MICELLAR CHROMATOGRAPHY OF PROTEINS

Proteins were separated on a reversed-phase column with nonionic surfactant/phosphate buffer at neutral pH as mobile phase. Frontal experiments demonstrated the ethoxylated alcohol surfactant was sorbed to the column packing. Caution was required to assure that steady-state conditions were reached so that reproducible chromatography could be performed. As observed with widely used acidic mobile phases containing organic solvents, small changes in additive concentration effected large changes in retention, so that shallow gradients were needed for separations of protein mixtures. Retention of proteins is discussed in terms of van der Waals attraction and repulsion concepts.