Historical aspects of solute partitioning effects in SEC

Modern theoretical models used to describe SEC elution behavior must allow for possible variations in both the solute and bead pore size and shape, while remaining consistent with current concepts regarding SEC as an equilibrium controlled process. SEC, then, may be explained on the basis of purely geometrical arguments (ref. 16). We shall examine the historical development of these models next. 

The earliest efforts at the characterization of solute behavior during SEC utilized plots of log M versus some function of the elution volume, V. A volume parameter commonly used for these plots was which was easily derived (refs. 7,17 and 18) from the relationship for chromatographic partitioning (equation 1) and is shown below. 

Current theories of equilibrium steric behavior of solutes in SEC are based on three general variations of solute form these are the spherical, rodlike and random-coil solute models. The equilibrium constant, (or usually K, 

Early theories of hard sphere solute models, in chronological order of appearance, include the random-spheres pore model of Ogston (ref. 19), the 

Although of more interest to the study of small molecule elution than to 

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