Handbook of Size Exclusion Chromatography and Related ...

Figure 5 ElutionbehaviorofpolystyrenestandardsinTHFinpacked-columnHdCwith
different packing diameters: B ¼ 1.40mm, O ¼ 1.91mm, and V ¼ 0.87mm. Theoretical
curves (dashed lines). (From Ref. 6, Copyright 1990, Elsevier.)
1.40, 1.91, and 2.69mm solid beads are shown in Fig. 5(6). The dashed lines in
Fig. 5are theoretical curves.
3 COMPARISON OF HdC AND SEC
The separation range of an SEC column, in terms of MW,is determined by the
pore size of the packed gels. The calibration curves of columns with single poresize
gels are shown in Fig. 6(7). Abroader MW range of separation can be
obtained by mixing various pore size gels. The slope of the calibration curve, or
resolution of separation, then depends on the pore volume. The greater the pore
volume, the less steep will be the calibration curve, and the better the resolution;
and viceversa. Alinear calibration curvewith broad separation range in MW can
be achieved by packing specially-mixed different pore-size gels of the same
particle size in acolumn. Linear calibration curves with various MW ranges of
commercialized mixed-bed columns are shown in Fig. 7(8). In the HdC case,
optimal chromatographic separation requires aclose packing, uniform particle
size,andassphericalgelsaspossible.Giventheseconditionsthecalibrationcurve
dependsonlyontheparticlesize.TheMWseparationrangeofanHdCcolumn,as
© 2004 by Marcel Dekker, Inc.