Department of Chemistry, Soochow University, 70 Linhsi Road, Shihlin, 11102 Taipei, Taiwan.
Department of Chemistry, Soochow University, 70 Linhsi Road, Shihlin, 11102 Taipei, Taiwan.
Talanta. 2018 Sep 1;187:73-82. doi: 10.1016/j.talanta.2018.05.013. Epub 2018 May 3.
In this study, we applied 1-vinylimidazole (VIM) as the functional monomer to prepare a series of VIM-based monolithic stationary phases for both reversed-phase and hydrophilic interaction capillary liquid chromatography (LC) using various dimethacrylates (EDMA: ethylene dimethacrylate; HDDMA: 1,6-hexanediol dimethacrylate; DDDMA: 1,10-decanediol dimethacrylate) as cross-linkers. With a simple thermally initiated free-radical cross-linking polymerization process, VIM-based monolithic stationary phases have been successfully prepared. The porosity, permeability, and column efficiency of synthesized VIM-based monolithic stationary phases were characterized. With similar total porosity (85-90%), the VIM-HDDMA monoliths showed the lowest permeability among the three sets of VIM-based stationary phases. Various sets of non-polar (alkyl benzenes and polycyclic aromatic hydrocarbons) and polar analytes (phenol derivatives and amphenicol antibiotics) were applied as model compounds to further investigate the retention behavior of the VIM-based monolithic stationary phases for reversed-phase capillary LC analysis using selected VIM-based monolithic columns. While a mixture of organic acids was employed to perform HILIC analysis using the selected VIM-based monolithic columns. The separation selectivity and retention behavior of the VIM-based monolithic stationary phases were compared to those obtained using three previously prepared alkyl methacrylate-based monolithic columns. Strong retention and good resolution of polar analytes (such as phenol derivatives, amphenicol antibiotics, and organic acids) were observed using the selected VIM-based monolithic columns. The strong retention and good resolution might be attributed to the additional hydrogen-bonding between the hydrogen-donating analytes and the hydrogen-accepting imidazolium functionality on the VIM-based stationary phase. The applicability for both reversed-phase and HILIC capillary LC analysis has also been demonstrated using the selected VIM-based monolithic columns.
在这项研究中，我们应用 1-乙烯基咪唑（VIM）作为功能单体，使用各种二甲基丙烯酸酯（EDMA：乙二醇二甲基丙烯酸酯；HDDMA：1,6-己二醇二甲基丙烯酸酯；DDDMA：1,10-癸二醇二甲基丙烯酸酯）作为交联剂，为反相和亲水相互作用毛细管液相色谱（LC）制备了一系列基于 VIM 的整体固定相。通过简单的热引发自由基交联聚合过程，成功制备了基于 VIM 的整体固定相。合成的基于 VIM 的整体固定相的孔隙率、渗透性和柱效进行了表征。在三组基于 VIM 的固定相中，VIM-HDDMA 整体具有相似的总孔隙率（85-90%），但具有最低的渗透性。各种非极性（烷基苯和多环芳烃）和极性分析物（苯酚衍生物和安普青霉素抗生素）被用作模型化合物，进一步研究了 VIM 基整体固定相在反相毛细管 LC 分析中的保留行为，使用选定的 VIM 基整体柱。而使用选定的 VIM 基整体柱进行亲水相互作用分析时，采用了有机酸混合物。与之前制备的三种烷基甲基丙烯酸酯基整体柱相比，比较了 VIM 基整体固定相的分离选择性和保留行为。使用选定的 VIM 基整体柱观察到极性分析物（如苯酚衍生物、安普青霉素抗生素和有机酸）的强保留和良好的分辨率。强保留和良好的分辨率可能归因于供氢分析物与 VIM 基固定相上的氢键供体功能之间的额外氢键。使用选定的 VIM 基整体柱也证明了其在反相和 HILIC 毛细管 LC 分析中的适用性。
