Synthesis of Polar Polymeric Monoliths and Their Evaluation in Normal Phase Capillary Electrochromatography

Abstract

This research has focused on the development of polar polymeric monolithic stationary phases for capillary electrochromatography (CEC). This involved novel monolithic stationary phases with polar function groups. They were prepared by the in situ copolymerization of ethylene glycol dimethacrylate and 2-acrylamido-2-methyl-1-propanesulfonic acid with either 2-cyanoethyl acrylate or 1-vinyl-2-pyrrolidinone (VP) in different porogenic solvents to produce columns with different functional groups. To further enlarge the scope of applications of monoliths, we modified the surface of monoliths based on the copolymerization of glycidyl methacrylate and ethylene dimethacrylate with 1-H-imidzaole-4,5-dicarbonitrile or diethylenetriamine to increase the polarity of the column. Organic polymeric monolithic stationary phases thus developed proved to be useful for the normal phase CEC separations of neutral and charged solutes. The VP monolithic columns exhibited normal-phase retention mechanism toward neutral solutes (e.g. oligosaccharides) and a mixed mode retention behavior with charged solutes, e.g., phenols and chlorophenols. The monolithic columns with surface-bound diethylenetriamine were successfully used to separate dipeptides.