Development of High Performance Liquid Chromatography Compatible Microextraction Techniques Using Ionic Liquids as Extraction Solvent

This work highlights the use of various types of ionic liquids (ILs) in microextraction techniques coupled to high-performance liquid chromatography (HPLC). In Chapter 2, magnetic ionic liquids (MILs) are used in headspace single-drop microextraction (HS-SDME) for the first time, where a rod magnet was employed to hold the MIL extraction phase. The use of magnetic force resulted in stable extraction phase during a long extraction time at high temperature conditions, overcoming the inherent disadvantage of traditional SDME method. In Chapter 3, polymeric ionic liquids (PILs) are employed as sorbent coatings for solid-phase microextraction (SPME) in high salinity sample matrix. Double-confined PIL coating was fabricated with monomer and crosslinker containing polymerizable cation and anion. The double-confined PIL fiber exhibited good extraction capabilities of ultraviolet filter compounds when high concentration of salt was present in the sample solution. The lifetime of the double-confined PIL fiber was much longer compared to that of commercially available PDMS/DVB fiber. The two methods highlighted in this thesis demonstrate the versatility of ionic liquids in sample preparation techniques and their future direction.