Mathematical modeling and scale-up of size-exclusion chromatography

Size exclusion chromatography (SEC) is a widely used tool in bioseparations. Because its separation mechanism is based on the permeability of macromolecules rather than any type of binding, the feed volume to bed volume ratio is usually quite small. Thus, large columns are typically used in preparativeand large scale separations. In this work, a general rate model considering various mass transfer effects was successfully used for the scale-up predictions of preparative SEC columns. The effects of various physical parameters on the performance of SEC were investigated using computer simulation based on the model. A method was developed to scale up SEC columns based on a few simple elution runs on a small column with the same packing to be used in the larger column using a personal computer based simulation software program. Existing correlations in the literature were used to estimate some mass transfer coef®cients in the general rate model. The elution peaks for a large column could be predicted a priori using the method which was tested experimentally in this work. It very accurately predicted the retention times and peak shapes of myoglobin and ovalbumin eluted from three preparative SEC glass columns packed with P60 gel (Bio-Rad Laboratories, Hercules, CA, USA). The bed dimensions were 4.4 cm(i.d.) 29.5 cm, 5.0 cm 29.5 cm, and 5.0 cm 42.0 cm, respectively. The small column used for the scale-up prediction had bed dimensions of 1.5 cm 27.3 cm. # 1998 Elsevier Science S.A. All rights reserved.