Electrochemical oxidation of antibacterial drug cefepime and its quantitative determination from pharmaceuticals and serum with carbon based electrodes

Electrochemical analysis of cefepime which is a cephalosporin antibiotic was studied in the direction of oxidation using boron-doped diamond electrode and carbon paste electrode. Scans were performed using buffer solutions at different pHs with cyclic voltammetry for both electrodes. Cefepime was determined to oxidize as diffusion controlled with scan rate study on boron-doped diamond electrode. Quantitative analysis of cefepime was done using differential pulse voltammetry and square wave voltammetry methods. Linear ranges of cefepime obtained from the calibration graphs using boron-doped diamond electrode were determined as 0.04 - 10 µM (correlation coefficient 0.999) for differential pulse voltammetry and 0.4 - 60 µM (correlation coefficient 0.998) for square wave voltammetry with the detection limits of 1.58x10-3 and 1.10x10-2 µM, respectively. Optimum paste composition for carbon paste electrode was determined as 25%. The oxidation process was adsorption controlled by scan rate study. According to the calibration graphs, linear ranges for differential pulse voltammetry were obtained as 0.08 - 10 µM (correlation coefficient 0.999) for differential pulse stripping voltammetry and 0.4 - 10 µM (correlation coefficient 0.998) for square wave stripping voltammetry with the detection limits of 3.73×10-3 and 2.21×10-2 µM, respectively. Precision of the methods was examined with repeatability studies. Quantitative analysis of cefepime from pharmaceutical dosage forms and human blood serum was done for both electrodes without any separation with these developed methods.