Abstract
A comprehensive retention and selectivity characterization of five hydrophilic interaction chromatography (HILIC) stationary phases was performed with seven polar pesticides (acephate, methamidophos, asulam, mecoprop, triclopyr, dalapon and amitrole), in order to study the effect of surface chemistry and mobile phase composition on chromatographic behavior and ESI-MS response. Selectivity differences were compared for all columns operated in neutral condition. Additionally,the influence of mobile phase condition on retention behavior was studied for each column. In our results, an increase of the percentage of organic solvent in the mobile phase led to an increase of the retention factor and the number of theoretical plate for all analytes and all columns, whereas the significant differences in the effect of salt concentration were observed for different stationary phases. In addition, moderate differences in selectivity were observed on the same column operated at different pH, especially in acidic compounds. In general, higher column temperature led to weaker retention and, however, the decreasing rate of retention time depended on the characteristics of stationary phase and target compound. In some case, the retention increased with the temperature on HILIC column. The data from this study can be used to establish guidelines for rapid HILIC method development of polar compounds.
