[Preparation of multi-hydroxyl molecular-bonded stationary phase for hydrophilic interaction chromatography and its...

The surface of silica was modified by delta-gluconolactone, a multi-hydroxyl molecule, to prepare a new stationary phase for hydrophilic interaction chromatography (HILIC) of strongly polar compounds from traditional Chinese medicine. The separation properties and separation mechanisms of the stationary phase to six polar components were investigated by changing kinds of organic solvent (ethanol, acetonitrile and tetrahydrofuran) and concentration, salt concentration and column temperature. The retention times of the solutes decrease with increasing the concentration of water in mobile phase from 0 to 40% (v/v), indicating a typical HILIC mode for the separation of the solutes, whilst the curves of the retention times of the six solutes exhibit "U" shape with the change in the concentration of the water from 0 to 100% (v/v), indicating a mixed-mode of hydrophilic interaction and reversed-phase chromatography working on the separation of the solutes. The results of the salt concentration and pH affected the retention time show that there were weak electric interactions between the solutes and the prepared stationary phase. The fact that the strongly polar solutes and Danshen injections could be separated well indicated that the prepared stationary phase has a potential application in the separation of strongly polar components in traditional Chinese medicine and other strongly polar compounds.