Quirino Joselito P
Australian Centre for Research on Separation Science, School of Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia.
J Chromatogr A. 2009 Jan 9;1216(2):294-9. doi: 10.1016/j.chroma.2008.11.062. Epub 2008 Nov 30.
The direction of the effective electrophoretic mobility of small organic cations in micellar electrokinetic chromatography using sodium dodecyl sulphate in a low-pH electrolyte can be reversed in the presence of organic solvent. This effective electrophoretic mobility change is presented here as a new dimension for on-line sample preconcentration of cations in capillary zone electrophoresis (CZE) using a background solution (BGS) modified by an organic solvent. The sample is prepared in a micellar solution without organic solvent. The focusing effect relies on the reversal in the effective electrophoretic mobility at the boundary zone between the micellar matrix and the BGS modified with organic solvent. This on-line sample preconcentration technique, called micelle to solvent stacking (MSS) afforded more than an order of magnitude improvement in concentration sensitivity compared to typical CZE-UV or CZE-electrospray ionization (ESI) MS analysis. The calculated limit of detection (S/N=3) for pindolol and metoprolol analysed by MSS-CZE-ESI-MS was found to be 0.03 and 0.01 microg/mL, respectively.
在低pH值电解质中使用十二烷基硫酸钠的胶束电动色谱法中，小有机阳离子有效电泳迁移率的方向在有机溶剂存在下可能会发生逆转。这种有效电泳迁移率的变化在此被视为利用有机溶剂改性的背景溶液（BGS）在毛细管区带电泳（CZE）中对阳离子进行在线样品预富集的一个新维度。样品在不含有机溶剂的胶束溶液中制备。聚焦效应依赖于在胶束基质与用有机溶剂改性的BGS之间的边界区域有效电泳迁移率的逆转。这种在线样品预富集技术，称为胶束到溶剂堆积（MSS），与典型的CZE-UV或CZE-电喷雾电离（ESI）MS分析相比，浓度灵敏度提高了一个多数量级。通过MSS-CZE-ESI-MS分析的吲哚洛尔和美托洛尔的计算检测限（S/N = 3）分别为0.03和0.01μg/mL。
