Hamed Bagheri - Department of Chemistry, Faculty of Science, Kerman branch, Islamic Azad University, Kerman, Iran
Mahdiyeh Ghazizadeh - Department of Chemistry, Faculty of Science, Kerman branch, Islamic Azad University, Kerman, Iran
Hamideh Asadllahzadeh - Department of Chemistry, Faculty of Science, Kerman branch, Islamic Azad University, Kerman, Iran

This research describes the development and electrochemical utilization of iron oxide nanoparticles on a multi walled modified carbon paste electrode. The electrochemical behaviorof ascorbic acid on this modified electrode was studied using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The electrochemical profile of the prepared modified electrode by cyclic voltammetry showed a considerable shift of the oxidation peakpotential of ascorbic acid to less positive value and the anodic peak current was enhanced several times in comparison to the unmodified carbon paste electrode. The effect of some experimental parameters such as pH, scan rate, concentration of ascorbic acid and supporting electrolyte wereinvestigated. The results exhibited that the oxidation of ascorbic acid was irreversible and demonstrated diffusion controlled process depending on pH. At the optimum conditions, the concentration of ascorbic acid in 0.1 M phosphate buffer solution at pH 6.0 was performed byusing cyclic voltammetry in a linear range of 0.05 to 7.5 mM with a correlation coefficient of 0.997 and detection limit of 0.001 mM and using differential pulse voltammetry in a linear rangeof 0.05 to 7.5 mM with a correlati0n coefficient of 0.999. These results show that the modified carbon paste electrode has high sensitivity, reproducibility and repeatability. This electrode also used for determination of ascorbic acid in real samples.

Ascorbic acid, cyclic voltammetry, differential pulse voltammetry, iron oxide nanoparticles, Carbon paste electrode