7. Extraction of Alcohols, Phenols, and Aromatic Compounds with ABS

Ionic-liquid-based aqueous biphasic systems (IL-based ABS) combine the advantages of both ionic liquids (ILs) and aqueous biphasic systems (ABS) in extraction approaches. Most ILs are liquid solvents exclusively composed of ions, characterized for low to negligible vapor pressures at ambient conditions, extraordinary chemical and thermal stabilities, and impressive solvation abilities for polar to nonpolar compounds, among many other properties. ABS permit the development of extraction methods without the need of using toxic and volatile organic solvents, while both immiscible phases involved in the extraction procedure are aqueous rich. Thus, the combination of hydrophilic ILs with ABS has implied numerous effective applications for different target compounds. In this chapter, attention is focused on applications of IL-based ABS for the extraction of alcohols, phenols, aromatic dyes, and other aromatic compounds. The discussion is centered on the nature of the IL-based ABS, their characterization, and the performance of the extraction procedure, among other features.