Measurement of absolute molecular weight and molecular weight distribution.
Malvern’s systems support two fundamental ways of measuring the molecular weight of polymers and proteins in solution.
Measuring molecular weight using static light scattering (SLS)
In this technique the total amount of light scattered by the sample is measured by a sensitive detector at a particular scattering angle.
- No calibration is required, so the result is an absolute value.
- Detectors are available for SEC/GPC to give true molecular weight distributions.
- A cuvette based system such as the Zetasizer µV or the Zetasizer Nano series can be used to give a weight average molecular weight.
Measuring molecular weight using dynamic light scattering (DLS)
This technique measures the size of the molecule, and converts this to an estimated molecular weight using a selected model such as protein, dendrimer or linear polymer for example.
- Very small volumes of sample are required, as little as 2µL.
- The measurement is very fast, a couple of minutes per measurement.
A molecular weight distribution can be calculated, although separations of oligomers, e.g. monomer – dimer - trimer are not possible.
Molecular weight products
- Sample type:
- Polymer, Protein & Biopolymer
- Temperature range:
- Ambient to 160°C
- Size Exclusion Chromatography