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 macromol ecules rather than any type of binding, the feed volume to bed volume ratio is usually quite small. Thus, large columns are typically used in preparat ive- and large scale separations. In this work, a general rate model consid ering various mass transfer effects was successfully used for the scale-up predictions of preparative SEC columns. The effects of various physical par ameters on the performance of SEC were investigated using computer simulati on 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 softw are program. Existing correlations in the literature were used to estimate some mass transfer coefficients in the general rate model. The elution peak s for a large column could be predicted a priori using the method which was tested experimentally in this work. It very accurately predicted the reten tion times and peak shapes of myoglobin and ovalbumin eluted from three pre parative SEC glass columns packed with P60 gel (Bio-Rad Laboratories, Hercu les, CA, USA). The bed dimensions were 4.4 cm(i.d.)x29.5 cm, 5.0cmx29.5 cm, and 5.0cmx42.0cm, respectively. The small column used for the scale-up pre diction had bed dimensions of 1.5 cmx27.3 cm. (C) 1998 Elsevier Science S.A . All rights reserved.