Abstract: The electrochemical behavior of polyoxometalate modified electrode is studied by cyclic voltammetry. The results show that :optimal conditions are obtained and the mechanism of catalytic oxidization is inferred. 4×10-8 ～1×10-4mol/Lof the linear range, 1.5×10-8 of the detection limit and 96.9%～102.1% of recovery for ascorbic acid are obtained in the optimal conditions. The proposed method is simplicity, rapidity, sensitivity, and high selectivity, and offer great practical interest for the periodic control of ascorbic acid in fruits and vegetables.

Key words: polyoxometalate, electrochemical behavior, modified electrode