Determination of grepafloxacin and clinafloxacin by capillar zone electrophoresis

摘要

A simple and rapid capillary zone electrophoresis determination method with UV detection of grepafloxacin and clinafloxacin has been developed. The separation was performed in 35 mM borate-35 mM phosphate buffer solution (pH 8.6), containing 6% (v/v) of acetonitrile. Analyses were realised using fused-silica capillaries (57 cm length * 75 μm I.D.) and the operating conditions were: 15 kV applied voltage, 30 ℃ and detection at 279 nm. Piromidic acid was used as an internal standard. The linear concentration range of application was 1.0-120.0 μg ml~(-1) for both compounds, with a detection limit of 0.2 μg ml~(-1) for grepafloxacin and 0.3 μg ml~(-1) for clinafloxacin. The analysis yielded good reproducibility (RSD between 3.37 and 1.74%). It was applied to the determination of grepafloxacin and clinafloxacin in human and rat urine samples. The method was validated using HPLC as a reference method. Recovery levels were between 94.5 and 103%.