Quantitative analysis of eight cephalosporin antibiotics in pharmaceutical products and urine by capillary zone electrophoresis

A simple and rapid capillary zone electrophoretic (CZE) method has been established for separation and quantification of a mixture of eight ce-phalosporins – cefadroxil (CFL), cefixime (CIX), cefuroxime sodium (CFR), ceftriaxone sodium (CTR), ceftizoxime (CFT), cefaclor (CFC), cefradine (CFD), and cefotoxime (CTA). Conditions affecting the separation were pH, buffer concentration, and applied potential. Separation was performed in less than 11 min with 50 mM sodium tetraborate buffer, pH 9.0, and an applied potential of 30 kV. Reproducible separation was achieved and calibration plots were linear over two to three orders of magnitude of analyte concentration. Limits of detection were in the range 0.5–5 µg mL–1. De-tection was by UV absorbance at 214 nm. When the method was assessed for analysis of cephalosporins in pharmaceutical preparations and in urine, relative standard deviations (RSD, n = 4) were in the range 0.3–1.9%.