Recent progress in the fundamental understanding of hydrophilic interaction chromatography (HILIC).

With the exponential growth in the application of the HILIC technique, there has been a significant progress in understanding the fundamental aspects of hydrophilic interaction chromatography. The experimental studies tend to be more extensive in terms of the number of stationary phases investigated and the number of probe compounds employed in comparison with the earlier studies; and more theoretical studies in quantitative structure retention relationship (QSRR) and molecular dynamics simulations have also been published and provide molecular-level insights into the retention mechanism. This review focuses on the recent progress in understanding the retention mechanism, retention models, selectivity, and the kinetic performance of HILIC. A better understanding of these fundamental aspects will undoubtedly facilitate more applications of this chromatographic technique in a wider range of fields.