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Handbook of Size Exclusion Chromatography and Related ...

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polymer analysis. Samples are “run” on HPLC instrumentation for practical<br />

reasons only.FIA methods can only determine results that are derived directly<br />

from the overall detector response:<br />

. In the case <strong>of</strong> concentration detectors this would be the concentration<br />

(in most cases not very useful for polymer samples);<br />

. Inthecase<strong>of</strong>light-scatteringdetectors,thiswouldbetheweight-average<br />

molar mass, Mw, determined by asingle concentration only; in multiangle<br />

instruments radius <strong>of</strong> gyration, Rg, <strong>of</strong> certain samples can also be<br />

measured;<br />

. Similarly, in the case <strong>of</strong> viscometer detectors, the only result is the<br />

intrinsic viscosity,[h], determined from asingle concentration only.<br />

Detectorcombinations<strong>of</strong>RI,LS,<strong>and</strong>viscometryallowMw <strong>and</strong>[h]tobeobtained<br />

as before. Mathematical treatment <strong>of</strong> primary information allows the calculation<br />

<strong>of</strong> molecular size from viscosity measurements (16), which the author does not<br />

consider primary (reliable <strong>and</strong> sample independent) information.<br />

Figure 19 ViscosityresultreportbyFIAmethodusingidenticalrawdatasetasinFig.18,<br />

but ignoring distribution information from HighSpeed column.<br />

© 2004 by Marcel Dekker, Inc.

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