Preparation of Perphenylcarbamoylated β-Cyclodextrin-silica Hybrid Monolithic Column with "One-Pot" Approach for Enantioseparation by Capillary Liquid Chromatography

Perphenylcarbamoylated beta-cycloclextrin-silica (Ph-beta-CD-silica) hybrid monolithic columns for enantioseparation in capillary liquid chromatography (cLC) have been prepared by a "one-pot" approach via the polycondensation of alkoxysilanes and in situ copolymerization of mono (6(A)-N-allylamino-6(A)-deoxy)-Ph-beta-CD and vinyl group on the precondensed siloxanes. The morphologies of the Ph-beta-CD-silica hybrid monolithic columns were characterized by optical microscopy and scanning electron microscopy (SEM), showing the uniform monolithic matrixes tightly bonded onto the capillary wall. The content of Ph-beta-CD incorporated in monolithic matrix by the "one-pot" approach was ca. 2.9 times higher than that by postmodification method. The permeability of the Ph-beta-CD-silica chiral hybrid monolithic column was 3.63 x 10(-14) m(2), and the minimum plate height was 12 pm corresponding to 83 300 theoretical plates/meter. Enantioseparations of 13 racemates were achieved by the Ph-beta-CD-silica hybrid monolithic column. In this work, since the prepolymerization system mainly consisted of organic solvent (methanol (MeOH), N, N-dimethylformamide (DMF)), the limitation and difficulty of the use of water insoluble organic monomers in the previously reported "one-pot" method was circumvented. Therefore, various beta-CD derivatives as well as other hydrophobic monomers could thus be used to prepare organic silica hybrid monolithic columns with the "one-pot" process.