DEVELOPMENT OF HIGHLY SENSITIVE AND RAPID SEPARATION-DETECTION SYSTEM FOR ENVIRONMENTAL POLLUTANTS BY CAPILLARY ELECTROPHORESIS

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The aim of this project was to develop a highly sensitive and rapid analysis system for environmental pollutants by using capillary electrophoresis (CE), including micellar electrokinetic chromatography (MEKC) using on-line sample concentration techniques for enhancing the detection sensitivity and CE using mass spectrometry (MS) as a high performance detection scheme.1. Optimization of separation and detection conditions in an on-line sample concentration-MEKC system was carried out for several model compounds, such as dioxins, dialkyl phthalates, aromatic amines, and chiral pesticide components. As a result, the ten to thousands-fold increase in sensitivity was attained compared to conventional MEKC system.2. Combination of sweeping, an on-line sample concentration method, with MEKC-MS employing an atmospheric pressure chemical ionization (APCI) interface was investigated. Several hundreds-fold increase in detection sensitivity was obtained for dialkyl phthalates and organic amines compared with conventional MEKC-APCI-MS system.3. Fundamental studies on MEKC using synthesized ionic high molecular-mass surfactants (HMMSs) were carried out. Several polycyclic aromatic hydrocarbons were successfully separated with an HMMS solution containing large amount of organic modifiers.4. The change in peak profile during sweeping was successfully observed by using microchip electrophoresis (MCE) and the mechanism of sweeping was interpreted.5. A study on on-line combination of MCE with an MS detection (MCE-MS) was carried out using electrospray ionization as an interface. The use of a short capillary attached to the edge of the microchip as a spray nozzle was found to be effective for a stable ESI.