Differential Pulse Voltammetric Determination of Quercetin with Ferrocene Modified Carbon Paste Electrode

Ferrocene modified carbon paste electrode was prepared, and the electrochemical behavior of quercetin of this modified electrode was studied by cyclic voltammetry. It was found that significant electro-catalytic action of the modified electrode was observed on the reaction of quercetin at the electrode, giving a pair of oxidation and reduction peak in PBS of pH 6.2. The oxidation of quercetin at the modified electrode is controlled mainly by adsorption in an electrode process involved with 2 electrons and 2 protons. Based on this fact, a method of differential pulse voltammetry was proposed for the determination of quercetin. Linear relationship between values of oxidation peak current and concentration of quercetin was obtained in the range from 8×10-4 to 2×10-6mol·L-1, with detection limit (3S/N) of 7×10-6mol·L-1.