Abstract: A silver doped poly(L-methionine) modified glassy carbon electrode was fabricated through cyclic voltammetric method. The electrochemical behaviors of hydroquinone and catechol on the silver doped poly(L-methionine) modified electrode were investigated. In a phosphate buffer solution with pH=5.0, the modified electrode gave a pair of redox peaks at Epa=0.228 V, Epc=0.162 V for hydroquinone and Epa=0.347 V, Epc=0.287 V for catechol at the scan rates of 100 mV/s. Two peak differences for oxidation or reduction were 119 mV or 125 mV, respectively. Under optimized conditions, the oxidation peak currents were proportional to the concentrations of hydroquinone and catechol, respectively. The linear ranges for the simultaneous determination of hydroquinone and catechol using differential pulse voltammetry were 3.00×10-6～1.00×10-4 mol/L. The detection limits were 8.0×10-7 mol/L for hydroquinone and 5.0×10-7 mol/L for catechol, respectively. The as-established protocol was successfully applied for the simultaneous determination of hydroquinone and catechol in waste water samples with satisfactory results.

Key words: Silver doped poly(L-methionine) modified electrode, Hydroquinone, Catechol, Simultaneous determination, Cyclic voltammetry, Differential pulse voltammetry