Combined chiral crown ether and beta-cyclodextrin for the separation of o-, m-, and p-fluoro-D,L-phenylalanine by capillary gel electrophoresis

A combination of (beta-CD) with a chiral crown ether, 18-crown-6-tetracarboxylic acid (18C6TA), has been used for the chiral capillary gel electrophoretic (CGE) separation of the six enantiomers and positional isomers in a mixture of o-, m-, and p-fluoro-D,L-phenylalanine; the isomers were successfully resolved in 0.3 % agarose -2 x 10(-2) mol L(-1) 18C6TA -2 x 10(-2) mol L(-1) beta-CD. The method has also been successfully extended to the separation of the enantiomers of 13 other amino acid or primary amine substrates. The role of the chiral crown ether was studied. The effects of the concentrations of 18C6TA, beta-CD and agarose, and of pH and applied field strength on the migration time and separation factors of the analytes are reported.