Electrochemical oxidation and determination of ascorbic acid present in natural fruit juices using a methionine modified carbon paste electrode

The electrocatalytic behavior of a methionine modified carbon paste electrode and bare carbon paste electrode for the electro-oxidation of ascorbic acid (AA) was studied by using a cyclic voltammetric method. The obtained results showed good enhancement in the anodic peak current in the case of the modified electrode compared to the bare electrode. The anodic peak current showed a linear relationship with increase in the concentration of AA, and a linear calibration curve is obtained in the range of 5.0 × 10−6 to 12 × 10−5 mol L−1 concentration of AA. The applicability of the proposed method was adapted for the determination of the concentration of AA present in real samples and the results were found to be satisfactory.