Determination of electroinactive organic acids in red wine by ion-exclusion chromatography using a poly-o-phenylenediamine film modified electrode

In this article, an ion-exclusion chromatography method combined with amperometric detection at a poly-o-phenylenediamine (POPD) film modified gold electrode provided a convenient analytical method for the determination of some electroinactive organic acids. The electrochemical behaviors of some aliphatic acids at POPD chemically modified electrode (CME) have been investigated by Differential Pulse Voltammetry (DPV). Under the optimum ion chromatographic conditions, tartaric acid, citric acid, malic acid, formic acid, acetic acid and succinic acid could be separated in 15 min. The detection limits of these organic acids were 3.28 × 10^-6 mol L^-1 for tatartic acid, 3.62 × 10^-6 mol L^-1 for citric acid, 3.84 × 10^-6 mol L^-1 for malic acid, 3.26 × 10^-6 mol L^-1 for formic acid, 4.42 × 10^-6 mol L^-1 for acetic acid and 3.66 × 10^-6 mol L^-1 for succinic acid (S/N = 3), respectively. The proposed method had been applied to the measurement the organic acids in red wine with satisfactory results. The electrode was very stable and there was no evidence of chemical and mechanical deterioration about 10 days.