Selectivity of guanidinium ionic liquid for capillary gas chromatography

A guanidinium ionic liquid,N,N,N′,N′-tetrabexyl-N″,N″-dimethylguanidinium bis(trifluoromethane)sulfonylimide(THDMGNTf2),was synthesized and used as stationary phase for capillary gas chromatography.In comparison with imidazolium ionic liquid stationary phase,the present new stationary phase exhibits quite different selectivity and behaves more like a low polar stationary phase.The guanidinium ionic liquid of THDMG-NTf2 exhibited better separation of Grob test mixture than irnidazolium ionic liquid of 1-octyl-3-butylimidazolium bis(trifluoromethane)sulfonylimide(OBIM-NTf2).Solvation parameter model was also used to evaluate the selectivity of THDMG-NTf2.Additionally,essential oil of Magnolia biondii Pamp was analyzed to further evaluate the selectivity of THDMG-NTf2 for a sample of complicated components.Satisfactory separation of the essential oil was achieved on a THDMG-NTf2 column(10 m)while using a commercial column(30 m)as reference.The present study shows that the guanidinium ionic liquid possesses novel chromatographic selectivity and has great potential for wide applications.