Systematic evaluation of selected supercritical fluid chromatography diol- and diethylamine-based columns for application in hydrophilic interaction liquid chromatography
Abstract
Hydrophilic interaction liquid chromatography has become a useful method for separation of polar and hydrophilic analytes, i.e. compounds that are difficult to separate in reversed-phase chromatography. The retention mechanism in hydrophilic interaction liquid chromatography is rather complex.
Different types of interactions contribute to retention, depending on the properties of stationary phase, mobile phase and nature of analytes. Many columns for hydrophilic interaction liquid chromatography are available and the new stationary phases are still under development.
In our study systematic examination to describe two novel columns, intended for supercritical fluid chromatography, as potential stationary phases for hydrophilic interaction liquid chromatography was performed. The supercritical fluid chromatography columns contained polar diethylamine ligand and diol ligand bonded to ethylene bridged hybrid particles.
The retentivity and selectivity of the stationary phases were evaluated using a variety of test compounds. The impacts of acetonitrile content, buffer pH and concentration on the retention were investigated.
Distinct mixed-mode behavior of the diethylamine column was observed; significant contribution of anion-exchange interaction to retention was confirmed. The DIOL phase has neutral character and retained analytes predominantly by hydrophilic interaction liquid chromatography mechanism.