Hydrophilic interaction chromatography on silica column: retention mechanism and its influential factors

Hydrophilic interaction chromatography (HILIC) is a valuable alternative to reversed phase liquid chromatography (RPLC) for the analysis of highly polar and hydrophilic compounds, in which the separation mechanism is quite different from RPLC and the separation selectivity is complementary to RPLC. This separation mode can be characterized as normal phase liquid chromatography (NPLC) on polar columns in aqueous-organic mobile phases rich in organic solvents (usually acetonitrile). Silica has been the earliest developed and most widely used HILIC stationary phase. This review deals with the recent advances in the development of the retention mechanism on silica column with special attention to the effects of stationary phase, mobile phase composition and temperature on separation in HILIC mode. Moreover, the developing trends and applications of this HILIC mode are presented.