Nishi H, Terabe S
Analytical Chemistry Research Laboratory, Tanabe Seiyaku Co. Ltd., Osaka, Japan.
J Pharm Biomed Anal. 1993 Nov-Dec;11(11-12):1277-87. doi: 10.1016/0731-7085(93)80114-g.
Electrokinetic chromatography (EKC) is one branch of capillary electrophoresis that permits the separation of electrically neutral solutes by the electrophoretic technique. The separation principle of EKC is based on that of chromatography, and various modes of EKC have been developed along with the partition mechanism. Micellar electrokinetic chromatography (MEKC), in which an ionic surfactant solution is employed instead of a buffer solution in capillary zone electrophoresis (CZE) at a higher concentration than the critical micelle concentration (CMC), has become the most popular technique among various EKC modes. Besides the separation of the electrically neutral or non-ionic solutes, MEKC is also effective for the separation of ionic solutes as well as CZE, hence it suits the analysis of pharmaceuticals, including cationic, anionic and neutral. Separation selectivity in MEKC can be manipulated easily through the modification of the buffer as well as changing the surfactants. Direct enantiomeric separation is successful by using chiral surfactants or chiral additives. Determination of drugs in plasma is also successfully achieved by a direct sample injection method, similar to micellar HPLC. In this paper, we summarize the principle separation characteristics of MEKC and some applications to pharmaceutical analysis, including direct enantiomeric separation and direct assay of drugs in plasma.
电动色谱（EKC）是毛细管电泳的一个分支，它允许通过电泳技术分离电中性溶质。EKC的分离原理基于色谱原理，并且随着分配机制的发展出现了各种EKC模式。胶束电动色谱（MEKC）是在毛细管区带电泳（CZE）中使用离子表面活性剂溶液代替缓冲溶液，且其浓度高于临界胶束浓度（CMC），在各种EKC模式中它已成为最受欢迎的技术。除了分离电中性或非离子型溶质外，MEKC对离子型溶质的分离也和CZE一样有效，因此它适合分析包括阳离子、阴离子和中性药物在内的各种药物。MEKC中的分离选择性可以通过改变缓冲液以及更换表面活性剂轻松调控。使用手性表面活性剂或手性添加剂可成功实现直接对映体分离。通过类似于胶束高效液相色谱的直接进样法，也成功实现了血浆中药物的测定。在本文中，我们总结了MEKC的原理、分离特性以及在药物分析中的一些应用，包括直接对映体分离和血浆中药物的直接测定。
