Molecular weight: light scattering method

Methods used for molecular weight light-scattering, LS end group, E SD,... 

Absolute calibration is of critical importance for the determination of molecular weights by the light-scattering method. The scattered intensity is so low compared with the incident beam at a distance of a few cm. being of the order of 10 lo) that a reliable direct comparison of the two beams using the same photocell is impractical. Several methods have been used, with results which are not always comparable, however. 

Cabannes factor analy chem An equational factor to correct for the depolarization effect of the horizontal components of scattered light during the determination of molecular weight by optical methods. ko banz. fak-tor cacodyl orgchem (CH3)2As A radical found in, for example, cacodylic acid, (CH3)2A-sOOH. kak-3 dil ... 

Which will yield the higher apparent molecular weight values in the light-scattering method (a) a dust-free system or (b) one in which dust particles are present ... 

The determination of molecular weights by the light scattering method is based on the principle that the intensity of light scattered at some angle, 6, is a... 

Thus the light scattering method measures the weight average molecular weight of the solute. (This was pointed out in Section 2.9.)... 

Methods of measurement (o) = osmotic pressure of the acetylated glycogen (s) = sedimentation-diffusion, (1) = light-scattering. Methods of assay (m) = methylation (p) = periodate oxidation. This specimen was polydisperse, a minor component having a molecular weight of 0.3 X 10. These invertebrates are commonly known as fresh-water mussel, common mussel, cockle, and edible snail, respectively. Fractionation by electrodialysis. This specimen was polydisperse minor components had molecular weights of 12.9 X 10 and 0.3 X 10. ... 

Ultracentrifugation experiments yield Mz values. They are used primarily for biological polymers. The random coil conformation of most synthetic polymers in solutions makes it difficult to interpret these data and this method is little used with such materials. Among the absolute methods of molecular weight determination, only the osmotic method and the light scattering method are given primary consideration in this chapter. 

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