn*. La r&actioncst mt s&&e, de3 consentrations uivakntes de plati.r@V), iridium(IV) et rhadium(III) peuvent$t, t016r&s, mais ror(III), k cuivrc(II), et quclqucs autns m6taux intsrftrent. On pr&cnte dcs suggestions pour . .
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
REFERENCES R W. Bwko and J. H. Yoe, A&. Chen., 1%2,34,1378. 0. H. Avms and R R Annmd. ibid.. 1963.3533. 0. H. A~TCS and R W. F&C&y, Ibid, 1964,i6,133. C3.H. Ayna and R. F. Jawta, i&&f.,1959.31,1985. J. A. W. DalzM and A. IL !%w.inski,T-a, 1968, IS, 367. Idem, ibid, 1%8,%, 1385. W. F. Hi&brand, 8. B. F. Iamddl, H. A. Bright and J. I. Hoffman, AppliedInoF& Analysis, 2nd Ed., Wiley, New York, 1953. J. H. Yoc and A. L. Jones. Zm! &. Gem., Anal.Ed., 1944,16,111. A. R Latham, Ph.D. lkb, The Rock&&r Uniwsity, New York, N.Y., 1966. D. B. Stcva&vid and V. 0. D&i&. Bull. Inst.NuckarSci. “BorisKi&ich”, BeIlgrodr, 1959.9, 69. S. Arhland, J. Chatt and E. R Davies, Qumr. Rev., 1958,l2,265. F. E. Beamish, T4h11)0,1965,l&743. R W. Dagnall, M. T. EGohamry and T. S. West. f&d..,1968,l5,1353.
labma,
197& vol. 19. pp. 1193 to 1199. PorrrmmRar
Determination of molybd-
RintcdiaNonbem-
by atombabsorption qedropMome!try
(Received12 Novetnber 1971. Accepted12 Jamuzry1972) METHOXM available for determination of molybduxum by atomic&so tion spc&opMometry involve the use of both nitrous oxideacctykr~~ and air-acatylcne tlamcs. ?be advantaguofusinga nitrous oxide-acctykw flame have bcc~ stressed by Willisf Methods involving the use of such a