Malvern Zetasizer Nano Series, Руководство пользователя

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Preparing the sample
- Molecular weight
Preparation of a molecular weight sample is similar to that followed for a size
sample, though there are other aspects to consider.
The technique is very sensitive to dirt or dust in the sample and therefore great
care is required in sample preparation. All solvents must be filtered to 0.02µm or
better several times, and the prepared solutions allowed to stand for a period
dependent upon the sample, this may be over 24 hours, to several days to ensure
adequate solvation. All glassware and apparatus
must
be rigorously clean and free
of scratches. Preparation of samples and storage of apparatus in a laminar flow
cabinet to ensure minimisation of dust contamination is strongly recommended.
Failure to carry out these routine procedures are certain to end in a poor or wrong
result.
Very small samples such as proteins in aqueous solutions will often require
filtering.
A number of concentrations of the sample must be prepared (typically 0.25 to 1
gl
-1
). The polymer must be fully soluble and dust must be excluded.
The solvent scattering is measured followed by the various concentrations of
sample. From these measurements a Debye plot can be generated.
C H A P T E R 6
Z e t a s i z e r N a n o S e r i e s
P a g e 6 . 5
Increasing sample concentration
Solvent
1 2 3 4
ILL
6766
Concentration
Intercept point
ILL
6767