High-performance liquid chromatography of proteins using chemically-modified silica supports

Summary Highly efficient and fast exclusion-chromatographic separations of proteins are possible on chemically-modified, silica stationary phases. By optimizing the pH and the ionic strength of the aqueous eluent secondary interactions of the samples with surface groups can be excluded. Bonded propylamide groups proved to possess optimum properties for exclusion chromatography. With other functional groups adsorption effects cannot be excluded totally. The optimum pore size distribution for protein separation up to relative molecular masses of 500,000 daltnons is between 10nm and 50nm. With these silica-based phases the pore size distribution, the pore volume and the packing characteristics are independent of the eluent, therefore the same column can be used with aqueous as well with organic eluents. It is possible to correlate the elution volume (molecular size) of proteins with those of polystyrene standars. The recovery of the proteins and their biological activity has always been better than 90%. The potentialities of adsorption chromatography of proteins on chemically-bonded stationary plases with different functional groups are demonstrated.