title: Chromatographic characterization of hydrophilic interaction liquid chromatography stationary phases: hydrophilicity, charge effects, structural selectivity, and separation efficiency.
abstract: Fourteen commercially available particle-packed columns and a monolithic column for hydrophilic interaction liquid chromatography (HILIC) were characterized in terms of the degree of hydrophilicity, the selectivity for hydrophilic-hydrophobic substituents, the selectivity for the regio and configurational differences in hydrophilic substituents, the selectivity for molecular shapes, the evaluation of electrostatic interactions, and the evaluation of the acidic-basic nature of the stationary phases using nucleoside derivatives, phenyl glucoside derivatives, xanthine derivatives, sodium p-toluenesulfonate, and trimethylphenylammonium chloride as a set of samples. Principal component analysis based on the data of retention factors could separate three clusters of the HILIC phases. The column efficiency and the peak asymmetry factors were also discussed. These data on the selectivity for partial structural differences were summarized as radar-shaped diagrams. This method of column characterization is helpful to classify HILIC stationary phases on the basis of their chromatographic properties, and to choose better columns for targets to be separated. Judging from the retention factor for uridine, these HILIC columns could be separated into two groups: strongly retentive and weakly retentive stationary phases. Among the strongly retentive stationary phases, zwitterionic and amide functionalities were found to be the most selective on the basis of partial structural differences. The hydroxyethyl-type stationary phase showed the highest retention factor, but with low separation efficiency. Weakly retentive stationary phases generally showed lower selectivity for partial structural differences.
authors.affiliation: Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
authors.forename: Yuusuke
authors.initials: Y
authors.lastname: Kawachi
authors.forename: Tohru
authors.initials: T
authors.lastname: Ikegami
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Takubo
authors.forename: Yuka
authors.initials: Y
authors.lastname: Ikegami
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Nobuo
authors.initials: N
authors.lastname: Tanaka
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007474:Ion Exchange; D007477:Ions / Q000737:chemistry; D008968:Molecular Conformation; D009930:Organic Chemicals / Q000737:chemistry; D025341:Principal Component Analysis; D055672:Static Electricity
chemical_list: D000097:Acetonitriles; D007477:Ions; D009930:Organic Chemicals; C032159:acetonitrile