Ionic liquids in the microextraction techniques: The influence of ILs structure and properties

Ionic liquids (ILs) are composed entirely of ions thus they possess unique properties, including negligible volatility, a liquid state in a broad range of temperatures and ability to change them depending on the chosen type of anion and cation, which make ILs unique and useful for many applications in sample preparation techniques. A deeper understanding of the nature of ILs and the impact of their structure on their parameters is the key to the success of conscious use of them as potential sorption media for a given purpose. This review describes the key physical and chemical properties of ILs in the context of their importance in sample preparation techniques. The review also presents selected combinations of ILs with solid-phase microextraction, SPME; single drop microextraction, SDME; dispersive liquid-liquid microextraction, DLLME, in terms of the role of ILs properties in a given technique.