Selectivity tuning and molecular modeling of new generation packings for RP HPLC

Retention mechanism, selectivity and physicochemical properties together with theoretical surface simulation experiments of laboratory-synthesized packing materials for high performance liquid chromatography (HPLC) containing cholesterol molecules immobilized on the high quality silica gel were studied. The chromatographic behavior of the three cholesterol-based columns (SG-CHOL, SG-MIX CHOL/AP and SG-10-CHOL) was examined with special regard to retention and selectivity and compared to reference materials: a typical octadecylsilica column (SG-C18) and an alkylamide bonded phase (SG-AP). Temperature investigations (DSC) and molecular modeling simulations didn't bring an expected confirmation of liquid crystalline properties of materials studied. The observed phase transition was attributed to conformation change within the amide bonding.