Handbook of Size Exclusion Chromatography and Related ...

Figure 1 “Bridge design” flow-referenced capillary viscometer. See text for details.
(Adapted from Ref. 6, with permission from John Wiley and Sons, Inc.)
polystyrene standards. Note that the refractometer is proportional to
concentration c; the signal from the viscometer is proportional to [h]c. By
dividing the viscometer output by the refractometer signal, we can then determine
[h] at each elution volume increment.
2.2 Light Scattering
The intensity of the light scattered by a polymer solution, above that scattered by
the pure solvent, is related to the molecular weight of the polymer by (9)
K*c
R(u) ¼
1
MwP(u) þ 2A2c (6)
where c ¼ polymer concentration, Mw ¼ weight-average molecular weight of the
polymer, A2 ¼ second virial coefficient of the polymer–solvent system, R(u) ¼
measured excess scattering intensity of the solution over that of the pure solvent,
the Rayleigh ratio, P(u) ¼ particle scattering function as a function of angle
relative to the incident beam, and K* is an optical constant for the scattering
system, given by
© 2004 by Marcel Dekker, Inc.
K* ¼ 4p2 n 2 0 (dn=dc)2
l 4 0 NA
(7)