IntroductionHydrophilic interaction chromatography (HILIC) has been gain-ing rapid acceptance for the analysis of hydrophilic/polar/chargedsolutes since the early work of Alpert et al. [1] in 1990. Arguablyhowever, it was Martin and Synge [2] who first employed a HILIC-type separation, using a water-saturated bare silica column, albeitwith the water-immiscible solvent chloroform as the mobile phase,to separate polar amino acids. The retention mechanism was likelyto be similar in both studies. In HILIC, partitioning, hydrogen