Affinity Separations in Magnetically Stabilized Fluidized Beds: Synthesis and Performance of Packing Materials

Abstract

A magnetically stabilized fluidized-bed separator designed to test the use of pellicular, ferromagnetic affinity chromatography packing materials has been developed. A wire wound solenoid was used to produce the magnetic field. The ferromagnetic packing material is comprised of a magnetite-containing, poly-urethane gel coated onto polystyrene beads. The gel contains free carboxyl groups. These were carbodiimide-coupled to soy-trypsin inhibitor and the material, used for trypsin purification. Narrow-band affinity chromatography was carried out in packed-bed, fluidized-bed and magnetically stabilized, fluidized-bed separators. Pressure drop, capacity, dilution, and peak asymmetry were evaluated for each type of separator. The three types provide comparable efficiency but the fluidized separators exhibit a much lower pressure drop. As might be expected, fluidized-bed separators perform well for affinity chromatography Oarge k') but poorly for size exclusion chromatography.