Simultaneous determination of trace ofloxacin and enoxacin by TLC-fluorescence spectrodensitometry

Ofloxacin( OFLX) and enoxacin(ENX)are the broad-spectrum F-quinolone antibiotics and used in clinical treatment. They have a very strong tendency to form coordinate compounds with transition metal ion(1). In recent years,some authers have studied the analysis methods for the determination of the two compounds in body fluid such as microorganism method(2), spectrophotometric analysis(3 4), HPLC5 6, electrochemical analysis(7 8), However, these methods suffered from long analytical time and were not sensitive. A TLC-F method is a new analytical technique combing trace analysis with separation technique and is widely used in pharmaceutical analysis. A TLC-F method for the simultaneous determination of trace OFLXand ENX in body fluid has not been reported previously. Many experiments have shown that the chromatogram of OFLX and ENX on a silica gel plate modified without EDTA is bandform and serious for tailing. Because the two compounds can easily form complexes with transition metals,it becomes difficult for the two compounds to separate. The pretreatment of plates with EDTA may prevent the formation of the complexes. Regular and clear fluorescent Spots of the two compounds are obtained and tailing is avoided under these conditions. The effects of the concentration and pH of the EDTA solution used to treat the silica gel plate were examined. It is shown that the best separation is obtained using a silica gel plate treated with 0.27 mol liter(-1) EDTA solution adjusted to pH 7.0.