Enantioselective determination of (R)- and (S)-sotalol in human plasma by on-line coupling of a restricted-access material precolumn to a cellobiohydrolase I-based chiral stationary phase.

A liquid chromatographic column-switching method for the enantioselective determination of (RS)-sotalol in plasma was developed and validated. The method is based on the on-line coupling of a precolumn filled with the restricted access material LiChrospher ADS to a cellobiohydrolase I-based chiral stationary phase (CSP). The plasma samples were injected onto the precolumn using a mobile phase containing 1% methanol in 10 mM phosphate buffer at pH 7.

Comparison of three chiral stationary phases with respect to their enantio- and diastereoselectivity for cyclic beta-substituted alpha-amino acids.

Three chiral stationary phases were examined for the enantio- and diastereoseparation of cycloaliphatic beta-substituted alpha-quaternary alpha-amino acids. Resolution of diastereomeric analytes is feasible with a chiral crown ether based column, whereas the separation of enantiomers, except for one pair of amino acids, could not be achieved. The two chiral stationary phases with the glycopeptide antibiotic teicoplanin and with the copper(II)-D-penicillamine complex, respectively, are, however, both very potent in the separation of the enantiomeric, as well as of the diastereomeric amino acids.