| Capillary electrophoresis (CE), also known as high-performance capillary electrophoresis (HPCE), is widely used as a separation technique. Now they are applied widely in the analysis of biological specimens, medicines including traditional Chinese medicine and so on. The content of effective constituents in traditional Chinese medicine affects the curative ability directly. Thus it is significant to determine the contents of effective constituents in Chinese medicine. Amino acids are essential nourishment to creatures and they are the smallest units of proteins. So, to determine the contents of amino acids in foods is also significant by the means of capillary electrophoresis.There are four chapters in this paper.In the first chapter, the related research report about this thesis was reviewed, including the description of the research progress, the separation modes of CE, detection modes. The chapter also describes the cetate-coated porous polymer joint in capillary electrophoresis applications, sample derivation method and so on.In the second chapter, a cellulose acetate-coated porous polymer joint in capillary with amperometric detection was used to separate the effective constituents in catechu. Using the cellulose acetate membrane interface, the side effect of high voltage on ampere detection could be reduced greatly. So capillary with larger inner diameter could be used to improve the injection amount and detection sensitivity. Cellulose combine has many advantages, such as easy fabrication, durable, easy combination with self-assembled devices and so on. This device of CE was very simple and low cost. Use this device to detect the constituent of catechu. In 15mM borax buffer solution (pH 10.2), five flavonoids could be completely separated within 12 min. The detection limits (S/N= 3) of flavonoids were in the range of 3.2-5.4×10-7 mol/L. The recoveries ranged form 80% to 120% that implicated a satisfactory result.In the third chapter, we used capillary electrophoresis with electrochemical detection to detect active ingredients of flavonoids in some traditional Chinese medicine. A sensitive technique of capillary electrophoresis for the determination of eight kinds of flavonoids (rutin, quercetrin, quercetin, kaempferol, kaempferide, catechin, apigenin and luteolin) was established. A graphite electrode was used as the working electrode and the separation and detection conditions were optimized. In 18mM borax buffer solution (pH 10.2), eight flavonoids were complete separated quickly. The detection limits (S/N=3) of flavonoids were in the range of 4.6-8.5×10-7 mol/L. The method was used to detect flavonoids of Hippophae fhamnoides L, Hypericum perforatum, Platycladus orientalis and Aster tataricus finally. The recoveries for these flavonoids were between 80% and 120% that implicated a satisfactory result.In the fourth chapter, high-speed separation and detection of amino acids in laver with a short capillary electrophoresis system was described. This high capillary electrophoresis can improve the separation efficiency, because of the small injection, shorter capillary length, and high separation voltage. Micellar electrokinetic chromatography was used to separate amino acids. Under separation voltage 3.0 kv, the ten amino acids could be completely separated within 3min in 10 mol/L Na2HPO4-NaOH buffer (pH=11.5) including 30 mmol/L sodium dodecyl sulphate (SDS). The results showed a good linear relationship between concentrations and peak heights. The detection limits were between 25 and 80 nmol/L. Lastly, the method was successefully applied to the separation and determination the amino acids in the laver. |
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