Flow-Injection Chemiluminescence Determination of Ofloxacin and Levofloxacin in Pharmaceutical Preparations and Biological Fluids

A novel, rapid and sensitive analytical method is described for determination of ofloxacin and levofloxacin by enhanced chemiluminescence (CL) with flow-injection sampling. The method is based on the CL reaction of the Ce(IV)-Na 2 S 2 O 4 -ofloxacin/levofloxacin-H 2 SO 4 system. The enhanced CL mechanism was developed and the optimum conditions for CL emission were investigated. The CL intensity was correlated linearly (r = 0.9988) with the concentration of ofloxacin (or levofloxacin) in the range of 1.0 × 10 -8 - 1.0 × 10 -7 g ml -1 and 1.0 × 10 -7 - 6.0 × 10 -6 g ml -1 . The detection limit (S/N = 3) is 7 × 10 -9 g ml -1 . The relative standard derivation (RSD, n = 11) is 2.0% for ofloxacin at 4 × 10 -7 g ml -1 and for levofloxacin at 6 × 10 -7 g ml -1 . This method has been successfully applied for the determination of ofloxacin and levofloxacin in pharmaceutical preparations and biological fluids with satisfactory results.