非水毛细管电泳测定左炔诺孕酮方法的研究

Non-aqueous capillary electrophoresis method for the analysis of levonorgestrel

目的:建立非水毛细管电泳技术测定左炔诺孕酮含量的新方法。方法:以57cm×75μm未涂层空心毛细管柱为分离通道,采用甲醇-乙腈(95:5)为溶剂,25mmol·L(-1)醋酸钠溶液(pH 8.9)为电泳介质,于240nm 波长柱上检测,分离电压25kV,电压进样(10kV×5s),采用峰面积内标法定量。结果:在选定的电泳条件下,左炔诺孕酮的浓度在101.2～506.0μg·mL(-1)范围内与峰面积比呈良好的线性关系(r=0.9993);低、中、高3种浓度的平均回收率(n=3)分别为100.0%,99.12%,99.80%;方法的检测限(S/N=3)为10.12μg·mL(-1);日内和日间峰迁移时间的 RSD 分别为1.8%和2.8%,峰面积的 RSD 分别为1.6%和2.0%。结论:该方法试剂用量少、简便、准确,可用于左炔诺孕酮质量的分析。

Objective： To establish a new non -aqueous capillary electrophoresis method for determination of levonorgestrel. Methods： Fused - silica capillary 57 cm × 75 μm was used. Levonorgestrel could be determined in 25 mmol . L^-1 sodium acetate（pH 8.9） in methanol- acetonitfile（95： 5） as the solvent. The effects of concentration and pH of the running buffer, running voltage was studied. The separation voltage was 25 kV, the injection voltage and injection time were 10 kV and 5 s. The UV detector was set at 240 nm. Internal calibration curve of peak area was selected. Results： There was excellent linearity between the peak area ratio and concentration of the levonorgestrel in the concentration range of 101.2 -506.0 μg . mL^-1. The correlation coefficient was 0. 9993, the detection limit of levonorgestrel at three times the signal -to -noise was 10. 12 μg · mL^-1 The average recovery（ n = 3） were 100. 0% ,99. 12% and 99.80% respectively at the lower, middle and higher concentration. The relative standard deviation values for migration time of intra - assay and inter - assay were 1.8% and 2. 8% respectively. The relative standard deviation values for peak area were 1.6% and 2.0% respectively. Conclusions：This is beneficial for routine quality control analysis of levonorgestrel tablets, the results demonstrate the method is less in solvent consumption, simple, rapid and accurate.