Electrochemical determination of vitamin C in the presence of uric acid by a novel TiO2 nanoparticles modified carbon paste electrode

The electrochemical behavior of vitamin C (ascorbic acid or AA) is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2,2′-(1,2 butanediylbis(nitriloethylidyne))-bis-hydroquinone (BBNBH). The prepared modified electrode showed an efficient catalytic role in the electrochemical oxidation of AA, leading to remarkable decrease in oxidation overpotential and enhancement of the kinetics of the electrode reaction. This modified electrode exhibits well-separated oxidation peaks for AA and uric acid (UA). The modified electrode is successfully applied for the accurate determination of AA in pharmaceutical preparations.