School of Science, Qingdao Technological University, Qingdao, China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2011 Jun 1;879(19):1641-6. doi: 10.1016/j.jchromb.2011.03.061. Epub 2011 Apr 9.
A novel two-dimensional (2D) separation method, which hyphenated micellar electrokinetic capillary chromatography (MEKC) and capillary zone electrophoresis (CZE), was developed for analysis of flavonoids in Leonurus cardiaca. The Leonurus cardiaca sample was separated and purified in first dimension by MEKC. Then only a selected portion of the first dimension separation was transferred into the second dimension by pressure. Finally, the zone of flavonoids was separated by CZE. As the key to successful hyphenation of MEKC and CZE, an analyte focusing by micelle collapse (AFMC) concentration method was employed between the two dimensions to release analytes from the micelle interior to a liquid zone and to overcome the sample zone diffusion caused by mobilization pressure. The whole heart-cut 2D separation process can be performed in a conventional CE analyzer. The relative standard deviation of peak height, peak area and migration time were in the range of 2.3-4.2%, 1.5-3.8% and 3.6-5.5%, respectively, and detection limits (S/N=3) were 15-55 ng/mL. The new methodology was applied with success for the flavonoids separation of Leonurus cardiaca.
建立了一种新颖的二维（2D）分离方法，将胶束电动毛细管色谱（MEKC）和毛细管区带电泳（CZE）联用，用于分析益母草中的黄酮类化合物。益母草样品首先通过 MEKC 在第一维上进行分离和纯化。然后通过压力将第一维分离的选定部分转移到第二维。最后，通过 CZE 分离黄酮区带。为了成功实现 MEKC 和 CZE 的联用，在二维之间采用胶束崩溃的分析物聚焦（AFMC）浓缩方法，将分析物从胶束内部释放到液相中，并克服由迁移压力引起的样品区扩散。整个全切 2D 分离过程可以在常规 CE 分析仪中进行。峰高、峰面积和迁移时间的相对标准偏差分别在 2.3-4.2%、1.5-3.8%和 3.6-5.5%范围内，检测限（S/N=3）为 15-55ng/mL。该新方法成功地应用于益母草中黄酮类化合物的分离。
