PREPARATION AND EVALUATION OF A BIMODAL SIZE-EXCLUSION CHROMATOGRAPHY COLUMN CONTAINING A MIXTURE OF 2 SILICAS OF DIFFERENT PORE DIAMETER

Size-exclusion results from four different pore-sized silicas were used to select two of these silicas for use in a bimodal size-exclusion column. A mixture of 80- and 500-angstrom pore-sized silicas provided an exclusion curve of elution volume versus log molecular weight with a linear range from 5 x 10(2) to 2 x 10(6) MW. The exclusion properties were retained when a reversed-phase packing was prepared by using the mixed pore-sized silica. Column efficiency was found to be virtually independent of pore size.