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.
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.
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