Capillary electrochromatography column behavior of butyl and lauryl acrylate porous polymer monoliths

A variety of porous polymer monoliths (PPMs) have been synthesized using the ‘conduct-as-cast’ format. The resulting polymers have been evaluated for use as separation media in capillary electrochromatography (CEC). The results have shown that substituting a small percentage of the standard polymer formulation with a more hydrophobic monomer produced columns with expected increases in retention for a neutral analyte series. However, substituting larger percentages of a more hydrophobic monomer resulted in columns that exhibited less retention. The unexpected behavior of these hydrophobic columns has been attributed to the non-uniform polymerization of the more hydrophobic monoliths. Van Deemter plots of polyaromatic hydrocarbons have been examined to further analyze the unexpected behavior of these columns. Hmin values ranged from 8.7 to 9.1 μm for the columns evaluated. The effect of the percentage of organic modifier in the mobile phase on the separation has also been studied. The retention window decreases when altering the ACN concentration in the mobile phase from 50% to 80% (v/v).