IMPROVEMENT OF THE ENANTIORECOGNITION ABILITY OF TYROSINE-DERIVED CHIRAL STATIONARY PHASES - DIRECT RESOLUTION OF 1,2-AMINO-ALCOHOLS (BETA-BLOCKERS)

A novel chiral stationary phase (CSP) derived from tyrosine is evaluated with regard to the first generation commercially available (S)-ChyRoSine-A CSP, under normal-phase or reversed-phase liquid chromatographic (NPLC or RPLC) and subcritical fluid chromatographic (SubFC) conditions. The complete scope of application of these CSPs is reviewed. The novel CSP, which bears a bulkier functional group, displays a higher enantiorecognition ability than previously described (S)-ChyRoSine-A toward about 15 families of racemates, whatever the mobile phase conditions. The direct enantiomeric separation of 1,2-amino-alcohols (beta-blockers) is carried out on both CSPs. Facile separations are achieved within short analysis times using SubFC mode, whereas very poor separations are obtained using NPLC mode. These results disagree with previous theories (interchangeability between NPLC and SubFC modes).