高效毛细管电泳法拆分氧氟沙星对映体的研究

SEPARATION OF OFLOXACIN ENANTIOMERS BY HIGH PERFORMANCE CAPILLARY ELECTROPHORESIS(HPCE)

用牛血清白蛋白为手性选择剂，异丙醇为修饰剂，应用毛细管电泳法拆分氧氟沙星对映体，实验时柱温为３０℃，电泳电压１５ｋＶ，采用５０ｍｇ·ｍｌ－１牛血清白蛋白—５％异丙醇—磷酸盐缓冲液（ｐＨ６０）为电泳电解液，检测波长为２９３ｎｍ，得到了良好拆分结果。左、右旋成分迁移时间及峰面积的ＲＳＤ分别为１６％，１８％和１１％，２８％。应用于氧氟沙星产品研究，其左、右旋成分峰面积比值为０９９５～０９９８，ＲＳＤ为１８％～２０％。并研究了ｐＨ值、牛血清白蛋白浓度、异丙醇浓度、柱温、电泳电压对对映体迁移时间及分辨率的影响。

An analytical method for separation of ofloxacin enantiomers by HPCE using bovine serum albumin(BSA) as the chiral selector and isopropanol as the modifier was established. The effects of BSA concentration, pH of running buffer, isopropanol concentration, applied voltage and column temperature on the resolution of the enantiomers have been studied. The experimental results indicated that the BSA concentration and pH of the running buffer were the vital factors for the separation of the enantiomers. The concentration of isopropanol showed strong influence on the peak shape of enantiomers. Lower voltage and column temperature were favorable to improve the effieiency for the separation of the enantiomers. Optimum performance was achieved in a fusedsilica capillary(45 cm×30 μm ID, effective length 32 cm) at 30℃ and applied voltage of +15 kV with a pH 60 phosphate buffer containning 50 mg·ml-1 BSA and 5% isopropanol as running buffer and detected at 293 nm. The precison of this method was evaluated by repeated measurement of the migration times and peak areas for 045 mg·ml-1 ofloxacin standard solution. The RSD(n=8) for migration times and peak areas were 16% and 11% for (-)ofloxacin and were 18% and 28% for (+)ofloxacin, respectively. The method was simple and fast and has been applied to separate enantiomers of ofloxacin products. The experimental results showed that the ratio of peak area of (-)ofloxacin to that of (+)ofloxacin was within the range of 0995～0998 with RSD(n=6) of measurement between 18% and 20%.