Evaluation Of Bis(Trifluoromethane) Sulfonimide Ionic Liquid Stationary Phase For Gas Chromatography

With the development of science and technology,gas chromatography has become an important separation and analysis technology,which plays a vital role in many aspects,including petrochemical,medical and health,environmental monitoring,biochemistry,food testing and other fields.Ionic liquids are a class of organic substances composed of anions and cations that remain liquid at room temperature.They have physicochemical properties such as low vapor pressure,low melting point,high thermal stability,and high viscosity.They have specific intermolecular forces on different compounds,and are anion and cation ionic structure can be designed.These excellent characteristics make ionic liquids have good prospects for gas chromatography stationary phases.Based on this,ionic liquids were modified in this thesis.Synthesizes two ionic liquid stationary phases containing silane groups,and investigates their chromatographic properties.The main summary is as follows:Silicane imidazolium ionic liquids（ILs） with different alkyl substituted groups（C1,C2and C4）on the cations and bis（trifluoromethane）sulfonimid ions（[NTf₂]^-）as the anions were synthesized as the stationary phase for packed column gas chromatography.The silicane-based imidazolium ILs were strong polar stationary phases.The cation structure influenced the t hermal stability,polarity and separation properties.The separation behavior of 1-butyl-3-[（3-trimethoxysilyl）-propyl]imidazolium bis（trifluoromethane）sulfonimide（[PBIM][NTf₂]）is better than that of other IL stationary phases.The[PBIM][NTf₂]stationary phase was further evaluated using solvation parameter model.The interaction mechanism between stationary phase and components as well as separation properties of[PBIM][NTf₂]column for different chemical compounds were investigated.The results indicated that hydrogen-bond basicity and dipole-dipole interactions as the main intermolecular forces existed between[PBIM][NTf₂]and components.The stationary phase revealed a good selectivity for the components such as grob test mixture,alkanes,alcohols,esters and amines.Silicane imidazolium dicationic ionic liquids（DILs） with different silicane imidazolium groups on the cations and bis（trifluoromethane）sulfonimid ions（[NTf₂]^-）as the anions were synthesized as the stationary phase for capillary column gas chromatography.Thermogravimetric,Mc Reynolds constant,and Abraham solvation parameter models were used to study the thermal stability of the stationary phase and the interaction mechanism between the stationary phase and the solvent molecules.Investigate the separation of Grob reagents,alkanes,alcohols,aromatics,and amines on the column to explored the separation performance of the column.The results indicated that the two stationary phases have good thermal stability and are strongly polar stationary phases;Hydrogen bonding basicity and dipole-dipole interaction are the main forces existing between the stationary phase and solute molecules;Different polarities and different types of sample components were well separated on[MM（bim）₂][（NTf₂）₂];The silane-based imidazole dicationic ionic liquids stationary phase has great potential for separation of complex sample components at high temperatures.