[Evaluation of two hydroxyl-terminated monocationic ionic liquid stationary phases with high thermal stability for capillary gas chromatography].
Novel hydroxyl-terminated ionic liquids of 1-(6-hydroxyhexyl)-3-butyl imidazolium bis(trifluoromethyl) sulfonylimide (HHBIM-NTf2) and 1-(8-hydroxyoctyl) -3-butyl imidazolium bis(trifluoromethyl) sulfonylimide (HOBIM-NTf2) were synthesized as stationary phases for capillary gas chromatography (GC). Besides, 1-octyl-3-butyl imidazolium bis(trifluoromethyl) sulfonylimide (OBIM-NTf2) was used as the reference. Selectivities and thermal stabilities of HHBIM-NTf2, HOBIM-NTf2 and OBIM-NTf2 were evaluated by means of the separation of Grob test mixture and positional isomers after the columns were conditioned up to 160 degrees C, 250 degrees C and 300 degrees C, respectively. As a result, baseline separations of Grob test mixture and alcohol mixture and better peak shapes were observed with HHBIM-NTf2 and HOBIM-NTf2. Importantly, baseline separation of dimethoxybenzene isomers was also achieved with HHBIM-NTf2 and HOBIM-NTf2. Satisfactory selectivity of HHBIM-NTf2 still remained even after conditioned at 300 degrees C for 8 h. The results for thermal stability showed that as GC stationary phases, HHBIM-NTf2 and HOBIM-NTf2 were stable at least up to 300 degrees C and 250 degrees C, respectively. The hydroxyl-terminated monocationic ionic liquids possess excellent selectivity and thermal stability and are alternative candidates for GC stationary phases.
Department of Chemistry, School of Science, Beijing Institute of Technology, Beijing 100081, China.
Kai
K
Lu
Wei
W
Liu
Meiling
M
Qi
Yan
Y
Li
Ruonong
R
Fu
D002849:Chromatography, Gas / Q000295:instrumentation* / Q000379:methods; D005069:Evaluation Studies as Topic; D017665:Hydroxyl Radical / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*
D052578:Ionic Liquids; D012997:Solvents; D017665:Hydroxyl Radical