CHIRAL-BONDED SILICA-GEL STATIONARY PHASES OBTAINED FROM CHIRAL SILANES FOR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - COMPARISON OF PERFORMANCE WITH THAT OF STATIONARY PHASES OBTAINED FROM GAMMA-AMINOPROPYLSILICA GEL

Several chiral triethoxysilanes, easily prepared from acidic or basic chiral compounds and aminopropyltriethoxysilane or isocyanatepropyltriethoxysilane were bonded onto silica gel. In the chiral stationary phases thus obtained, only silanol groups and the chiral selector can interact with solutes. To deactivate these silanol groups, an end-capping treatment with hexamethyldisilazane was applied. Unlike chlorotrimethylsilane, this reagent does not destroy the chemically bonded chiral silica gel. The performance of these stationary phases was evaluated and compared with that of bonded silica gel phases with the same chiral selector but fixed on gamma-aminopropylsilica gel. Chiral stationary phases obtained from chiral silanes and an end-capping treatment showed the best resolution and the shortest retention time for most of the compounds tested.