Simultaneous determination of tetracaine, proline, and enoxacin in human urine by CE with ECL detection

A simple, fast, and sensitive capillary electrophoresis method was developed for the simultaneous determination of tetracaine, proline, and enoxacin in human urine with electrochemiluminescence (ECL) detection. The effects of experimental conditions including the mode of applied voltage signal, the potential of working electrode, pH value, the flow rate of carrier of solution, the concentration of Ru(bpy)(3)(2+), and the ECL intensity of the drugs were investigated in detail. Parameters related to the separation and detection were investigated and optimized. Under optimized conditions, the proposed method displayed a linear range from 0.4 to 100 microg/mL for tetracaine, 0.2 to 80 microg/mL for proline, and 0.1 to 100 microg/mL for enoxacin. Their limits of detection were 0.08, 0.06, and 0.02 microg/mL, respectively. A baseline separation for tetracaine, proline, and enoxacin was achieved within 10 min. Developed method was successfully applied to determine tetracaine, proline, and enoxacin in human urine.