AMINO ACIDS BASED CHIRAL IONIC LIQUIDS FOR ENANTIOMER SEPARATION BY CAPILLARY ELECTROPHORESIS

Room temperature chiral ionic liquids (CILs) are a relatively new class of ionic compounds; they act as efficient chiral selectors and modifiers of the capacity of enantiodiscrimination in electrophoretic or chromatographic separations. The aim of this study was to synthesize and characterize according to literature new ionic liquids, tetrabutylammonium and tetramethylammonium amino acid salts (chiral anions: 1-leucine, 1-proline, 1-histidine) and to investigate their effect on chiral separations of some pharmaceutical active ingredients racemates (ondansetron, mianserin, ofloxacin) using capillary electrophoresis. CILs alone were not able to discriminate the isomers of ondansetron, ofloxacin and mianserin, but the results proved that the enantioselectivity of hydroxypropyl-p-cyclodextrin (HP(3CD) increased when CILs were added in the background electrolyte (BGE) containing cyclodextrin. Several parameters (pH, CIL and cyclodextrin concentration, applied voltage and temperature) were studied and their effect on enantioselectivity was highlighted. The obtained results proved the synergistic action of CIL and cyclodextrins in the chiral recognition and enantioseparation process.