Determination of selectivity of HPLC systems by correspondence factor analysis

Correspondence factor analysis (CFA) was employed to study the selectivity of 14 HPLC systems. The tested LC systems were classified as reversed-phase (RP), ion-exchange (IE) and hydrophilic interaction chromatography (HILIC) modes. It was found that the retentions of the hydrophilic solutes on HILIC column were significantly influenced by the second-order effects besides their hydrophilic properties. Organic modifiers and residue silanol groups on silica surface both participated in retention. Hypersil™ amino column performed separation in the HILIC mode at appropriate conditions, and its retention mechanism was more similar to that of HILIC silica column than that of HILIC column coating poly(aspartamide) groups.