Effect of porous structure of macroporous polymer supports on resolution in high-performance membrane chromatography of proteins.

The effect of porous structures of 2-mm thick diethylamine functionalized monolithic polymethacrylate discs on their chromatographic behavior in ion-exchange mode has been studied. Discs with small pores did not perform well because they exhibited high back pressure and substantial peak broadening. Discs characterized with pores larger than 1,000 nm did not provide good separations either because the time required for some protein molecules to traverse the length across the pore to reach the wall for adsorption/desorption process that is essential for the separation may be longer than their residence time within the matrix. Optimum pore size is centered at about 700 nm. Excellent separations have been achieved with these discs even at very steep gradients and high flow-rates which allow to shorten the separation times substantially.