Chiral Ionic Liquid Based Biphasic Systems in Enantioseparations

Aqueous two-phase separation (ATPS) is a powerful, greener tool for the partitioning-based extraction and concentration of compounds in a mixture. ATPS is characterized by the separation of the biphasic layers upon the addition of the aqueous salt solution to aqueous ionic liquids. The aqueous biphasic system using chiral ionic liquids (CILs) has been studied for the resolution of the chiral molecules and their enantioseparation. Thus, in this chapter, abrief introduction to the ATPS formation thermodynamics for the polymer-polymer, polymer-salt, and salt-salt type ionic liquid isgiven. Apart from this, the effect of the salt, pH, and temperature on the physicochemical behavior of aqueous biphasic systems is discussed. The chiral ionic liquid-based ATPS is further categorized as tetrabutylammonium, choline, imidazolium, tropine, and quinine-based ionic liquids for enantioseparation. The study includes the effect of salts, cation of IL, anion of IL, temperature, pH, and Cu2+ ions. The chiral resolution of molecules and biomolecules is studied using these ionic liquids for amino acids and proteins.