【Abstract】 The electrocatalytic oxidation of ascorbic acid(AA) in H2SO4 solution atpolyaniline(PAN) modified electrode was studied by cyclic voltammetry(CV). The electrocatalytic behavior was thected by the PAN filin thickness(D), the pH values of solution,the AA concentration and the metalic cation. The results show that the peak current hasgood linear relationship with the AA concentration at pH=4.5, D=0.1μm in 1o-2 ~10-8mol·L-1 AA. The electroeatalytic activity was strengthened by Cu2+ and Fe2+ ions.The CV behavior was also investigated under the magnetic fields up to 0.7T (1T=104Gauss). Plateaus of limiting currents were observed when the magnetic flux was directedin parallel to the surface of electrode. The phenomena were explained by the enhancementof mass transfer by magnetohydrodynndc (MHD) convection. The magnetic field effectswas found to be pronounced at the slow potential scan rate of 10mV·s-1. But when themagnetic flux directed in perpendicular to the surface of electrode, the effect was not observed.更多还原