LC Enantioseparation of β-Lactam Stereoisomers through the Use of β-Cyclodextrin-Based Chiral Stationary Phases

Direct liquid chromatographic methods were developed to investigate the enantioseparation of 19 β-lactams on three cyclodextrin-bonded chiral stationary phases: permethyl-β-cyclodextrin, β-cyclodextrin and R,S-hydroxypropyl-β-cyclodextrin, prepared by a novel synthetic route. 17 of the 19 β-lactam stereoisomers were partially or baseline-separated on at least one of the tested chiral stationary phases. The influence of the structures of the β-lactams (the positions and types of the substituents, the size of the attached rings) on the enantiomer separation is discussed. The permethylated β-cyclodextrin selector proved to be the most effective one for the tested analytes.