Voltammetric resolution of catechol and hydroquinone at eosin Y film modified carbon paste electrode

Abstract

A sensitive, selective and reproducible electrochemical method was developed for the electroanalysis of catechol (CC) and hydroquinone (HQ) using eosin Y film modified carbon paste electrode (eosin Y/CPE). The modified electrode lowers the over potential and favours the oxidation of CC and HQ. The effect of scan rate and concentration studies reveals that the electrode process is controlled by the adsorption of an analytes. The simultaneous separation of CC and HQ was achieved in a binary mixture by cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. The separation of the oxidation peak potentials for CC–HQ was about 0.114V and 0.118V by CV and DPV techniques respectively. This peak differences were large enough to determine CC and HQ individually or simultaneously. The lower limit of detection of CC was 0.27μM and 0.79μM for HQ. The eosin Y/CPE was achieved the voltammetric separation of the dihydroxy benzene isomers in a binary mixture by CV technique; this work provides a simple and easy approach for the modification of the bare carbon paste electrode.