Model-independent aspects of hydrodynamic chromatography theory

Model-independent chromatography theory relates the speed of chromatographic transients to equilibrium properties. In hydrodynamic chromatography (HDC), colloidal particles migrate slightly faster than the carrier fluid in which they are suspended. It is shown that this (not necessarily equilibrium) process may be related to the properties of a colloidal suspension in equilibrium near an interface. All of the salient aspects of HDC may be explained satisfactorily by assuming that the principal interactions between the colloidal particles and the interface are via double-layer and van der Waals forces. The structure of the theory is such that other forces or different energy expressions may be incorporated easily.