Simultaneous detection of hydroquinone and catechol on electrochemical-activated glassy carbon electrode by simple anodic and cathodic polarization

Herein, we report a simple method of simultaneous detection of hydroquinone (HQ) and catechol (CC) by cyclic voltammetry (CV) using activated glassy carbon electrodes (GCE). It was found that the two isomers can be completely separated by CV method on cathode polarized GCE (PGCE) after its anodic oxidation. This facile processing method solves the difficulty of electrode surface regenerating which disturb most modified electrodes for the complex composition ease of being contaminated by the analytes in measurement. Morphology and composition of the PGCE were characterized by scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectra, and X-ray photoelectron spectroscopy. In addition, the reaction kinetic of HQ and CC reaction on the PGCE was investigated. It was found that the reaction kinetics of HQ and CC is a surface adsorption-controlled process at low concentration and a diffusion-controlled process at high concentration.