Abstract
Packed capillary and microbore column supercritical fluid chromatography (SFC) using a newly developed, highly cross‐linked ethylvinylbenzene and divinylbenzene (EVB–DVB) polymer as the packing material is presented. The EVB–DVB polymer stationary phase has been developed specifically for microbore packed column SFC applications. Compared to silica‐based packing materials, the EVB–DVB polymer is much more inert and free of active adsorption sites, has very good temperature and pressure stabilities, and is compatible with common organic solvents and aqueous samples (pH 0 to 14). The capillary and microbore columns packed with the EVB–DVB polymer have been used successfully to separate a number of polar and nonpolar compounds such as alkanes, free fatty acids, aromatic amines, and cyclic amines using pure supercritical CO~2~ as the mobile phase. The experimental results indicate that the retention mechanism of polar and nonpolar compounds on the EVB–DVB polymer stationary phase is governed by the surface adsorption–desorption that is an apolar–apolar interaction; the retention mechanism also is significantly influenced by the π–π surface interaction in π‐electron‐rich solutes because of the high density of π‐electrons associated with the aromatic components of the stationary phase. Some important practical aspects and comparisons between capillary and microbore packed columns in SFC applications are also discussed.