Conduct-as-Cast Polymer Monoliths as Separation Media for Capillary Electrochromatography

We have developed porous polymer monoliths (PPMs) that are versatile and robust reversed-phase chromatography media. The PPMs are cast-to-shape, UV-cured polymers that form uniform packings within pretreated glass capillaries and fused-silica chips. No applied pressure is ever needed to flush the PPMs since they support electroosmotic flow as cast. Such characteristics make the PPMs useful for chip-based devices. Our results show efficiencies greater than or equal to 150 000 plates/m for both capillary and chip-based separations of polycyclic aromatic hydrocarbons. By changing the monomers, the hydrophobicity of the polymers, and the direction of the electroosmotic flow can be altered without degrading chromatographic performance. We describe here the development of these acrylate-based materials along with both physical and chromatographic characterization.