Enantioseparations using nonaqueous capillary electrochromatography on cellulose and amylose tris(3,5-dimethylphenyl carbamates) coated on silica gels of various pore and particle size

Enantioseparations of chiral compounds were studied in nonaqueous capillary electrochromatography (NAQ CEC) with cellulose and amylose tris(3,5-dimeth ylphenylcarbamates) (Chiralcel OD and Chiralpak AD, respectively) coated on the silica gels of various pore and particle size. Increasing intraparticl e perfusive transport with increasing pore size of silica favorably affecte d peak efficiency and resolution of enantiomers, although some decrease of separation factor was observed in the pore size range 60-200 Angstrom. Furt her improvement of peak efficiency was observed when the particle size of s ilica was reduced from 5 to 3 mum. The effects of a separation medium and t emperature are also reported and the data obtained in the same capillaries in CEC and capillary liquid chromatography (LC) mode are compared.