Porous Polymer Monoliths for Capillary Electrochromatography Michelle M. Bushey. Department of Chemistry, Trinity University, One Trinity Place, San Antonio, TX 78212-7200 We have investigated a variety of porous polymer monoliths in the butyl and lauryl acrylate family for use in capillary electrochromatography. Our test analytes include a homologous series of toluene through 1-phenyl nonane and selected polycyclic aromatic hydrocarbons. In our system, the polymer monolith is cast in situ in fused silica capillaries. Heat initiates the polymerization and the resulting monoliths are conductive as cast. These materials behave quite differently from traditional chromatographic packing material and they hold great promise as stationary phases. It is important to understand their behavior and performance limits and features. Our investigations have included studies on the reproducibility of these columns and their longevity. We have compared a variety of columns with each other in terms of performance as measured by van Deemter curves, and retention factors. Minimum plate heights for many of our columns are in the vicinity of 8 micrometers. The enthalpy of partitioning has been measured on several columns and the obstruction factor has been determined. Butyl acrylate polymer in 75 mm capillary