Continuous beds for microchromatography: Chromatofocusing and anion exchange chromatography

A method was developed for the preparation of continuous beds derivatized w ith polyethyleneimine (PEI) for chromatofocusing and anion exchange chromat ography in the capillary mode. First, a continuous bed activated by epoxy g roups was synthesized inside a fused silica capillary and became at the sam e time covalently attached to the inner wall of the capillary. A PEI soluti on was then pumped through the continuous bed to allow the imine groups in PEI to react with the epoxy groups in the bed. Efficient immobilization of PEI was indicated by the high-resolution separation of standard proteins (h emoglobins C, S, F, and A) in both chromatofocusing and anion exchange chro matography on a capillary column prepared by this method. (C) 1999 Academic Press.