ABSTRACT
Adopting a phase volume convention can mitigate the problems caused by the possible mixing of the adsorption and partition mechanism and by the selective preferential adsorption of mobile phase components in the stationary phase. Hydrophilic interaction liquid chromatography is becoming increasingly popular, as it often provides significant improvement in the retention and separation efficiency for the separation of polar and weakly ionic compounds. In an ideal chromatographic process, the equilibrium distribution of the sample compounds between the stationary and the mobile phases establish at any time in any part of the chromatographic bed. For rapid and efficient separations, the migration path of sample compounds to the active interaction sites should be as short as possible to minimize band-broadening by diffusion and to provide narrow peaks and high sample resolution. The retention factor and the diffusion coefficient of sample compounds depend on temperature, so that the solute migrates faster along the column at the center than near the walls.
