Liu Qingqing, Liu Yaling, Guan Yu, Jia Li
Ministry of Education, Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou, China.
J Sep Sci. 2009 Apr;32(7):1011-7. doi: 10.1002/jssc.200800598.
A new online concentration method, namely pressure-assisted field-enhanced sample injection (PA-FESI), was developed and compared with FESI for the analysis of water-soluble vitamins by CZE with UV detection. In PA-FESI, negative voltage and positive pressure were simultaneously applied to initialize PA-FESI. PA-FESI uses the hydrodynamic flow generated by the positive pressure to counterbalance the reverse EOF in the capillary column during electrokinetic sample injection, which allowed a longer injection time than usual FESI mode without compromising the separation efficiency. Using the PA-FESI method, the LODs of the vitamins were at ng/mL level based on the S/N of 3 and the RSDs of migration time and peak area for each vitamin (1 microg/mL) were less than 5.1%. The developed method was applied to the analysis of water-soluble vitamins in corns.
开发了一种新的在线富集方法，即压力辅助场增强进样（PA-FESI），并将其与场增强进样（FESI）进行比较，用于通过毛细管区带电泳（CZE）结合紫外检测分析水溶性维生素。在PA-FESI中，同时施加负电压和正压力以启动PA-FESI。PA-FESI利用正压力产生的流体动力流在电动进样过程中抵消毛细管柱中的反向电渗流，这使得进样时间比常规FESI模式更长，同时不影响分离效率。使用PA-FESI方法，基于3的信噪比，维生素的检测限为纳克/毫升水平，每种维生素（1微克/毫升）的迁移时间和峰面积的相对标准偏差小于5.1%。所开发的方法应用于玉米中水溶性维生素的分析。
