Ionic liquid as porogen in the preparation of a polymer-based monolith for the separation of protein by high performance liquid chromatography

A novel polymer-based monolith for high performance liquid chromatography was fabricated via atom transfer radical polymerization without the expensive complexing ligand, in which methyl methacrylate was used as the monomer, vinyl ester resin as a cross-linker, 1-butyl-3-methylimidazolium chloride/dodecanol as the porogen, carbon tetrachloride as the initiator and ferrous chloride as the catalytic agent. The morphology of the monolith was studied using scanning electronic microscopy. The chemical groups of the monolith were assayed using the infrared spectroscopy method. The pore size distribution was determined using a mercury porosimeter and nitrogen absorption-desorption isotherms. The monolith was used to separate lysozyme from chicken egg white in a short time with good resolution and reproducibility. The effects of pH and buffer concentration on elution have been investigated. In addition, the monolith was used to separate a mixture of proteins (bovine serum albumin, papain and lysozyme) and aromatic compounds with good resolution.