Planar Chromatography Enantioseparations on Noncommercial CCSPs
Chiral-coated stationary phases (CCSPs) consist of specific chiral selectors permanently adsorbed onto the surface of achiral thin layer chromatography materials without covalently modifying their chemical characteristics. A large number of CCSPs were prepared in laboratory by several researchers owing to the ease of the impregnation procedures and the variety of chiral selectors used as impregnating agents. Applications of chiral ligand exchange chromatography in planar chromatography are concerned with the enantiomeric separation of several polar organic compounds, particularly α-amino acids and their derivatives, α-hydroxy acids, and peptides. The chapter discusses the use of silica gel layers coated with acid or basic chiral selectors and the amino acids employed as chiral impregnating agents. The use of amino acids as chiral agents involved further possibilities of enantiomeric resolution owing to the simultaneous presence of acidic and basic groups. Such compounds can be classified in relation to the number of acidic and basic groups present in the molecule.