Enantioseparation by Capillary Electrophoresis Using Cyclodextrins in an Amino Acid-Based Ionic Liquid Running Buffer

For enantioseparations of chiral drugs in capillary electrophoresis, chiral ionic liquids (CIL) can be employed instead of traditional running buffer containing a chiral selector. CILs can be applied solely or in addition to the often used cyclodextrin derivatives. Here the separation of phenethylamines, especially of ephedrine, is described using tetrabutylammonium L-argininate (125 mM) in phosphate buffer (75 mM, pH 1.5) in addition to β-cyclodextrin (30 mM). Using this dual-chiral running buffer system ephedrine, pseudoephedrine and methylephedrine, but not norephedrine, could be easily resolved.