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dc.contributor.authorTakeuchi, Regina M.
dc.contributor.authorSantos, Andre L.
dc.contributor.authorPadilha, Pedro M.
dc.contributor.authorStradiotto, Nelson Ramos [UNESP]
dc.identifier.citationTalanta. Amsterdam: Elsevier B.V., v. 71, n. 2, p. 771-777, 2007.
dc.description.abstractSolid paraffin-based carbon paste electrodes modified with 2-aminothiazole organofunctionalized silica have been applied to the anodic stripping determination of copper ions in ethanol fuel samples without any sample treatment. The proposed method comprised four steps: (1) copper ions preconcentration at open circuit potential directly in the ethanol fuel sample; (2) exchange of the solution and immediate cathodic reduction of the absorbate at controlled potential; (3) differential pulse anodic stripping voltammetry; (4) electrochemical surface regeneration by applying a positive potential in acid media. Factors affecting the preconcentration, reduction and stripping steps were investigated and the optimum conditions were employed to develop the analytical procedure. Using a preconcentration time of 20 min and reduction time of 120 s at -0.3 V versus Ag/AgCl(sat) a linear range from 7.5 x 10(-8) to 2.5 x 10(-6) mol L(-1) with detection limit of 3.1 x 10(-8) mol L(-1) was obtained. Interference studies have shown a decrease in the interference effect according to the sequence: Ni > Zn > Cd > Pb > Fe. However, the interference effects of these ions have not forbidden the application of the proposed method. Recovery values between 98.8 and 102.3% were obtained for synthetic samples spiked with known amounts of Cu(2+) and interfering metallic ions. The developed electrode was successfully applied to the determination of Cu(2+) in commercial ethanol fuel samples. The results were compared to those obtained by flame atomic absorption spectroscopy by using the F-test and t-test. Neither F-value nor t-value have exceeded the critical values at 95% confidence level, confirming that there are no significant differences between the results obtained by both methods. (c) 2006 Elsevier B.V. All rights reserved.en
dc.publisherElsevier B.V.
dc.sourceWeb of Science
dc.subjectethanol fuelpt
dc.subjectsolid paraffin-based carbon paste electrodespt
dc.subjectorganofunctionalized silicapt
dc.subjectcopper ionspt
dc.subjectdifferential pulse stripping voltammetrypt
dc.titleCopper determination in ethanol fuel by differential pulse anodic stripping voltammetry at a solid paraffin-based carbon paste electrode modified with 2-aminothiazole organofunctionalized silicaen
dcterms.rightsHolderElsevier B.V.
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.description.affiliationUNESP, Inst Quim, Dept Quim Analit, Araraquara, Brazil
dc.description.affiliationUNESP, IB, Dept Quim & Bioquim, Botucatu, SP, Brazil
dc.description.affiliationUnespUNESP, Inst Quim, Dept Quim Analit, Araraquara, Brazil
dc.description.affiliationUnespUNESP, IB, Dept Quim & Bioquim, Botucatu, SP, Brazil
dc.rights.accessRightsAcesso restrito
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Biociências, Botucatupt
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Química, Araraquarapt
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