Effective Separation and Simultaneous Detection of Gatifloxacin, Aminomethylbenzoic Acid, Cefazolin and Cefminox in Human Urine by Capillary Zone Electrophoresis

Gatifloxacin (GAFX), P-aminomethylbezoic acid (PAMBA), cefazolin (CFZL) and cefminox (CMNX) can be combined and administered perorally or intravenously, and are excreted mainly into the urine. A novel capillary zone electrophoresis (CZE) method was developed, for the first time, for an effective separation and simultaneous determination of the said four drugs in human urine. The electrophoresis conditions were investigated and optimized. A 25 mM borate buffer (pH 9.2) was used and the peak area was determined with UV detection. Under optimal conditions, the four drugs can be separated effectively. Good linearity was achieved with the correlation coefficients (r(2)) of > 0.999. The limit of detection (LOD) for PAMBA, GAFX, CFZL and CMNX was 5.8, 3.9, 7.8 and 15.0 mu g ml(-1), respectively. Their average recovery in human urine was 93.2, 98.3, 108 and 92.7%, respectively, with the RSDs ranging from 1.0% to 3.5%. The proposed method is simple, rapid and accurate, and provides the sensitivity and linearity necessary for the selective and simultaneous analysis of the test drugs in human urine at clinically relevant concentrations.