Highly Sensitive Chemiluminescence Detection of Norfloxacin and Ciprofloxacin in CE and Its Applications

A highly sensitive and rapid method for the determination of norfloxacin and ciprofloxacin was developed using capillary electrophoresis coupled with chemiluminescence detection. The chemiluminescence detection was based on the enhancing effects of two analytes on the luminol-hydrogen peroxide reaction. The baseline separation of norfloxacin and ciprofloxacin was obtained within 4.5 min under the optimum conditions. The limits of detection (S/N = 3) of norfloxacin and ciprofloxacin were 2.9 × 10⁻¹⁰ and 1.1 × 10⁻¹² mol L⁻¹, respectively. The method showed wide linear range with four orders of magnitude (R ≥ 0.9982). The limits of quantification (S/N = 10) of two analytes in human urine samples were 6.0 × 10⁻⁸ and 5.1 × 10⁻¹⁰ mol L⁻¹, respectively. The proposed method was successfully applied to the analysis of norfloxacin and ciprofloxacin in human urine samples and the monitoring of pharmacokinetics of ciprofloxacin in human body.