Abstract: The invention provides novel ion-exchange media and related methods for their preparation and use. Ion-exchange stationary phases according to the invention are suitable for chromatographic separation of a variety of biomolecules. Distinguishing characteristics of ion-exchange media according to this invention includes, for example, their ability to separate variants of monoclonal antibodies via cation-exchange liquid chromatography using porous substrates with particle sizes <5 ?m. The ion-exchange stationary media include a hydrolytically stable layer, which inhibits surface degradation of the particles in 100% aqueous media. Another unique feature is low molecular weight building blocks used to functionalize the particles with ion-exchange groups.

Abstract: The present invention provides novel silicon compounds, methods for making these novel silicon compounds, compositions comprising these novel silicon compounds attached to substrates, methods for attaching the novel silicon compounds to substrates and methods for using the compositions in a variety of chromatographic applications.

Abstract: A method for making a weak cation-exchange (carboxylic acid) medium comprising contacting a solution of a functional organic polymer having carbon to carbon double bond unsaturation and having weak cationic exchange functional moieties or precursors thereof in a solvent with a substrate having an organic polymer surface, evaporating said solvent and breaking said double bond under conditions to cause the functional organic polymer to covalently bond to the substrate surface and to cross-link to form a cross-linked functional polymer layer covalently bound to the substrate surface. The medium produced by the method.

Abstract: One embodiment of the invention comprises an ion exchange composition formed by reacting unsaturated carbon to carbon moieties pendant from derivatized ion binding cryptands with a support substrate under free radical activation conditions to form a covalent bond therebetween. In another embodiment, a cryptand ion exchange composition is made by covalently bonding unsaturated carbon to carbon moieties pendant from a derivatized ion binding cryptands with unsaturated carbon to carbon moieties pendant from a support substrate under free radical activation conditions to form covalent bond.

Abstract: Polyfunctional silicon compounds of one of the following formula: in which N-PG is a nitrogen containing function group. Also, such compounds bound to substrates for use as chromatography packing.

Abstract: A modified silica support having a polar phase bound to its surface and suitable for use for chromatograpic separations, having the following formula: 1