Chiral separation of beta-methyl-amino acids by ligand exchange using capillary electrophoresis and HPLC

This paper deals with the chiral separation of optical isomers of beta-methyl-amino acids by CE and HPLC using the principle of ligand-exchange. Capillary zone electrophoresis was carried out using Cu(II) complexes of L-4-hydroxyproline (L-4-Hypro), N-(2-hydroxypropyl)-L-4-hydroxyproline (HP-L-4-Hypro) and N-(2-hydroxyoctyl)-L-4-hydroxyproline (HO-L-4-Hypro) as chiral selectors, added to the electrolyte. The HPLC separations were performed on a chiral stationary ligand-exchange chromatography phase containing L-4-Hypro chemically bonded to silica gel. With both techniques nearly all compounds investigated are baseline resolved using different background electrolytes and mobile phases, respectively.