The Spectrophotometric Determination of Enoxacin Based on the Charge Transfer Reaction Between Enoxacin and Alizarin Red

A spectrophotometric method for the determination of enoxacin was proposed based on the charge transfer reaction between enoxacin (as electron donor) and alizarin red (as electron acceptor) in ethanol-water medium. Apparent molar absorptivity of the complex was 8.04×103 L·mol-1·cm-1 at 546 nm,with its composition ratio of 1 to 1 and stability constant of 2.84×104. Beer′s law was obeyed in the range within 40 mg·L-1 of enoxacin (r=0.999 9). The values of average recovery found were over 99.0%. Value of RSD′s (n=6) obtained was 1.2% at the concentration level of enoxacin 20 mg·L-1. The present method has been applied to the determination of enoxacin in preparations and the results were found to be in consistency with those determined by method given in literature<参考文献原文>.