Determination of Cr(VI) in the presence of high excess of a Cr(III) by adsorptive stripping voltammetry

► A stripping voltammetric procedure for Cr(VI) determination in the presence of large excess of Cr(III) was proposed. ► For minimization of Cr(III) interference, adsorption of this form of chromium from the sample on Al2O3 was exploited. ► The first time separation of chromium forms on Al2O3 was coupled with species selective voltammetric detection method. ► Al2O3 adsorbs organic substances present in natural samples and minimizes their interference in stripping voltammetric method.