Electrocatalytic Oxidation of Cefixime on the Modified Carbon Paste Electrode with Zeolite Containig Cobalt (CPE/CoZ)

The electrocatalytic oxidation of cefixime on modified carbon paste electrode with zeolite containing cobalt (CPE/CoZ) was investigated. Regarding the significance of determining of Cefixime and its slow oxidation at the surface of bare electrodes, in this work, we aim to use CPE/CoZ to improve electrocatalytic oxidation of cefixime. The process of oxidation and the kinetics have been investigated using cyclic voltammetry, chronoamperometry measurements. Voltammetric studies have indicated that in the presence of cefixime, the anodic peak current of low valence cobalt species increases, followed by a decrease in the corresponding cathodic current. This indicates that cefixime is oxidized on the redox mediator which is immobilized on the electrode surface via an electrocatalytic mechanism. Then, the optimum conditions such as the ratio of zeolite/Co to graphite, pH, etc., were determined to get to the best results. Finally, The rate constant (K=3.18×104cm3 s-1mol-1), and the diffusion coefficient (D=3.12×10-5cm2s-1), in the electrocatalytic oxidation of cefixime were determined. It was shown that by using the modified electrode, cefixime can be determined by chronoamperometric technique in linear range 8×10-3M to 3×10-6M and with detection limit of 2.98 ×10-6 M, respectively.

کلیدواژه ها:

Cefixime ، Voltammetry ، Chronoamperometry ، modified electrode ، zeolite containing cobalt (CPE/CoZ)