建立了一种快速评价和筛选离子液体的比较气相色谱方法,以各离子液体系列中研究最多的离子液体为参比固定液,装填成参考柱,以新设计合成的离子液体为样品固定液,装填成样品柱。以正己烷、乙酸乙酯、苯、2-戊酮、吡啶、丁醇和1-硝基甲烷7种溶剂作为探针分子,采用调整保留时间和不对称因子为考察指标,能够有效地筛选出满足应用的离子液体。
Analytical chemists learn the polarity of chromatographic stationary phase by testing the Rohr-schneider-McReynolds constants in chromatographic columns, while chemical engineers acquire the selectivity and solubility of solvents by determining solubility parameters. However, in evaluating the properties of ionic liquids, they are not as useful as in general solvents. Sometimes the probe molecules have no peaks, and sometimes the solubility parameters calculated are not as what we predict. In order to overcome the shortages of the existing methods, a comparative chromatographic method was established, in which a well-known ionic liquid was used as a reference stationary liquid into the reference column, and new design ionic liquids as a sample stationary liquid filling into the sample column. With 7 solvents( n-hexane, ethyl acetate, benzene, 2-ketone, pyridine, n-butanol and nitro propane) as probe molecules, the adjusted retention time and asym-metry factor as the index, the target ionic liquids can be selected.