Novel instrumental methods for supercritical fluid chromatography

Abstract

This thesis explores five main research themes all aimed at improving the capabilities of supercritical fluid chromatography (SFC) using both packed (pSFC) or capillary (cSFC) columns. In the first study, the addition of a high water content into a 2-propanol modifier was explored in pSFC. With this new modifier, very polar compounds (e.g. ionic salts, polyhydroxycarboxylic acids, and amino acids) can be readily eluted from non-polar and polar columns. In a second study, both an ultrasonic bath and probe were each employed in SFC separations but did not demonstrate any great effect. Next, in studying the restoration of column efficiency loss caused by pressure drops, a small resistively heated coil at the colunm inlet was found to improve the peak shape significantly. In the last two studies, this heating coil was further used to control column pressure and flow rate independently in both cSFC and pSFC.