Ionic liquids (ILs) are a class of molten salts with melting points below 100 °C. Their unique properties including high thermal stability, wide viscosity range, negligible vapor pressure under room temperature, and the capability of undergoing multiple solvation interactions make them ideal candidates as gas chromatography (GC) stationary phases and sorbent coatings in solid-phase microextraction (SPME). The first part of this dissertation includes an introduction of ionic liquids and their applications as GC stationary phases. The following chapters in this part introduce various example of utilizing ILs as GC stationary phases. Functionalized ILs containing different functional groups and tris(pentafluoroethyl)trifluorophosphate (FAP) anion have been characterized using the solvation parameter model and applied as selective GC stationary phases. A total of fifteen ILs are examined on the basis of multiple solvation interactions. The effect of cation functional group, cation type, and counter anion has been thoroughly evaluated. The binary mixtures consisting of two PILs have been employed as highly selective GC stationary phases. The effects of PIL composition on the bleed temperature, system constants, and separation selectivity are examined.
PILs have been proven to be an ideal class of SPME sorbent coatings with promising thermal stability, extraction efficiency, and selectivity. The second part of this dissertation begins with an introduction of the application of ILs and PILs as sorbent coatings in SPME. Two chapters are then presented describing the design, synthesis, and application of two different types of PILs as sorbent coatings in SPME for the selective extraction of CO2. The presence of functional groups within the PILs results in different mechanism of CO2 capture. The analytical performances of the PIL fibers are evaluated and compared to that of the commercial fibers. The PIL-fibers and a selected commercial fiber are applied for the selective extraction of CO2 from simulated flue gas. The effects of humidity and temperature on the performance of different SPME fibers are discussed. The PIL-fiber exhibits superior CO2/CH4 and CO2/N2 selectivity to that of the commercial fiber. The final chapter introduces the development of a rapid and convenient analytical method for monitoring the enantiomeric purity of chiral molecules in IL-solvents, using headspace SPME coupled to chiral GC. Two commercial fibers as well as a PIL-based fiber are examined, and the analytical performance of the developed method is thoroughly evaluated. The developed method is successfully applied to the enantiomeric excess determination from selected mixtures of chiral molecules.