State-of-the-art extraction and separation of enantiomers through the application of alternative solvents

Enantiomeric separation is an increasing research area, as well as the application of alternative solvents replacing classic volatile, flammable and toxic organic solvents. Among these novel solvents, chiral ionic liquids (CILs) have been widely used in sample preparation (extraction), gas chromatography, liquid chromatography, capillary electrophoresis and other techniques involved in enantioseparation. Likewise, surfactants and deep eutectic solvents have gained increasing attention in the last years because they are valid alternatives to CILs with a lower cost and/or diminished environmental impact. This review provides a comprehensive overview of the latest developments using these modern solvents applied to enantioseparations, focusing mainly on the applications of CILs. Furthermore, separation and preconcentration of chiral analytes in different matrices are also reviewed in this article. Articles published since 2017 to present were reviewed in this work. Critical discussion on their analytical application and future challenges related to their use are also included in this review.