Comparison of carbon paste and boron-doped diamond electrodes for determination of cefepime in pharmaceutical dosage forms and biological samples

Abstract

The electrochemical analysis of cefepime, a fourth-generation cephalosporin, was investigated in the direction of oxidation using a carbon paste (CP) electrode and a boron-doped diamond (BDD) electrode. The optimum paste composition was determined as 25 % mineral oil-75 % graphite powder for the CP electrode. The effects of different pHs and scan rates on the anodic peak potential and peak current of cefepime were investigated. Scan rate studies were carried out in the range of 5–200 mV s −1 (vs. Ag/AgCl). It was found that the CP electrode had an adsorption-controlled process and the BDD electrode had a diffusion-controlled process under some adsorption effect. The linear ranges of cefepime obtained for the CP electrode were determined as 0.08–10 μM (correlation coefficient; r = 0.998) for differential pulse stripping voltammetry with a detection limit of 3.73 nM and 0.4–10 μM ( r = 0.998) for square wave stripping voltammetry with a detection limit of 22.1 nM. For the BDD electrode, cefepime gave a linear range of 0.04–10 μM ( r = 0.999) for differential pulse voltammetry with a detection limit of 1.58 nM and 0.4–60 μM ( r = 0.998) for square wave voltammetry with a detection limit 11.0 nM. The precision of the proposed methods was examined by repeatability studies and presented by relative standard deviation (RSD) values below 1.76 %. Quantitative analysis of cefepime from pharmaceutical dosage forms and human serum samples using the developed methods was performed for both electrodes without any separation or filtering pretreatment. Recoveries were between 99.41 and 102.07 % for pharmaceutical dosage forms and between 99.79 and 100.50 % for human serum samples, with RSD ranging from 0.70 % to 0.98 %. • Sensitive detection of cefepime helps to increase the effectiveness of treatment. • Side effects in the treatment can be reduced by the determination of cefepime. • Oxidative determination of cefepime can be done using non-toxic solid electrodes. • Carbon paste and boron doped diamond electrodes offer advantages over each other. • Voltammetric methods enable determination from serum samples without pretreatment.