Liquid Chromatography Detectors - Liquid Light Scattering Detectors > The Multiple Angle Laser Light Scattering (MALLS) Detector > Page 80

Figure 52 Determination of Molecular Weight from Low Angle Light Scattering Measurements

The detector sensitivity appears to be similar to that of the refractive index detector and with about the same linearity. However, the greatest advantage of this detector is that it can provide molecular weight data for extremely large molecules.

The Multiple Angle Laser Light Scattering (MALLS) Detector

The multiple angle laser light scattering detector differs from the low angle device, in that scattering measurements are made at a number of different angles, none of which are close to the incident light. This significantly reduces problems associated with light scattering from particulate contaminants. Data taken at different angles to the incident light allows the root-mean-square (rms) of the molecular radius  to be calculated in addition to the molecular weight of the substance. The relationship that is used is as follows: