title: The retention behaviour of amino acids in hydrophilic interaction liquid chromatography on zwitterionic stationary phases.
abstract: The retention behaviour of amino acids was studied in hydrophilic LC on zwitterionic stationary phases. Evaluation of the influences of acetonitrile/water content, ammonium acetate (NH4Ac) concentration and mobile phase pH values was performed. Fourteen amino acids were tested and they were all retained to varying extents, with poorer retention in high water content eluents. The linear relationship between the logarithm of retention factor and log(water content) indicated that adsorption dominated or at least was partly involved in the separation mechanism. Electrostatic and hydrophilic interactions also contributed to the retention of these amino acids under different separation conditions with various mobile phase pH values and NH4Ac concentrations. Thus, the overall retention mechanism could be explained as a combination of adsorption, electrostatic and hydrophilic interactions. The magnitude and contribution of each mechanism is dependent on the nature of the analyte and the separation conditions applied.
authors: Australian Centre for Research on Separation Science, School of Chemistry, Monash University, Melbourne, Australia.
authors: Ze-Ying
authors: ZY
authors: Wu
authors: Junfeng
authors: J
authors: Liu
authors: Hong
authors: H
authors: Shi
authors: Philip J
authors: PJ
authors: Marriott
mesh_terms: D000327:Adsorption; D000596:Amino Acids / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000295:instrumentation* / Q000379:methods; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions
chemical_list: D000596:Amino Acids
keywords: Amino acids; Hydrophilic interaction LC; Retention behaviour; Zwitterionic