Analytical Sciences

Self-doped Anthranilic Acid-Pyrrole Copolymer/Gold Electrodes for Selective Preconcentration and Determination of Cu(I) by Differential Pulse Anodic Stripping Voltammetry

M. R. NATEGHI and M. H. FALLAHIAN

Department of Chemistry, Azad University, Yazd Branch, Yazd, Iran

Electropolymerization of anthranilic acid/pyrrole (AA/PY) at solid substrate electrodes (platinum, gold, and glassy carbon) gave stable and water-insoluble films under a wide range of pH. Combining high conductivity of the polypyrrole (PPY) and pH independence of the electrochemical activity of the self-doped carboxylic acid-substituted polyaniline allows us to prepare an improved functionalized PPY-modified electrode to collect and measure Cu(I) species. The differential pulse stripping analysis of the copper ions using a polyanthranilic acid-co-polypyrrole (PAA/PPY)-modified electrode consisted of three steps: accumulation, electrochemical reduction to the elemental copper and stripping step. Factors affecting these steps, including electropolymerization conditions, accumulation and stripping medium, reduction potential, reduction time and accumulation time, were systematically investigated. A detection limit of 5.3 × 10^-9 M Cu(I) was achieved for a 7.0 min accumulation. For 12 determinations of Cu(I) at concentrations of 1.0 × 10^-8 M, an RSD of 3.5% was obtained. The log I_p was found to vary linearly with log[Cu^I] in the concentration range from 7.0 × 10^-9 to 1.0 × 10^-5 M.

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