APPARENT PORE-SIZE DISTRIBUTIONS OF CHROMATOGRAPHY MEDIA

The use of size-exclusion chromatography for determination of pore dim ensions of chromatography media is reviewed. It is noted that many res earchers still use the simple but inaccurate method of treating the se lectivity curve as a cumulative pore size distribution. An alternative procedure for estimation of pore dimensions of media through iteratio n of the apparent pore size distribution to yield elution data in agre ement with experimental data for polymers of known hydrodynamic radius using a simple spread sheet is presented. Data of apparent pore dimen sions of some commercial media for aqueous size-exclusion chromatograp hy is presented. The influence of various parameters, e.g., solute sha pe, pore shape, method errors, etc., is discussed. It is concluded tha t size-exclusion chromatography can not provide information about the pore structure and, thus, the pore size obtained is dependent upon the selected pore model.