Application Of Highly Efficient Cyclic Olefin Copolymer Microchip Electrophoresis

Microchip electrophoresis is a miniaturized analytical technique with rapid separation speed and high separation efficiency. But its application in real analysis is quite limited because of the high cost of chip fabrication, it has not been a practical method yet. In order to promote the practical application of microchip electrophoresis, cheap COC microchips combined with low-cost programmable high voltage power supplies and laser induced fluorescence detectors were used in our work for the analysis of some analytes with practical importance. There are four chapters in this thesis.Chapter1:The μ-TAS was reviewed comprehensively. The development history of microfluidic chips, chip materials and production technologies, surface modification of microchannels, detection methods and the application of microchip-based electrophoresis in real samples were summarized.Chapter2:A fast and efficient microchip electrophoretic method for the analysis of banned aromatic amines was established. Because some aromatic amines are strongly toxic and even carcinogenic, it is highly necessary to detect them rapidly. In this work,5banned aromatic amines that were labeled with fluorescein isothiocyanate could be baseline separated within90s by using10mmol/L borax containing2%(w/v) hydroxypropyl cellulose (HPC) as the running buffer. The limits of detection were in a range of1-3nmol/L and the theoretical plate numbers were in a range of6.8-8.5×105/m. The method was successfully applied in the analysis of these banned aromatic amines in waste water and textile samples, recoveries of added standards were85-110%.Chapter3:A electrophoretic method using plastic microchips combined with low-cost laser-induced fluorescence detector was established to indirectly determinate sudan dyes, a group of dyes that are banned for use as food colorants due to their carcinogenicity. Because Sudan dyes can be reduced to aromatic amines and naphthalene phenolic derivatives, two methods of chemical reduction of Sudan dyes were adopted in this study. The aromatic amines from the dyes were labled by fluorescamine and were separated and detected with microchip electrophoresis with a405nm laser induced fluorescence detector. The experimental results showed that the reductive products could be baseline resolved within60s.Chapter4:A microchip electrophoresis based method for fast and efficient separation and detection of oxidized and reduced glutathione was established. Using HPC as additive for dynamic modification of the microchannels of COC microchips, fluorescamine labeled oxidized and reduced glutathione could be baseline separated in30s. The number of theoretical plates is up to1.0×106/m. The method is simple, rapid and reproducible, and were successfully used for the detection of glutathione in human serum sample.