CE-ECL detection of gatifloxacin in biological fluid after clean-up using SPE

A simple, rapid and sensitive CE method has been proposed for the determination of gatifloxacin in biological fluid. This method is based on the ECL reaction of gatifloxacin and tris(2,2'-bipyridyl)ruthenium(II) occurred in the end-column detection cell. Under the optimal conditions, gatifloxacin can be assayed within 10 min over the concentration range of 5.0×10−8−5.0×10−6 g/mL with the theoretical plate numbers of 18 000. The intra-day and inter-day precision of the signal intensity and the migration time shows acceptable reproducibility for the analysis of gatifloxacin. The presented method has been successfully applied to determine the concentrations of gatifloxacin in urine and blood samples after clean-up using C18 SPE column.