Supelco, Inc.

S.a.c. Corporation

Binyamin Feibush

Nai-Hong Li

Daryl John Gisch

Novel packing materials are provided for liquid chromatography and/or solid phase extraction columns which will allow direct injection of biological fluids. These packing materials have a hydrophilic exterior layer and a hydrophobic, charged or otherwise selective portion that forms an underlayer or is embedded in the hydrophilic layer. During a chromatographic process large water soluble biopolymers will be in contact with the hydrophilic outer layer and be shielded from interacting with the underlayer or embedded portion and elute unretained. Small analytes, on the other hand, can be fully partitioned throughout the exterior and interior layers and are retained by hydrophobic or electrostatic interactions. Using such packings the direct analyses of plasma or serum for drug analysis is demonstrated.

Shielded stationary phases

Silica gel chromatographic supports surface-modified with (R.sup.1 O).sub.3-m Si R.sup.2.sub.m(CH.sub.2).sub.3 NH(CH.sub.2 CH.sub.2 NH).sub.n H, in which R.sup.1 is a C.sub.1 -C.sub.5 alkyl, R.sup.2 is methyl or ethyl, and m and n are independently selected from the integers 0, 1 or 2, and further modified chemically to produce reverse-phase character, markedly reduce the interaction between silanophilic analytes and the silanol groups present on the surface of the silica gel through the presence of polar groups, which include the residual unmodified amino and modified amino groups, and which are densely packed near the silica surface. This results in chromatographic elution of basic, silanophilic analytes in efficient, narrow bands similar to those of the less-polar analytes.

Deactivated supports for liquid chromatographic separation of

Porous, rigid resin particles are prepared having a predetermined particle size distribution, surface area and porosity by polymerizing in the pores of porous inorganic template particles a reaction mixture comprising monovinyl monomers, polyvinyl crosslinking monomers and a polymerization initiator in a liquid medium in which the monomers and initiator are phase separable and extractable therefrom into the pores of the template particles. The extracted mixture is polymerized in the pores of the template particles, and the template particles are removed without destruction of the polymerizate. The isolated polymerizate mirrors the characteristics of the template particles. The surface of the polymerizate may be modified in various ways to contain desired functionality. The particles of the invention are useful in chromatography, adsorption, ion exchange, and in catalysis.

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State College, PA, United States of America

Binyamin Feibush