MOLDED RIGID POLYMER MONOLITHS AS SEPARATION MEDIA FOR CAPILLARY ELECTROCHROMATOGRAPHY

Rigid, monolithic capillary columns for reversed-phase electrochromato graphy have been prepared within the confines of untreated fused-silic a capillaries in a single step by a simple copolymerization of ethylen e dimethacrylate, butyl methacrylate, and 2-acrylamido-2-methyl-1-prop anesulfonic acid in the presence of a porogenic soh ent. The compositi on of the specifically designed ternary porogenic solvent allows fine control of the porous properties of the monolithic material over a bro ad range. While the electroosmotic now through these capillary columns increases with both increasing pore size of the monolith and content of charged functionalities, better chromatographic properties have bee n observed for monoliths with larger surface area and hydrophobicity. Using this technique, monolithic capillary columns with an efficiency higher than 120 000 plates/m have been easily obtained.