Simultaneous Determination of Ascorbic Acid, Dopamine, and Uric Acid by Differential Pulse Voltammetry using Tiron Modified Glassy Carbon Electrode

A highly selective voltammetric method was developed for the simultaneous determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA) using Tiron polymer film modified on glassy carbon electrode. The modified electrode separated the anodic oxidation peaks potential of AA, DA and UA with a well-defined peak separation in the present of each other to measure AA, DA and UA individually or simultaneously without any intermolecular effect. The calibration curves were obtained over the range of 4.0-792.0 µmol/L AA, 0.2-45.8 µmol/L DA, and 0.06-166.0 µmol/L UA. Detection limits of 1.79 µmol/L AA, 0.07 µmol/L DA, and 0.021 µmol/L UA were obtained at pH 3.0. The interference of potential interfering substances on the determination of AA, DA and UA were studied, and the results confirm the selectivity of the method. The modified electrode was used for the determination of AA, DA, and UA simultaneously in real samples such as drugs, urine, and synthesis samples, with satisfactory results