Empleo de métodos catalíticos para la cuantificación de metales pesados: Reducción de resazurina para la determinación de Cu(II) y Ni(II)

DIANA M. MAGNI; SEBASTIÁN E. COLLINS; ALEJANDRO C. OLIVIERI; ADRIAN L. BONIVARDI

Gramado, Brasil

Simposio; XX Simpósio Ibero-americano de Catálise; 2006

Federación Iberoamericana de Catálisis (FisoCat)

A spectrophotometric catalytic method was used in the determination of Cu(II) and Ni(II) in aqueous solution employing a stopped-flow injection system. The method is based on the catalytic effect of those ions upon the reduction of resazurin by sulfide. Two kinetics mechanisms were applied to study the resazurin reduction in a concentration range of 0.5-3 and 2.5-9 mg l-1 for Cu(II) and Ni(II), respectively. It was proved statistically that the autocatalytic model describes our experimental results, and that this model allowed us to obtain a good analytical relationship between a kinetic constant and the concentration of the catalysts. The parametric method of autocatalytic modeling was applied for the determination of Cu(II) and Ni(II) in real samples and the results agreed with those obtained by the use of flame atomic absorption spectrometry and a non-parametric approach method (artificial neural networks