场放大进样反向迁移胶束电动色谱法富集分离检测尿样中麻黄碱类兴奋剂

On-line Concentration by Field-enhanced Sample Injection with Reverse Migrating Micelles in Micellar Electrokinetic Capillary Chromatography for the Analysis of Ephedrine Dope in Urine

以麻黄碱类兴奋剂(麻黄碱和伪麻黄碱)为研究对象,开展了毛细管电泳反向胶束迁移在线富集分离方法的研究,通过对分离和富集条件的优化,研究建立了毛细管电泳反向迁移胶束在线富集技术测定麻黄碱和伪麻黄碱的方法。确定了缓冲液组成为50 mmol/L磷酸-160 mmo L/L SDS-20%(V/V)乙腈-15%(V/V)异丙醇(p H 2.0)的最佳分离条件;-8 k V电压下压力进样,进样时间为15 s,进样前注入水柱2 s,样品溶液基质为5 mmol/L SDS的最佳富集条件。优化条件下,麻黄碱和伪麻黄碱基线分离,两种麻黄碱富集率分别为60和66倍,并用该方法对尿液中两种麻黄碱进行了测定。结果表明,该方法可以满足运动员尿液中麻黄碱类兴奋剂的检测。

A CE method was developed for the enrichment and determination of ephedrine（ EP）,pseudoephedrine（ PEP） in urine.Field-enhanced sample injection with reverse migrating micelles（ FESI-RMM） was used for on-line concentration of the EP and PEP. The optimum buffer contained 50 mmol / L H3PO4,160 mmol/L SDS,20% acetonitrile and 15% 2-propanol and the p H of buffer was 2. 0. The sample solution was diluted with water containing 5 mmol / L SDS and injected for 15 s with- 8 k V after injection of 2 s water plug. The effects of concentrations of sodium dodecyl sulfate（ SDS） and organic modifier,the sample matrix,the injection time of water plug,the injection voltage and injection time of sample on the separation and stacking efficiency were investigated. Under the optimum conditions,the analytes were well separated and by optimizing the stacking conditions,about 60 and 66 fold improvement in the detection sensitivity was obtained for EP and PEP. The EP and PEP in spiked urine were successfully determined with satisfactory repeatability and recovery.