Enantiomeric separation by capillary electrochromatography using monolithic capillaries with sol-gel-glued cyclodextrin-modified silica particles

By an on-column sol-gel process, a chiral monolithic stationary phase was prepared by the fusion of permethyl-beta-cyclodextrin-silica (Chira-Dex-silica) particles and by linking them to the internal capillary wall. The resulting monolith is stable toward voltage (30 kv) and pressure (300 bar) and possesses a high efficiency (up to 100 000 theoretical plates per meter). Efficient enantiomeric separation of various chiral compounds by pressure-supported capillary electrochromatography (CEC) was achieved. When comparing this method to capillary liquid chromatography (LC) employing the same column in an unified equipment, CEC shows a twofold higher column efficiency at comparable elution times and hence better resolution factors.