The roles of ionic liquids in sorptive microextraction techniques

The roles that ionic liquids (ILs) can play as extractants, intermediate solvents, mediators and desorption solvents in liquid-phase and solid-phase microextraction (SPME) provide the topic of this review. We emphasize the added value of using ILs in single-drop microextraction, hollow-fiber-based liquid-phase microextraction, dispersive liquid-liquid microextraction, and in-fiber and in-tube SPME, the most relevant being greater simplicity, greater selectivity, greater extractability and lower consumption of organic solvents. We also give systematic consideration to the requirements of detection as the next step. Further, we outline the unique properties of ILs that are exploited in each extraction procedure. The growing importance of microextraction techniques in sample preparation justifies this approach.