MICELLAR ELECTROKINETIC CHROMATOGRAPHY-MASS SPECTOMETRY FOR HIGH SENSITIVE QUANTITATIVE AND QUALITATIVE DETECTION OF NEUTRAL ANALYTES

胶束电动毛细管电泳色谱(MEKC)是毛细管电泳法(CE)的一种，能够通过电泳法分离中性分析物。毛细管区带电泳(CZE)的分离原理是在毛细管区带电泳(CZE)的运行液中加入离子表面活性剂，其分离原理是分析物在离子胶束和周围水相之间的分配。运行溶液中表面活性剂的存在给质谱学检测带来了问题，因为大量的表面活性剂降低了CE和MS之间的电喷雾电离(ESI)界面的电离效率，而ESI界面是CE-MS唯一的商业可用界面。基于毛细管中不连续运行的溶液之间分析物的迁移率的差异，开发了几种在线样品浓缩技术来提高毛细管电泳法的浓缩灵敏度，但…更重要的是，这些技术不适用于中性分析物，因为它们不具有电泳性。本研究的目的是开发一种高灵敏度的定量和定性检测方法--MEKC中的质谱学检测技术。这项研究的另一个目的是开发在线样品浓缩技术，以提高大多数检测方法的检测灵敏度。为了开发MEKC-MS，一种配备了专门设计的大气压化学电离(APCI)接口的MS仪器，其效率不受显著高浓度表面活性剂的存在的影响，另一种配备了ESI接口的新型MS仪器被使用。如果使用几种技术优化条件，MEKC-MS可以用于几种不同的分析物，但包括仪器在内的技术必须进一步发展，以便于操作。MEKC的在线样品浓缩非常成功：一种名为“扫掠”的新浓缩技术可以将检测灵敏度提高3-5个数量级以上，具体取决于分析物与胶束的亲和力。将开发在线样品浓缩技术与MEKC-MS相结合，以提高MS的检测能力。较少

Micellar electrokinetic chromatography (MEKC) is a mode of capillary electrophoresis (CE) and is capable of separating neutral analytes by electrophoresis. MEKC is performed simply by adding ionic surfactant to the running solution of capillary zone electrophoresis (CZE) and its separation principle is based on the partitioning of the analytes between the ionic micelle and the surrounding aqueous phase. The presence of the surfactant in the running solution causes problems in mass spectrometric detection, because the significant high concentration of the surfactant deteriorates the ionization efficiency of the electrospray ionization (ESI) interface between CE and mass spectrometry(MS), which is the only one commercially available interface for CE-MS. Several on-line sample concentration techniques have been developed to improve concentration sensitivity in CZE on the basis of the difference in mobilities of the analytes between the discontinuous running solutions in the capillary, but … More these techniques are not applicable to neutral analytes because they do not have electrophoretic mobility. The purpose of this research is to develop techniques for mass spectrometric detection in MEKC as a high sensitive quantitative and qualitative detection method. Another aim of the research is to develop on-line sample concentration techniques if MEKC to improve detection sensitivity in most detection methods. To develop MEKC-MS, a MS instrument equipped with a specially designed atmospheric pressure chemical ionization (APCI) interface, which efficiency is not affected by the presence of significantly high concentration of the surfactant, another new MS instrument equipped with ESI interface were utilized. MEKC-MS was possible for several different analytes if the conditions are optimized by using several techniques, but the technique including instruments must be further developed for easy operation. On-line sample concentration in MEKC was very successful : a new concentration techniques named "sweeping" can enhance the detection sensitivity more than 3 to 5 orders of magnitude in terms of peak heights depending on the affinity of the analytes with the micelle. The combination of the on-line sample concentration techniques and MEKC-MS will be developed to improve the detectability of MS detection. Less