[Determination of enoxacin in urine by synchronous fluorimetry]

The effect of metal ions on uhe fluorescence spectra of enoxacin was studied in detail. It has been found that aluminum can enhance the fluorescence intensity of enoxacin remarkably in the buffer solution of NaH2 PO4-Na2B4O7 with pH 6.3. A new method using synchronous fluorimetry has been developed for the determination of enoxacin in human urine. The synchronous fluorescence intensity of Al/ENX system is linearly proportional to the concentration of ENX in the concentration range of 0.04-1.0 microg x mL(-1). The detection limit, calculated according to IUPAC recommendations, was 0.018 microg x mL(-1). The precision of the method was established by repeated assays (n = 12) using 0.4 microg x mL(-1) solution of ENX, and the relative standard deviation was 3.1%. The method was satisfactorily applied to the determination of enoxacin in human urine samples. The recovery was within the range of 95%-105%.