Determination of Hydroquinone and Catechol at a Poly(arginine acid) Modified Electrode

Abstract

A Poly (arginine acid)/GCE modified electrode was prepared by electrochemical polymerization method, which showed an excellent electrocatalytical activity effect on the redox reaction of catechol and hydroquinone, significantly increased the reversible electrochemical reaction. The electrochemical behavior of catechol and hydroquinone at the modified electrode was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The influences of scan rate and acidity factors on catalytic oxidation of hydroquinone in modified electrode were discussed. The results suggest that the modified electrode was controlled and pH = 7 is the optimum acidity condition for the selective determination and of catechol and hydroquinone. The anodic peak current versus the concentration of hydroquinone showed a linear relation over the range of 6.0´10-6~4.5´10-4 mol/L with a detection limit of 8.0´ 10-7 mol/L, R2=0.997. The anodic peak current versus the concentration of catechol also showed a linear relation over the range of 1.0´10-6~4.8 ´10-4 mol/L, the detection limit was 5.0´10-7 mol/L, R2=0.997. The modified electrode showed good selectivity and strong anti- interference applied to the determination of a water sample with satisfactory results.

Keywords

• Poly (arginine acid)
• Chemically modified electrode
• Hydroquinone
• Catechol.