Chiral-coated stationary phases enantioseparations

Cass et al. [66] used a polysaccharide-based column on multimodal elution for the separation of the enantiomers of omeprazole in human plasma. Amylose tris (3,5-dimethylphenylcarbamate) coated onto APS-Hypersil (5 /im particle size and 120 A pore size) was used under normal, reversed-phase, and polar-organic conditions for the enantioseparation of six racemates of different classes. The chiral stationary phase was not altered when going from one mobile phase to another. All compounds were enantioresolved within the elution modes with excellent selectivity factor. The separation of the enantiomers of omeprazole in human plasma in the polar-organic mode of elution is described. 

Although packed columns have been used in earlier studies, capillary columns containing wall-coated or immobilized chiral selectors are more widely used at present. The chiral selector may be of different nature, such as amino acid derivatives, chiral metal complexes, etc. [90], At present, cyclodextrins (CD) and their derivatives dominate as chiral stationary phases (CSP) in GC enantioseparations [90, 91], CD-based CSPs for GC are thermally stable, widely applicable, and easy to use. 

Lomsadze K, Jibuti G, Farkas T, Chankvetadze B. Comparative high-performance liquid chromatography enantioseparations using polysaccharide based chiral stationary phases prepared by coating of totally porous and core-shell silica particles. J Chromatogr A 2012 1234 50-55. 

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