两性离子交换有机聚合物包覆硅球整体柱的制备及评价

利用甲基丙烯酸和2-二甲基乙基胺甲基丙烯酸酯为功能单体,乙二醇二甲基丙烯酸酯为交联剂,环己醇、甲醇和水为三元致孔剂,在内径为250μm石英毛细管内原位聚合制备了1种有机聚合物包覆硅球两性离子交换整体柱.通过对单体总浓度、致孔剂的组成和聚合反应时间的调节控制有机聚合物对硅球的包覆,并通过扫描电镜图和压力对流速关系曲线,确定了整体柱的最佳制备条件.最佳条件为单体总浓度T=25%、c=30%,致孔剂组成是环己醇∶甲醇∶水的体积比为8∶1∶1,反应时间为5h.从整体固定相的微观结构、抗压性、溶胀性、柱效和交换容量等方面对整体柱进行评价,认为该整体柱具有较好的抗压性、较高的柱效、较大的交换容量和很强的抗溶胀性.在此基础上,利用长度为4cm的整体柱在6min内分离了一组无机阴离子,在9min内分离了一组有机胺类阳离子.

Preparation and evaluation of a zwitterionic column containing silica micro-particles encapsulated in organic monolith

A zwitterionic column containing silica micro-particles encapsulated in organic monolith was prepared by in-situ polymerization of methacrylic acid,ethylene dimetharylate and 2-(dimethyl amino) ethyl methacrylate in a 250 μm i.d.fused silica capillary packed with silica micro-particles.The conditions of preparation were explored,the total concentration of the monomers,volumetric ratio of porogens and time was investigated by SEM and corroborated with back pressure measurements,and the optimal conditions for preparation of the column were established.The optimized concentration,volumetric ratio of porogens and time are T=25%(C=30%),8:1:1 and 5 h,respectively.The prepared column was evaluated in terms of micro-pore structure,endurance of pressure,permeability,ability of anti-swelling,ion-exchange capacity and column efficiency.The results demonstrated that the column is better in all the terms mentioned above than those of conventional organic monolithic column.Finally,the column was successfully used to fast baseline separate 4 inorganic anionic ions in 6 min and 3 organic amine cationic ions in 9 min.