Liquid chromatographic separation of the enantiomers of beta-amino acids on a ligand exchange chiral stationary phase.

A liquid chromatographic ligand exchange chiral stationary phase (CSP) derived from (S)-leucinol was applied in the separation of the enantiomers of 12 beta-amino acids. The resolution was quite successful especially for the enantiomers of beta-amino acids containing aromatic functional group in the side chain. The chromatographic resolution behaviors were dependent on the organic modifier and Cu(II) concentration in aqueous mobile phase and the column temperature.

New ligand exchange chiral stationary phase for the liquid chromatographic resolution of alpha- and beta-amino acids.

A new ligand exchange chiral stationary phase (CSP) has been developed by covalently bonding (R)-N,N-carboxymethyl undecyl phenylglycinol mono-sodium salt onto silica gel and applied in the resolution of alpha- and beta-amino acids. In the resolution of alpha-amino acids, the new CSP was better insome cases than the old one, which was previously developed by covalently bonding (S)-N,N-carboxymethyl undecyl leucinol mono-sodium salt onto silica gel, but worse in some other cases than the old one in terms of the separation factors (alpha). However, the new CSP wasalways much better than the old one in terms of the resolution factors (Rs). In the resolution of beta-amino acids, the new CSP was always much better than the old one in terms of both the separation and resolution factors. In an effort to characterize the new CSP, the chromatographic behaviors for the resolution of selected alpha- and beta-amino acids were investigated with the variation of the content of organic modifier and Cu(II) concentration in aqueous mobile phase and the column temperature.