Synthesis and Application of Leucine-Based Ionic Liquids as Stationary Phases in Gas Chromatography

A study on the leucine-based ionic liquids as stationary phases in gas chromatography was presented. L-Leucine ethyl ester tetrafluoroborate and L-leucine ethyl ester bis [(trifluoromethyl) sulfonyl] imide were synthesized and used as stationary phases in gas chromatography. Meanwhile, Abraham solvation parameter models at 50, 80 and 110℃ were used to evaluate the solvation characteristics. Furthermore, the chromatographic separation performance was evaluated by a Grob test mixture and n-alkanes mixture. The present results demonstrate that the leucine-based ionic liquids stationary phases have good film-forming ability. The system constants indicated that the dipolarity/polarizability and the hydrogen-bond interaction play a major role among five molecular interactions between stationary phases and solute molecules. Leucine-based ionic liquids stationary phases possess excellent chromatographic separation performance, and may be applicable as valuable gas chromatography stationary phases.