Indexed on: 01 Jun '03Published on: 01 Jun '03Published in: Chromatographia
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 3.28×106 mol L−1 for tatartic acid, 3.62×106 mol L−1 forcitric acid, 3.84×106 mol L−1 for malic acid, 3.26×106 mol L1 for formic acid, 4.42×106 mol L1 for acetic acid and 3.66×106 mol L1 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.