Determination of chromium(vi) by anodic stripping voltammetry using a silver-plated glassy carbon electrode

Abstract

In this work, differential pulse anodic stripping voltammetry (DP-ASV) for the determination of trace amounts of hexavalent chromium (Cr(VI)) at a silver plated glassy carbon electrode (Ag plated-GCE) is described in detail. A Ag film was prepared by in situ plating of silver on the glassy carbon electrode surface. Several solution conditions and instrumental parameters influencing the electroanalytical response of the Ag plated-GCE were examined and optimized for the determination of Cr(VI). Under the optimized conditions, the calibration curve obtained in CH₃COOH/NH₃ (aq) medium at pH 5.9 was linear over the wide concentration range of 0.35–40 μM Cr(VI). The present method shows a low limit of detection of 0.10 μM. After evaluation of effects from possible interferences, the proposed method was successfully applied for the quantification of Cr(VI) in real water samples, with satisfactory recovery (97–105%). This method is useful for the determination of chromium in drinking water and achieves sensitivity capable of detecting the limits set by the World Health Organization (WHO).