Flow-Injection Determination of Cephalosporin Antibiotic Cefixime in Pharmaceutical Formulations with Luminol-Diperiodatoargentate(III) Chemiluminescence Detection

A simple and sensitive flow injection chemiluminescence method was developed for the determination of cefixime trihydrate (CFX) based on its enhancing effect on chemiluminescence (CL) of luminol-diperiodatoargentate(III) (Ag(III) complex) in an alkaline solution. A linear CL response for CFX from 0.005 to 3 mg/L (y = 566.3x + 12.1, R-2 = 0.9998, n = 10) was achieved with limits of detection and quantification of 0.001 (S/N = 3) and 0.003 mg/L (S/N = 10), respectively, relative standard deviations (RSDs) from 1.0 to 3.4%, and injection throughputs of 90/h. The pharmaceutical samples containing CFX were extracted by liquid-liquid extraction utilizing diethyl ether, analyzed, and satisfactory results were achieved with recoveries of 98 to 105% and RSDs of 1.6 to 3.6% (n = 4). The samples were also analyzed with the reported spectrophotometric method, and results assessed by applying statistical tests were not different significantly. The interference effects of excipients commonly found in formulations, anions, and cations were also evaluated. Chemiluminescence mechanism was proposed by application of UV-Vis spectrophotometry.

Automated summary

A simple and sensitive flow injection chemiluminescence method was developed for the determination of cefixime trihydrate. The chemiluminescence of luminol-diperiodatoargentate(III) in an alkaline solution was enhanced by cefixime trihydrate, allowing for a linear detection range and low limits of detection and quantification. The method was successfully applied to the analysis of pharmaceutical samples containing cefixime trihydrate.