Voltammetric determination of cefotaxime using potassium peroxomonosulfate

Abstract

The presented article is dedicated to the development of new procedure for quantitative voltammetric determination of cefotaxime powder for injection solution preparation in the form of corresponding S-oxide in weak acidic medium using potassium hydrogenperoxomonosulfate (KHSO5) as an analytical reagent. Voltammogramms of cefotaxime S-oxide solutions for different concentrations of cephalosporins were scanned. There are two peaks on the voltammetric curve of the cefotaxime S-oxide solution: at -0.65 V (that corresponds to potassium peroxomonosulfate) and -1.3 V (peak height was rising proportionally to cefotaxime concentrations increasing) that has been chosen as analytical. The calibration curve method can be easily applied. Linearity has been studied over a drug concentration range from 1·10-4 to 1·10-3 mol L-1. The correlation coefficient r=0.999. Precision and accuracy have been studied by analyzing five replicates of the sample solutions at three concentrations levels. The calculated relative standard deviations were below 1.75 %, d ≤ -1.1 % indicating excellent precision of the proposed procedure. The Limit of Detection (LOD) and the Limit of Quantification (LOQ) were calculated (LOD=1.2·10-5 mol L-1 and LOQ= 4·10-5 mol L-1). The proposed voltammetric method is sensitive enough, accurate, precise, replicable and linear to enable determination of lower amounts of drug. These advantages encourage the application of the method in routine quality control of cefotaxime in industrial laboratories.