| 摘要: | 毛細管電層析 (capillary electrochromatography; CEC) 乃是結合高效液相層析法 (high performance liquid chromatography, HPLC) 與毛細管電泳法 (capillary electrophoresis, CE) 的操作特性之新分離系統。
本研究擬結合奈米粒子，合成一新型開管多孔層式毛細管電層析固定相管柱，其先在管壁鍵結methacrylamide (MA)，與多壁層奈米碳管(multi-wall carbon nanotube) 結合，形成MA-CNT管柱之固定相。另製備毛細管鍵結MA，在催化啟始劑AIBN (azobisisobutyronitrile) 結合奈米聚殼醣 (chitosan, CS) 與GMA (glycidyl methacrylate)，形成第二管柱之固定相。並使用衰減全反射紅外線光譜分析 (ATR-IR)、場發射掃描式電子顯微鏡 (SEM) 鑑定合成管柱之官能基，另以電滲流測試合成管柱在不同pH值、濃度與緩衝溶液添加修飾劑之表現。
除調整最佳毛細管電層析分析條件，分析物結構同樣影響分析速度因子 (velocity factors) 與遷移因子 (retention factors)，分析物各最佳條件為：酚類於50 mM硼酸緩衝液，pH 8.60；類黃酮於150 mM硼酸緩衝液，pH 8.82，添加10% (v/v) acetonitrile；四環素於50 mM磷酸緩衝液，pH 2.86得以分離。以及掌性化合物應用於奈米聚殼醣固定相，分析物各最佳條件為：色氨酸於100 mM之Tris緩衝液，pH 9.49；兒茶素於50 mM之硼酸緩衝液，pH 6.58，80% (v/v) methanol 修飾劑；與α-生育醇於100 mM之硼酸緩衝液，pH 7.50得以分離。多酚類化合物的遷移率取決於苯酚離子間作用，如π-π鍵相互作用、靜電作用、分子間氫鍵與疏水性之作用。類黃酮類化合物為簡單的多酚類化合物，遷移因子對分析物之毛細管電層析影響較大。陽離子四環素類抗生素之分離，以及掌性化合物之鏡像異構物於掌性固定像之毛細管電泳或毛細管電層析影響下皆可獲得良好的分離。
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. |
