Sun Min, Feng Juanjuan, Chen Wenjie, Li Leilei, Duan Huimin, Luo Chuannan
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan, China.
J Sep Sci. 2014 Jun;37(11):1283-8. doi: 10.1002/jssc.201400001. Epub 2014 Apr 13.
The anionic part of ionic liquids can provide additional interactions during chromatographic separations. In this work, the chromatographic separation performance of a silica column functionalized with 1-propyl-3-methylimidazolium chloride ionic liquid was improved by in situ anion-exchange from chloride anions to dodecyl sulfonate anions and dodecylbenzene sulfonate anions. The separation performances of these ionic liquid functionalized phases were investigated and compared with each other using polycyclic aromatic hydrocarbons, phthalates, parabens, and phenols as model compounds. Results indicated that the new columns presented a better chromatographic separation than the original one. This was ascribed retention mechanism from organic anions. The introduction of dodecyl sulfonate anions increased the hydrophobicity of stationary phase. Furthermore, the phenyl groups of dodecylbenzene sulfonate anions could provide an enhanced selectivity to aromatic compounds such as polycyclic aromatic hydrocarbons by π-π interactions. Analysis repeatability of the new columns was satisfactory (RSD of retention time, 0.10-0.40%; RSD of peak area, 0.66-0.84%).
离子液体的阴离子部分在色谱分离过程中可提供额外的相互作用。在本工作中，通过将氯离子原位阴离子交换为十二烷基磺酸根阴离子和十二烷基苯磺酸根阴离子，改善了用1-丙基-3-甲基咪唑氯盐离子液体功能化的硅胶柱的色谱分离性能。以多环芳烃、邻苯二甲酸酯、对羟基苯甲酸酯和酚类为模型化合物，研究并比较了这些离子液体功能化固定相的分离性能。结果表明，新柱比原柱具有更好的色谱分离效果。这归因于有机阴离子的保留机制。十二烷基磺酸根阴离子的引入增加了固定相的疏水性。此外，十二烷基苯磺酸根阴离子的苯基可通过π-π相互作用对多环芳烃等芳香族化合物提供增强的选择性。新柱的分析重复性令人满意（保留时间的相对标准偏差为0.10 - 0.40%；峰面积的相对标准偏差为0.66 - 0.84%）。
