Chromatographic evaluation of large-pore and non-porous polymeric reversed phases

The polymeric reversed-phase packing material, PRP-1, a macroporous copolymer of styrene and divinylbenzene has been used for the liquid chromatographic analysis of proteins, peptides, oligonucleotides, pharmaceuticals and other biologically active materials. The PRP-1 phase has an average pore diameter of 75 A which may limit its applicability to smaller molecules. Hence a complementary series of larger pore poly(styrene-divinylbenzene) packing materials has been prepared. Chromatographic evaluation of 100-, 200- and 300-A polymeric stationary phases showed identical small molecule selectivity through the series and similar sample load capacities. The 300-A material showed the best resolution of protein samples during gradient elution. Its performance is compared to that of a non-porous PRP whose pore diameter may be considered infinite. Ghosting, recovery and column efficiency were also evaluated. The chief benefit of the PRP packing is its hydrolytic stability from pH 1 to 13. Hydrolytic removal of protein contaminants from analytical PRP columns and packings was demonstrated.