Determination of 2,4-dimethylphenol by anodic voltammetry and flow injection with amperometric detection at a glassy carbon electrode

Abstract

An electroanalytical study of the oxidation of 2,4-dimethylphenol (2,4-DMP) at a glassy carbon electrode in aqueous solutions using different voltammetric techniques has been carried out. The results obtained with differential-pulse voltammetry, using a pulse amplitude of 50 mV, in 0.1 mol l^–1 perchloric acid and in a 0.1 mol l^–1 Britton–Robinson buffer solution of pH 10.0 allowed the development of two methods for the determination of 2,4-DMP in the ranges from 2.0 × 10^–6 to 3.5 × 10^–5 and 2.0 × 10^–6 to 4.0 × 10^–5 mol l^–1, with limits of detection of 7.2 × 10^–7 and 7.5 × 10^–7 mol l^–1, respectively. Flow-injection methods with amperometric detection based on such an oxidation process are also described; calibration graphs were linear within the ranges 0.01–4.0 mg l^–1 in 0.1 mol l^–1 perchloric acid at a potential of +1.00 V and 0.01–5.0 mg l^–1 in a 0.01 mol l^–1 Britton-Robinson buffer solution of pH 10.0 at a potential of +0.75 V, with limits of detection of 4 and 7 µg l^–1(3.3 × 10^–8 and 5.8 × 10^–8 mol l^–1) of 2,4-DMP, respectively. The proposed methods were applied to the determination of 2,4-DMP in water samples and good results were obtained.