| Summary: | 碩士 === 中國醫藥大學 === 藥學系碩士班 === 98 === Capillary electrochromatography (CEC) is a new and exciting hybrid separation technique that seeks to exploit the combined advantages of both capillary electrophoresis and high performance liquid chromatography and capillary electrophoresis. The subject of this study is to prepare two new types of open-tube epitaxial system synthetic capillary electrochromatography stationary phase, where nanoparticles were covalently immobilized in the column. The first column was synthesized by polymerization of methacrylamide and multi-wall carbon nanotubes with the initiators of N, N, N '', N''-tetramethylethylenediamine and ammonium perfulfate in the porogenic solvent, borate buffer (pH 8.1, 150 mM). The polymerization of methacrylamide, glycidyl methacrylate, and nano-Chitosan was initiated by azobisisbutyronitrile (AIBN) to complete the second column. The synthesized phases were characterized by ATR-IR, SEM, and electroosmotic flow profiles under the changes of pH values, concentrations and additions of organic modifier to the running buffers.
Besides optimizing CEC conditions, samples, including phenols, flavonoids, tetracyclines and chiral compounds, were analyzed with respect to velocity and retention factors to evaluate electrophoretic and chromatographic contributions to the CEC mechanism for each analyte. Phenols in the borate buffer (pH 8.60, 50 mM); flavonoids in the borate buffer (pH 8.82, 150 mM) add with ACN (10%, v/v); tetracyclines in the phosphate buffer (pH 2.86, 50 mM) separated by MA-CNT column. Tryptophans in the Tris buffer (pH 9.49, 100 mM); catechin in the phosphate buffer (pH 6.58, 50 mM) add with MeOH (80%, v/v); α-tocopherols in the borate buffer (pH 7.50, 10 mM)separated by MA-CS column. The migration rates of phenolic acids were determined by the electrophoretic mobilities of the various phenolate ions, such as π-π interactions, electrostatic effects, hydrogen bonding, and hydrophobic interactions. The retention factors were greater for flavonoids, which are polyphenolic, than for simple phenols, and the migration times were simutaneously affected by the electrophoresis and chromatography. A complete well-resolved separation of the cationic forms of tetracyclines and the enantiomer of chiral compounds, were acheived either by electrophoresis or by chromatography.
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