Unlimited-volume electrokinetic stacking injection in sweeping capillary electrophoresis using a cationic surfactant.
Unlimited-volume electrokinetic stacking injection in sweeping capillary electrophoresis using a cationic surfactant.
复制标题
使用阳离子表面活性剂在扫频毛细管电泳中进行无限体积电动堆积注射。
DOI：
10.1021/ac060298x
复制
发表时间：
2006
影响因子：
7.4
通讯作者：
Heineman,WilliamR
中科院分区：
文献类型：
--
作者：
Gong,Maojun;Wehmeyer,KennethR;Limbach,PatrickA;Heineman,WilliamR
扫掠是胶束电动色谱中在线样品预富集的一种简便有效的方法。通常的程序包括通过向样品瓶施加压力进行的流体动力学进样步骤，然后是随后的吹扫和分离过程。进样量受毛细管尺寸的限制，因为毛细管的一部分必须不含样品溶液，以便进行后续的吹扫和分离步骤。此外，当使用短毛细管（如4 - 10 cm）进行吹扫时，即使整个毛细管充满样品溶液，注入的样品体积也很小。为了解决这个问题，电动堆积进样（EKSI）方案的发展，使用阳离子表面活性剂，十二烷基三甲基溴化铵，用于毛细管电泳扫描。提出了实验模型，并对整个过程进行了理论分析。根据理论讨论，实验确定了5-羧基荧光素（5-FAM）和荧光素钠（FL）两种模型分析物的最佳条件。在20.1 kV下持续60 min的5-FAM和FL的注入样品塞长度实验估计为836和729 cm，分别对应于有效毛细管长度的28倍和24倍。与传统的加压进样方法相比，60 min进样的EKSI方法对5-FAM和FL的检测因子分别提高了4.5 × 103和4.0 × 103。
Sweeping is an effective and convenient way for online sample preconcentration in micellar electrokinetic chromatography. The usual procedure includes a hydrodynamic injection step carried out by applying pressure to the sample vial followed by the subsequent sweeping and separation processes. The injected sample volume is limited by the dimensions of the capillary because a part of the capillary has to be left free of sample solution for the subsequent sweeping and separation steps. In addition, when a short capillary, such as 4−10 cm, is used for sweeping, the injected sample volume is small even if the entire capillary is filled with sample solution. To solve this problem, an electrokinetic stacking injection (EKSI) scheme was developed by using a cationic surfactant, dodecyltrimethylammonium bromide, for sweeping in capillary electrophoresis. An experimental model was proposed, and the entire process was theoretically analyzed. According to the theoretical discussion, the optimal conditions for two model analytes, 5-carboxyfluorescein (5-FAM) and sodium fluorescein (FL), were experimentally determined. The injected sample plug lengths for 5-FAM and FL under 20.1 kV for 60 min were experimentally estimated as 836 and 729 cm, corresponding to 28- and 24-fold the effective capillary length, respectively. The EKSI scheme resulted in increased detection factors for 5-FAM and FL of 4.5 × 103and 4.0 × 103using 60-min injection relative to a traditional pressure injection.