一种新型超支化聚酯物理吸附涂层毛细管电泳柱的制备及其对碱性蛋白质的分离

Preparation of Capillary Electrophoresis Column Physically Coated with Hyperbranched Polyesters and Its Application in the Separation of Basic Proteins

采用一步法和准一步法合成了以季戊四醇为核的两个系列的超支化聚酯，利用红外光谱、羟值测定等手段对分子结构进行了表征。利用超支化聚合物低粘度的特点，用物理吸附方法将其涂于毛细管电泳柱内壁，使其在毛细管内壁上形成稳定的超支化聚酯涂层。该涂层在pH3．0～7．0范围内能够有效地抑制电渗流和蛋白质在毛细管壁上的吸附，在pH5．0的缓冲液中分离碱性蛋白质时，分离柱效可达10^5塔板／m，具有良好的分离效果。

Two series of hyperbranched polyesters were synthesized using pentaerythritol as the core by one-step and pseudo-step procedures. The molecular structures of the hyperbranched polyesters were characterized using infrared spectrum and hydroxyl value. Due to their low viscosity, the hyperbranched polyesters were easily coated on the inner surface of the fused-silica capillary by physical adsorption. The adsorption behavior of this capillary electrophoresis column coated with polyesters was investigated by the separation of three basic proteins. The electro-osmotic flow and the capability for the separation of the basic proteins were studied. It was found that the coatings of hyperbranched polyesters could significantly reduce the electro- osmotic flow and suppress the protein adsorption onto the inner surface of the fused-silica capillaries in the pH range of 3.0 - 7.0. Three basic proteins were effectively separated at pH = 5 on the column coated with the hyperbranched polyesters, with the separation efficiency being 10^5 plates/m. The experimental results also showed that the separation efficiency and the resolution on columns coated with hyperbranched polyesters by pseudo-step procedure were much better than those by one-step procedure.