Separation of tri- and hexavalent chromium prior to voltammetric determination

Abstract

A pre-treatment procedure for determination of traces of Cr(VI) in samples with large excess of Cr(III) by catalytic adsorptive tripping voltammetry is described. Selective determination of Cr(VI) was possible due to quantitative sorption of Cr(III) on chelating resin-Chelex 100. The chelating medium was added directly to the voltammetric cell containing a sample with fixed pH (pH=6.2). After the sorption step, the CAdSV procedure was applied. This procedure was compared to other methods of elimination of the voltammetric signal from Cr(III) excess.