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A new Cu(II)-5-(4-sulphophenylazo)-8-aminoquinoline complex used for copper determination in presence of gold and silver in water and mineral samples.
Morales, Libby; Toral, M Inés; Alvarez, M José.
Afiliação
  • Morales L; Department of Chemistry, Faculty of Sciences, University of Chile, PO Box 653, Santiago, Chile.
Talanta ; 74(1): 110-8, 2007 Nov 15.
Article em En | MEDLINE | ID: mdl-18371619
In this work, a characterization of reagent chromophore 5-(4-sulphophenylazo)-8-aminoquinoline [SPA] by IR and 1H RMN was carried out and a pK(a) value of 3.55+/-0.03 was found as well. An 1:2 stoichiometry for the Cu(II)-SPA complex was determined at pH 9 by Job and molar ratio methods. A value of 1.4 x 10(14) for the stability constant was also found. Based on the formation of this complex a new method for the copper determination in presence of gold and silver was developed by derivative spectrophotometry using a previous preconcentration on solid phase. In this method, the analytical measures were executed directly in the solid phase containing the complex. The Cu(II) reacts with the reagent chromophore SPA previously retained in the anionic exchange DEAE Sephadex A25. In this determination, the first derivative at 605 nm was used. The quantification range was between (3.2+/-0.3 x 10(-1)) x 10(-8) and (94.4+/-0.9) x 10(-8) mol L(-1) (3.2+/-0.3 x 10(-1)) x 10(-8), and (94.4+/-0.9) x 10(-8) mol L(-1). The repeatability expressed as RSD was between 1.1 and 2.0%. The method was applied successfully for the copper determination in mineral residuals and natural water samples. The results were consistent with those provided by ICP-mass spectrometry.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Prata / Poluentes Químicos da Água / Cobre / Ouro / Aminoquinolinas Idioma: En Revista: Talanta Ano de publicação: 2007 Tipo de documento: Article País de afiliação: Chile País de publicação: Holanda

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Prata / Poluentes Químicos da Água / Cobre / Ouro / Aminoquinolinas Idioma: En Revista: Talanta Ano de publicação: 2007 Tipo de documento: Article País de afiliação: Chile País de publicação: Holanda