SUPERFICIALLY POROUS SILICA MICROSPHERES FOR THE FAST HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF MACROMOLECULES

New superficially porous "Poroshell" particles have been synthesized and tested for HPLC separations of macromolecules. Spray-drying techniques were used to prepare silica microspheres that typically have a 5-mu-m solid core and a approximately 1-mu-m-thick outer shell with 300-angstrom pores. Compared to conventional totally porous particles of the same size, Poroshell particles show improved mass-transfer kinetic properties that permit more rapid separations of macromolecules. The utility of the new Poroshell column packing is demonstrated with separations of proteins and synthetic polymers.