Electrooxidation of DL-norvaline at Glassy Carbon Electrode: Approaching the Modified Electrode for Voltammetric Studies of Hydroquinone and Catechol

Abstract

ABSTRACT: The DL-norvaline was electrochemically oxidized and deposited on the glassy carbon electrode sur-face using cyclic voltammetry (CV). The modified electrode was examined for electrochemical oxi-dation of hydroquinone (HQ) and catechol (CC). It exhibited good electrocatalytic ability towardstheir oxidation and simultaneous determination in a binary mixture using differential pulse volta-mmetry (DPV). The peak currents were linear to the concentration of HQ and CC, in the range from5 µ M to 100 µ M, and 40 µ M to 140 µ M, respectively. The determination limits(S/N =3) for HQand CC were 1 µ M and 0.8 µ M, respectively. The obtained modified electrode was applied tosimultaneous detection of HQ and CC in water sample.Keywords: DL-norvaline glassy carbon electrode, Hydroquinone, Catechol, Cyclic voltammetry,Differential pulse voltammetry Received September 30, 2013 : Accepted October 30, 2013 1. Introduction The electrooxidation of amino acids has been apotential area for intensive investigation. Their uses asa monomer or a polymer for modification of severalelectrodes have been increasingly used in analyticalapplications. Among several electrode materials,glassy carbon electrodes (GCEs) have been widelyused. The biocompatibility, the low residual currentover a wide range and the minimal chances to showdeteriorated response