【作者】 杜开峰；

【导师】 孙彦；

【作者基本信息】 天津大学 ， 生物化工， 2008， 博士

【摘要】 色谱介质对于色谱分离至关重要,是实现有效分离的关键,开发、研制新型色谱介质具有重要的现实意义。因此,本论文以新型色谱介质的合成为主要研究内容,并深入研究了它们作为色谱介质的结构和性能研究。采用自制亚微米级硫酸钠颗粒为固体致孔剂,环己醇和十二醇为液体致孔剂,甲基丙烯酸缩水甘油酯及二甲基丙烯酸乙二醇酯分别为单体和交联剂,通过原位聚合法合成了一种高渗透性整体柱分离介质。经二乙胺修饰后,制备了阴离子交换模式的介质。与不加硫酸钠颗粒合成的整体柱相比,这种超大孔整体柱介质对蛋白质保持高吸附容量的同时,柱效及渗透性都有了很大的提高。在成功合成高渗透性整体柱的基础上,为了提高介质的吸附容量,在整体柱孔道表面接枝带有功能团的聚合物长链,经二乙胺修饰后,得到了触须式阴离子交换模式的介质。介质经过接枝后,动态吸附容量比接枝前提高了2倍多,并且吸附容量不受流速影响。由于亲水性聚合物长链的存在,使蛋白质的传质阻力增加,柱效略有降低,但仍然具有较高的渗透性,显示了良好的应用性能。采用溶胶-凝胶模板法,利用自制琼脂糖凝胶球为模板、异丙醇钛为钛源合成了多孔二氧化钛微球。并通过详细考察模板、矿化时间、矿化次数、煅烧温度等因素,获得最佳合成条件。然后,将合成的二氧化钛微球装柱,进行色谱性能测试,考察了其机械强度、柱效及分离性能。通过对二氧化钛微球的色谱性能评价,发现其能够对分子结构差异比较小的碱性化合物基线分离,并且峰对称性很好,表现了良好的分离性能。在此基础上,在琼脂糖凝胶球内引入碳酸钙颗粒,通过溶胶凝胶-固相反应法合成了大孔钛酸钙微球。合成反应中,碳酸钙颗粒既是大孔致孔剂,也是生成钛酸钙的一种反应原料。实验中,详细考察了碳酸钙含量和温度对大孔钛酸钙微球的机械强度、孔道分布及比表面积等的影响。选择优化条件下合成的大孔钛酸钙微球进行色谱测试,与二氧化钛介质比较,显示其对碱性化合物非特异性吸附低,具有作为色谱介质的良好潜力价值。更多还原

【Abstract】 The heart of a chromatographic separation process is the chromatographic media, and the key step to improve the separation technique is the development of chromatographic media. Therefore, the thesis focuses on the fabrication and characterization of novel media for chromatography.The details in this work are summarized as follows:A novel macroporous poly(glycidyl methacrylate-ethylene glycol dimethacrylate) monolith (MLS) was synthesized by in situ polymerization with customized solid granules of Na2SO4 and liquid solvent as co-porogen. After functionalized with diethylamine, an anion-exchanger monolith was obtained. Compared with the conventional monolith (ML) using organic solvents only as a porogen, the improved monolith (MLS) showed higher column efficiency and column permeability without obviously decreasing the dynamic binding capacity of protein. It is considered that the superpores introduced by the solid granules play an important role for the improvement of the monolith performance.To enhance the binding capacity of protein to the adsorbent, poly(glycidyl methacrylate-diethylamine) tentacles were grafted onto the pore surface of the macroporous monolith using ceric ammonium nitrate as a imitator. This further increased the dynamic binding capacity of BSA to 74.7 mg/ml, about three times higher than that of the monolith without the grafted tentacles. The grafted chains on the pore surface would hinder protein mass transfer, leading to the decrease of column efficiency. Despite this unfavorable effect, the grafted monolith still exhibited high permeability.Porous titania beads were synthesized by a sol-gel-templating method using agarose gel as template. The dipping time and repeated mineralization cycle played the important roles in the diffusion of the titanium precursors into templates and the maintenance of porous structure of the resultant titania beads. Calcination temperature affected the size and phase state of titania nanocrystals, specific surface area, pore volume and porosity. By control of these factors, it was possible to fabricate porous titania beads of 7 to 150μm in mean diameter. Larger-sized titania beads could be easily produced by using larger-sized agarose gel. Finally, flow hydrodynamics, column efficiency and separation performance were studied using the column packed with the optimized titania beads of 15μm. The results indicate that the porous titania beads had excellent mechanical stability, and the column exhibited high column efficiency and good separation performance of three aniline derivatives. Compared with other approaches to the fabrication of titania beads, the present strategy provides a readily controllable procedure for the preparation of well-defined beads of various sizes determined by the initial templates, so it may open a new way to the fabrication of well-defined inorganic beads with tailored properties for HPLC packings.Macroporous calcium titanate beads were fabricated through sol-gel mineralization of agarose gel entrapping calcium carbonate and subsequent heating treatment. In the reaction process, calcium carbonate was applied not only as porogen, but also as calcium source in the synthesis of calcium titanate material. The pore size distribution, porosity, specific surface area of final materials can be controlled by the temperature and content of calcium carbonate granules in the agarose gel. Finally, the optimized macroporous calcium titanate beads were investigated as chromatographic media. It exhibited good separation property and showed less nonspecific adsorption of basic compounds compared with titania beads.更多还原