Anti-Fouling In Situ Deposited Antimony/Nafion Film Electrode For Electrochemical Stripping Analysis

An antimony film electrode for anodic stripping voltammetric analysis in complex solution was investigated, with lead and cadmium employed as test metal ions. Ascorbic acid or dopamine, which exist in most mammals and their metabolites in relatively high concentrations, interfere with the determination of metal ions by electrochemical stripping analysis. The influence of ascorbic acid and dopamine on the stripping voltammetric response of antimony film electrodes was evaluated. The adsorption of these biomolecules onto the electrode caused decreased and non-distinguishable stripping peaks. The interference of the biomolecules on antimony stripping electrodes can be overcome by Nafion pre-coating. In situ deposited antimony/Nafion-coated glassy carbon electrodes exhibited higher sensitivity for electrochemical stripping analysis of cadmium and lead with limit of detection approximately 0.015 mu g L-1 in the presence of ascorbic acid or dopamine. The effective anti-fouling capability to ascorbic acid or dopamine makes the in situ deposited antimony/Nafion-coated electrode very attractive for direct measurements of trace metals in complex media.