Amperometric detection studies of poly-o-phenylenediamine film for the determination of electroinactive anions in ion-exclusion chromatography

Abstract

An amperometric detector based on the chemical modification of poly-o-phenylenediamine (P-OPD) on a gold electrode was successfully used for the determination of electroinactive anions (SO42−, Cl−, NO3−, F−, CH3COO− and PO43−) by single-column ion-exclusion chromatography. All of the anions were detected conveniently and reproducibly in a linear concentration range of 1.0 × 10−5–5.0 × 10−3 mol L−1. The detection limits of the anions were 2.10 × 10−6 mol L−1 for SO42−, 2.47 × 10−6 mol L−1 for Cl−, 3.53 × 10−6 mol L−1 for NO3−, 3.41 × 10−6 mol L−1 for F−, 5.82 × 10−6 mol L−1 for CH3COO− and 3.86 × 10−6 mol L−1 for PO43− at a signal-to-noise ratio of 3. The proposed method was successfully applied to the analysis of rainwater and river water samples. The electrode was stable during a 2 week period of operation with no evidence of chemical or mechanical deterioration.