Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

8-12-2003

Journal or Book Title

Analytical Chemistry

Volume

75

Issue

18

First Page

4851

Last Page

4858

DOI

10.1021/ac0345749

Abstract

Room-temperature ionic liquids are a class of nonmolecular ionic solvents with low melting points. Their properties have the potential to be especially useful as stationary phases in gas−liquid chromatography (GLC). A series of common ionic liquids were evaluated as GLC stationary phases. It was found that many of these ionic liquids suffer from low thermal stability and possess unfavorable retention behavior for some classes of molecules. Two new ionic liquids were engineered and synthesized to overcome these drawbacks. The two new ionic liquids (1-benzyl-3-methylimidazolium trifluoromethanesulfonate and 1-(4-methoxyphenyl)-3-methylimidazolium trifluoromethanesulfonate) are based on “bulky” imidazolium cations with trifluoromethanesulfonate anions. Their solvation characteristics were evaluated using the Abraham solvation parameter model and correlations made between the structure of the cation and the degree to which the ionic liquids retain certain analytes. The new ionic liquids have good thermal stability up to 260 °C, provide symmetrical peak shapes, and because of their broad range of solvation-type interactions, exhibit dual-nature selectivity behavior. In addition, the ionic liquid stationary phases provided different retention behavior for many analytes compared to a commercial methylphenyl polysiloxane GLC stationary phase. This difference in selectivity is due to the unique solvation characteristics of the ionic liquids and makes them very useful as dual-nature GLC stationary phases.

Comments

Reprinted (adapted) with permission from Analytical Chemistry 75 (2003): 4851, doi: 10.1021/ac0345749. Copyright 2003 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Share

COinS