Differential Pulse Voltammetric Determination of Ascorbic Acid with PVP-MWCNT′s/GCE

Through the action of ultrasonic radiation, the composite material of polyvinylpyrrolidone (PVP) and multiwall carbon nanotubes (MWCNT′s) was prepared and dispersed in N,N-dimethylformamide (DMF). The dispersion was then dropped onto the surface of glassy carbon electrode (GCE) to give the modified electrode, designated abbreviately as PVP-MWCNT′s/GCE. It was found that ascorbic acid showed a pair of reversible oxidation and reduction peaks at PVP-MWCNT′s/GCE. Based on this finding, a selective method for the determination of ascorbic acid by differential pulse voltammetry was proposed. Linear relationship between values of reduction peak current and concentration of ascorbic acid was obtained in the range of 1.0×10-7-1.0×10-3mol·L-1.