The Research Of Improvement Of Reproducibility In Capillary Electrophoresis Characterization Of Chinese Traditional Medicine By Different Methods

Herbal medicines have been widely used for health needs over many centuries and become more and more popular worldwide during the last decade. In recently years, the quality control level of Tradition Chinese Medicine(TCM) has been improved notablybecause of the development of modern life science and analytical science. The most widely used methods for the separation of TCM are thin-layer chromatography, gas chromatography, high-performance liquid chromatography, infrared spectroscopy, nuclear magnetic resonance method and mass spectrometric analysis. At present, capillary electrophoresis(CE) has become popular for analyses of complex compounds of TCM for its great separating power. Under the optimum conditions, much information of TCM can be obtained by CE. A major drawback of CE is poor precision, and then the identifying of the complex compounds would be influenced. In this thesis, several methods have been introduced to improve the precision in CE analyses. They are the following ones:improvement of reproducibility in CE characterization of Rhubarb by normalization of migration time; improvement of reproducibility in capillary electrophoretic characterization of Radix Scutellariae by constant electrical current coupled with two-marker correction; migration time correctio in capillary electrophoresis by the electrical current monitoring coupled with the last peak in electropherogram. This thesis consists of three sections:Chapter one:In this chapter, the necessary of quality controlling of TCM was introduced. At the same time, discussion is made on the detection methods of TCM, the advantages of CE and its applying for the research of TCM, especially how to improve the reproducibility of CE.Chapter two:The principle of normalized migration time and its application on the traditional Chinese medicine (TCM) analysis by capillary electrophoresis (CE) were presented in this paper, It was the core of the normalization of migration time that the fluctuation of apparent migration velocity for each component at different runs was attributed to the difference of electroosmotic flow velocity. To transform migration time to normalized migration time, one peak in the ordinary electropherogram was selected as internal peak. One of the commonly used traditional Chinese medicines, Rhubarb, was chosen as a model to verify the advantage of normalization of migration time in improving reproducibility of CE. Both of the experiments, the micellar electrokinetic chromatography parallel experiments for Rhubarb extract and capillary zone electrophoresis experiments for samples prepared by mixing extract of Rhubarb with various solutions, showed that RSD(t')