Determination of norfloxacin by flow injection electrogenerated chemiluminescence

A new flow injection electrogenerated chemiluminescence (ECL) method for the determination of norfloxacin was developed. The method is based on the sensitizing effect of norfloxacin on the weak ECL signal of electrochemical oxidation of luminol on the platinum flake electrode in the medium of 0.1mol/L Na2CO3-NaHCO3. The experimental conditions that influence the electrogenerated chemiluminescence intensity were investigated and optimized, and the injluence of foreign substances and its elimination were studied. Under the optimum conditions ( luminal concentration: 1 mumol/L, electrolytic potential : 1.4 V (vs. Ag/AgCl), pump speed: 2.0 mL/min). This ECL response is in the range of 1.0 x 10(-5) similar to 0.2 g/L norfloxacin with a detection limit of 4.0 x 10(-6) g/L. The relative standard deviation is 1.2% (n = 11). This method was used to determine norfloxacin in pharmaceuticals and human urine samples with satisfactory results.