Chiral separation of unmodified amino acids with non-aqueous capillary electrophoresis based on the ligand-exchange principle

A ligand exchange mechanism in non-aqueous capillary electrophoresis was em ployed for the separation of eight unmodified amino acids using chiral comp lexes of copper(II) with L-proline and L-isoleucine. The electrophoretic me dium consisted of 25 mM ammonium acetate and 1 M acetic acid in methanol. W e were able to completely separate the enantiomeric pairs of each of the in vestigated racemic amino acids. We also report the optimization of the sepa ration parameters, such as pH*, composition of the complex, and concentrati on of the complexing agents. (C) 2000 Elsevier Science B.V. All rights rese rved.