Enantioseparations by capillary electrophoresis using chiral glycosidic surfactants. II. Comparison of chiral cyclohexyl-alkyl-beta-D-maltoside surfactants

Three different glycosidic surfactants, namely cyclohexyl-butyl-beta-D-malt oside (CYMAL-4), cyclohexyl-pentyl-beta-D-maltoside (CYMAL-5), and cyclohex yl-hexyl-beta-D-maltoside (CYMAL-6), were compared in the enantioseparation of some dansyl amino acids and methylated tryptophans. The three CYMAL sur factants have the same chiral maltoside head group but differ in the length of the hydrophobic tail. Increasing the length of the hydrophobic tail see ms to shift the optimum surfactant concentration for maximum enantioresolut ion towards lower concentration values. In order to extend the range of opt imum surfactant concentration over which maximum enantioresolution can be a chieved, mixed CYMAL surfactant systems were introduced and evaluated. They consisted of mixing CYMAL-6 with either cyclohexyl-methyl-beta-D-maltoside (CYMAL-1) or cyclohexyl-ethyl-beta-D-maltoside (CYMAL-2).