Hydrophilic interaction chromatograph

High-Performance Hydrophilic Interaction Chromatographic Separation of... 

Hydrophilic interaction chromatography (HILIQ has been practiced for a long time, but its name has only recendy been coined by Alpert (1). Previously, the techniques of HILIC were lumped together with other unrelated chromatographic techniques, often in ignorance of the actual separation mechanism. This has led to an unfortunate confusion in the literature. 

Wikberg, E., Sparrman, T., Viklund, C., Jonsson, T., and Irgum, K. 2011. A nuclear magnetic resonance study of the state of water in neat sihca and zwitterionic stationary phases and its influence on the chromatographic retention characteristics in hydrophilic interaction high-performance liquid chromatography. J. Chromatogr. A 1218 6630-6638. 

Hydrophilic interaction chromatography (HILIC) uses polar stationary phases. Thus, polar analytes can be separated with high efficiency. It is sometimes regarded as a type of partition chromatography - one of the early chromatographic modes. 

Hydrophilic Interaction LC-MS-Based Approaches Hydrophilic interaction LC (HILIC) is a variant of normal-phase LC. HILIC uses hydrophilic stationary phases, but employs reversed-phase type eluents. Any polar chromatographic surface can be used for HILIC separations, even nonpolar bonded silicas. A typical mobile phase for HILIC includes acetonitrile with a small amount of water. However, any aprotic solvent miscible with water (e.g., tetrahydrofunan or dioxane) can be used. Alcohols can also be used with a higher concentration. Ionic additives, such as ammonium acetate and ammonium formate, are usually used to serve as the modifiers for controlling the pH and ion strength of the mobile phase. 

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