Investigating the effect of chromatographic conditions on retention of organic acids in hydrophilic interaction chromatography using a design of experiment

Small organic acids have shown significant retention on various stationary phases, such as amide, amino, aspartamide, silica and sulfobetaine phase commonly used in hydropkilic interaction chromatography (HILIC). This study investigated the effect of chromatographic conditions on the retention behavior of organic acids in HILIC using the tool of design of experiment (DOE). The results of the DOE study indicated that both the content of organic solvent (i.e., acetonitrile) and salt concentration in the mobile phase had significant effects on the retention of organic acids. Higher content of organic solvent in the mobile phase led to a significant increase in retention on all types of stationary phases. Increasing salt concentration also resulted in a moderate increase in retention; however, the effect of salt concentration varied with the type of stationary phase. The study also revealed that column temperature had less impact on retention than organic solvent content and salt concentration in HILIC.