Simultaneous Determination of Hydroquinone and Catechol at Poly-histidine Film Modified Glassy Carbon Electrode

The poly-histidine (poly-HTD) film was prepared at glassy carbon electrode by electropolymerization, and its electrochemical behavior was investigated by cyclic voltammetry. Results show that the behavior of this poly-HTD film is in good agreement with quasi-reversible process characteristic. At low scan rates, the electronic transfer process of electrode reaction is controlled by surface process. At this poly-HTD film modified electrode, an excellent electrocatalytic ability towards the redox of hydroquinone(HQ) and catechol(CC) with decrease of the overpotential and improvement of the redox peak currents was found. Differential pulse voltammetry was used for the simultaneous determination of HQ and CC in their mixture, and the peak-to-peak separation Delta E-p for HQ and CC was 110 mV. Therefore, this polymer modified electrode can be used for the simultaneously selective determination of HQ and CC without interference with each other.