Abstract: Hydrophilic interaction chromatography (HILIC) is popular in the analysis of hydrophilic solutes in recent years. As a unique liquid chromatographic (LC) separation mode, it has not only been successfully utilized for the separation of target compounds from complex matrixes, but also been hyphenated with other separation modes, such as reversed-phase LC (RPLC), ion-exchange chromatography, and various HILIC, to increase the resolution and peak capacity for “entire-component” analysis of complex samples. Here we briefly review the origin and concept of HILIC, its retention behavior, and the frequently used stationary phases. After discussing the selectivity orthogonality between HILIC and RPLC, several application areas of HILIC are introduced, including HILIC tandem mass spectrometry (HILIC-MSn), on-line HILIC pretreatment, comprehensive two-dimensional HILIC-MSn and on-line hyphenation of HILIC and RPLC. With abundant references, HILIC has been proved to be a powerful analytical tool for hydrophilic and polar complexes.

Key words: column-switching, hyphenated techniques, multi-dimensional separation , hydrophilic interaction chromatography (HILIC)