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Handbook of Size Exclusion Chromatography and Related ...

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egular SEC column in which the pore volume is roughly 30 to 40% <strong>of</strong> the entire<br />

column volume. In the curve, the linear portion above 3 10 5 is due to the HdC<br />

mechanism separating large molecules while the portion below 5 10 4 is due to<br />

the SEC mechanism separating lower MW species. It can be seen that the portion<br />

<strong>of</strong> the curve due to the SEC mechanism has a flatter slope than that region due to<br />

the HdC mechanism. In order to obtain a linear calibration curve over the entire<br />

MW range, the total pore volume must be reduced so that the slope <strong>of</strong> the lower<br />

MW portion <strong>of</strong> the curve matches that <strong>of</strong> the upper region. From experience, the<br />

ratio <strong>of</strong> the total pore volume to total column for such an ideal SEC/HdC column<br />

should be roughly one-third that <strong>of</strong> a regular SEC column.<br />

Figure 9 Calibration curve <strong>of</strong> SE/HdC. Column, 10mm solid-bead column<br />

(250 10mm) þ 5mm PLgel MIXED-D column (300 7:5mm); mobile phase, THF<br />

with 250ppm BHT, at 0.5mL/min; column temperature, 508C.<br />

© 2004 by Marcel Dekker, Inc.

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