DETERMINATION OF NI(II) IN ALLOYS USING A NEW REAGENT DERIVED FROM L-DOPA

Abstract

A simple and sensitive UV-Vis spectrophotometric method was developed using a new chromogenic reagent, L-dopasemiquinone, for the quantification of Ni(II) in metallic alloys: Inox, Co-Cr, and Ni-Ti. The complex [Ni(II)(L1-)3]1- presents an intense band at 591 nm, ε = 2.4 x 103 L mol-1 cm-1. Beer’s law is obeyed from 4.02 x 10-5 to 2.01 x 10-4 mol L-1 with limits of detection and quantification of 4.15 x 10-5 mol L-1 and 5.02 x 10-5 mol L-1, respectively. The method was compared with atomic absorption spectrophotometry and inductively coupled plasma atomic emission spectroscopy obtaining good results. Cobalt and Titanium cause low interference in the method.