DEVELOPMENT OF HIGH PERFORMANCE TECHNIQUES FOR CHIRAL SEPARATION AND DETECTION BY CAPILLARY ELECTROPHORESIS-MASS SPECTROMETRY

点击翻译按钮获取中文摘要

The on-line coupling of capillary electrophoresis (CE) with mass spectrometry (MS), namely CE-MS, for the use in stereoselective separations and detection was investigated as a highly sensitive and selective detection scheme. Also basic research on enantiomer separations by capillary electrochromatography (CEC) and micellar electrokinetic chromatography (MEKC) using a novel chiral micelle were carried out along with a basic study on the highly sensitive analysis by MEKC-MS employing an on-line sample concentration technique.1.Chiral separations by CE-MS employing an electrospray ionization (ESI) interface and a partial filling technique were achieved by using a chiral crown ether as a chiral selector. Some UV-transparent compounds having a primary amino group were successfully enantioseparated and detected.2.Several phenylthiohydantoin-DL-amino acids and dansyl-DL-amino acids were optically resolved by MEKC with a newly synthesized chiral micelle, i.e., sodium N-decanoyl-N-methylglucamide.3.The use of two different types of capillaries in CEC was investigated for enantiomer separations. A packed capillary (100 μm i.d.) with an OD-type (Daicel, 3 μm) chiral packing and an open tubular capillary (20 μm i.d.) coated with avidin by adsorption were employed. Much higher efficiencies in enantioseparations with both capillaries were attained than the corresponding HPLC columns.4.To enhance the detection sensitivity in MEKC-MS employing an atmospheric pressure chemical ionization (APCI) interface, sweeping was applied as an on-line sample concentration technique. Several chiral herbicides, dialkyl phthalates, and aromatic amines were successfully separated and detected with 100 to 1000-fold enhancement in sensitivity compared to conventional MEKC-APCI-MS.