Minimization of lead and copper interferences on spectrophotometric determination of cadmium using electrolytic deposition and ion-exchange in multi-commutation flow system

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dc.contributor.authorGomes Neto, José Anchieta [UNESP]
dc.contributor.authorOliveira, Adriana P [UNESP]
dc.contributor.authorFreshi, Gian P.G [UNESP]
dc.contributor.authorDakuzaku, Carolina S [UNESP]
dc.contributor.authorDe Moraes, Mercedes [UNESP]
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-27T11:20:12Z
dc.date.available2014-05-27T11:20:12Z
dc.date.issued2000-12-04
dc.description.abstractA new strategy for minimization of Cu2+ and Pb2+ interferences on the spectrophotometric determination of Cd2+ by the Malachite green (MG)-iodide reaction using electrolytic deposition of interfering species and solid phase extraction of Cd2+ in flow system is proposed. The electrolytic cell comprises two coiled Pt electrodes concentrically assembled. When the sample solution is electrolyzed in a mixed solution containing 5% (v/v) HNO3, 0.1% (v/v) H2SO4 and 0.5 M NaCl, Cu2+ is deposited as Cu on the cathode, Pb2+ is deposited as PbO2 on the anode while Cd2+ is kept in solution. After electrolysis, the remaining solution passes through an AG1-X8 resin (chloride form) packed minicolumn in which Cd2+ is extracted as CdCl4/2-. Electrolyte compositions, flow rates, timing, applied current, and electrolysis time was investigated. With 60 s electrolysis time, 0.25 A applied current, Pb2+ and Cu2+ levels up to 50 and 250 mg 1-1, respectively, can be tolerated without interference. For 90 s resin loading time, a linear relationship between absorbance and analyte concentration in the 5.00-50.0 μg Cd 1-1 range (r2 = 0.9996) is obtained. A throughput of 20 samples per h is achieved, corresponding to about 0.7 mg MG and 500 mg KI and 5 ml sample consumed per determination. The detection limit is 0.23 μg Cd 1-1. The accuracy was checked for cadmium determination in standard reference materials, vegetables and tap water. Results were in agreement with certified values of standard reference materials and with those obtained by graphite furnace atomic absorption spectrometry at 95% confidence level. The R.S.D. for plant digests and water containing 13.0 μg Cd 1-1 was 3.85% (n = 12). The recoveries of analyte spikes added to the water and vegetable samples ranged from 94 to 104%. (C) 2000 Elsevier Science B.V.en
dc.description.abstractA new strategy for minimization of Cu2+ and Pb2+ interferences on the spectrophotometric determination of Cd2+ by the Malachite green (MG)-iodide reaction using electrolytic deposition of interfering species and solid phase extraction of Cd2+ in flow system is proposed. The electrolytic cell comprises two coiled Pt electrodes concentrically assembled. When the sample solution is electrolyzed in a mixed solution containing 5% (v/v) HNO3, 0.1% (v/v) H2SO4 and 0.5 M NaCl, Cu2+ is deposited as Cu on the cathode, Pb2+ is deposited as PbO2 on the anode while Cd2+ is kept in solution. After electrolysis, the remaining solution passes through an AG1-X8 resin (chloride form) packed minicolumn in which Cd2+ is extracted as CdCl4 2-. Electrolyte compositions, flow rates, timing, applied current, and electrolysis time was investigated. With 60 s electrolysis time, 0.25 A applied current, Pb2+ and Cu2+ levels up to 50 and 250 mg l-1, respectively, can be tolerated without interference. For 90 s resin loading time, a linear relationship between absorbance and analyte concentration in the 5.00-50.0 μg Cd l-1 range (r2 = 0.9996) is obtained. A throughput of 20 samples per h is achieved, corresponding to about 0.7 mg MG and 500 mg KI and 5 ml sample consumed per determination. The detection limit is 0.23 μg Cd l-1. The accuracy was checked for cadmium determination in standard reference materials, vegetables and tap water. Results were in agreement with certified values of standard reference materials and with those obtained by graphite furnace atomic absorption spectrometry at 95% confidence level. The R.S.D. for plant digests and water containing 13.0 μg Cd l-1 was 3.85% (n = 12). The recoveries of analyte spikes added to the water and vegetable samples ranged from 94 to 104%.en
dc.description.affiliationDepartamento de Química Analítica Instituto de Química Univ. Estadual Paulista (UNESP), PO Box 355, CEP 14801-970 Araraquara, SP
dc.description.affiliationUnespDepartamento de Química Analítica Instituto de Química Univ. Estadual Paulista (UNESP), PO Box 355, CEP 14801-970 Araraquara, SP
dc.format.extent497-503
dc.identifierhttp://dx.doi.org/10.1016/S0039-9140(00)00516-6
dc.identifier.citationTalanta, v. 53, n. 3, p. 497-503, 2000.
dc.identifier.doi10.1016/S0039-9140(00)00516-6
dc.identifier.issn0039-9140
dc.identifier.lattes8708735699846578
dc.identifier.scopus2-s2.0-0034606534
dc.identifier.urihttp://hdl.handle.net/11449/66402
dc.identifier.wosWOS:000165524200003
dc.language.isoeng
dc.relation.ispartofTalanta
dc.relation.ispartofjcr4.244
dc.relation.ispartofsjr1,186
dc.rights.accessRightsAcesso restrito
dc.sourceScopus
dc.subjectCadmium
dc.subjectElectrolytic deposition
dc.subjectFlow analysis
dc.subjectMalachite green
dc.subjectSolid phase extraction
dc.subjectSpectrophotometry
dc.subjectAnodes
dc.subjectCathodes
dc.subjectCopper
dc.subjectElectric currents
dc.subjectElectrochemical corrosion
dc.subjectElectrochemical electrodes
dc.subjectElectrodeposition
dc.subjectElectrolysis
dc.subjectExtraction
dc.subjectIon exchange
dc.subjectLead
dc.subjectMulticommutation flow systems
dc.subjectcadmium
dc.subjectcopper
dc.subjectiodide
dc.subjectlead
dc.subjectmalachite green
dc.subjecttap water
dc.subjectaccuracy
dc.subjectchicory
dc.subjectelectrode
dc.subjectelectrolysis
dc.subjectfood contamination
dc.subjection exchange
dc.subjectnonhuman
dc.subjectreference value
dc.subjectrice
dc.subjectspectrophotometry
dc.subjectspinach
dc.subjectstandard
dc.subjecttomato
dc.subjectvegetable
dc.subjectwater contamination
dc.titleMinimization of lead and copper interferences on spectrophotometric determination of cadmium using electrolytic deposition and ion-exchange in multi-commutation flow systemen
dc.typeArtigo
dcterms.licensehttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
unesp.author.lattes8708735699846578
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Química, Araraquarapt

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