Determination of Pazufloxacin Mesylas by Capillary Electrophoresis with Electrochemiluminescence Detection

A novel, sensitive, and rapid method was developed for the determination of pazufloxacin mesylas (PM) by capillary electrophoresis with electrochemiluminescence detection (CE-ECL). It was based on the phenomenon that in base medium, PM enhanced the ECL intensity of tris (2,2′-bipyridyl) ruthenium (II). The influence of several experiment factors such as the detection potential, the concentration of tris (2,2′-bipyridyl) ruthenium (II), the concentration and the pH of phosphate buffer, the electro-kinetic voltage, the injection time, and the separation voltage on the determination of PM was explored in detail. Under the optimized conditions, the detection of PM could be accomplished within three minutes. The enhanced ECL intensity was linear with PM concentration in the range of 0.02−10 mg l−1 (r = 0.9968) with detection limit (S/N = 3) of 4.0 μg l−1. The relative standard deviations (RSD) of ECL intensity and the migration time for eleven continuous injections of 2.0 mg l−1 PM were 4.28% and 1.89%, respectively. This method was successfully applied to PM assay in real samples including injection and human urine. An elementary mechanism was proposed to explain this phenomenon.