原位聚合法制备碳十八甲基丙烯酸酯聚合物及其用作开管毛细管电色谱固定相

以十八碳醇甲基丙烯酸酯为单体、乙二醇二甲基丙烯酸酯为交联剂,采用原位聚合法合成了一种新型毛细管开管柱固定相,优化了毛细管开管柱的制备参数。柱内表面的电镜图像显示其具有多孔皱褶、质地均匀的结构特征。将其应用于甲苯、乙苯、丙苯、丁苯、戊苯和己苯的分离试验中,6种化合物达到了完全分离,出峰顺序与它们的疏水性一致,表明该柱有明显的疏水色谱作用。在10 mmol/L磷酸盐(pH 8.5,含50%(v/v)乙腈)流动相、16 kV电压下,该开管柱成功地分离了4种抗癫痫类药物,柱效范围为35300~49800 塔板/m,与空柱管相比分离效果明显提高。结果表明通过本实验的原位聚合法可制备具有反相色谱作用的有机基质碳十八开管毛细管电色谱柱。

Preparation of octadecyl methacrylate-based polymer stationary phase by in-situ polymerization for open tubular capillary electrochromatography

The preparation of porous polymethacrylate-based open tubular capilary columns by in-situ copolymerization of octadecyl methacrylate (OMA), and ethylene dimethacrylate (EDMA) in N,N-dimethylformamide (DMF) solvent are proposed. The parameters of the preparation procedure of the stationary phase are discussed in detail. The surface of the cross-section of an open tubular (OT) column by scanning electron microscope (SEM) showed wrinkle configuration, which is expedient to enhance proportion of stationary phase and column capacity. Efficient separation of six alkyl benzene homologous series (namely, toluene, ethylbenzene, propylbenzene, butylbenzene, amylbenzene and hexylbenzene) were performed by CEC using the prepared column, and their elution order was in agreement with their hydrophobicity. So, the OT columns bonded with octadecyl ligands yielded reversed-phase retention behavior toward nonpolar solutes. In addition, the separation of four antiepileptics was also investigated with satisfactory effectiveness. The column efficiency range was 35300-49800 plates/m. The results showed that the C₁₈-OT column of organic matrix for reversed-phase chromatography was successfully prepared via in-situ polymerization in this work. Hereby, this new column thus offers a promising new alternative in OT-CEC and will be useful in separation science.