Determination of Catechol and Hydroquinone by Using Perilla frutescens Activated Carbon Modified Glassy Carbon Electrode

High specific surface area activated carbon prepared by Perilla frutescens (PFHSAAC) was modified on the surface of the glassy carbon electrode (GCE) by drop-coating method to construct a PFHSAAC/GCE. The electrochemical properties of the modified electrode were investigated in detail by some electrochemical methods such as cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Experiment results show that the modified electrode has excellent redox activity and distinction capability toward the two isomers of catechol (CC) and hydroquinone (HQ). The separation of oxidation peak potential for HQ and CC of DPV is 112.8 mV. Under the optimal conditions, the oxidation peak currents of HQ and CC show good linear relationships with their concentrations in the ranges of 1.0 × 10-6-2.0 × 10-4 and 1.0 × 10-6-1.5 × 10-4 mol L-1, respectively. The limits of detection for HQ and CC are 3.57 × 10-7 and 4.23 × 10-7 mol L-1, respectively. The PFHSAAC/GCE exhibits good stability, repeatability and sensitivity. The developed method was used to determine HQ and CC in water samples with best results.