What is MALS detector?
A multi angle light scattering (MALS) detector is a form of static light scattering detector which allows the absolute molecular weight (Mw) and potentially the radius of gyration (Rg) of a sample to be measured.
What does SEC-MALS stand for?
The most commonly known version is SEC-MALS (sometimes also referred to as SEC-MALLS for multiple angle laser light scattering). MALS measures the light scattered by the samples at a range of angles and then extrapolates back to zero degrees.
What is MALS used for?
Multiangle light scattering (MALS) describes a technique for measuring the light scattered by a sample into a plurality of angles. It is used for determining both the absolute molar mass and the average size of molecules in solution, by detecting how they scatter light.
What is Rayleigh ratio?
The Rayleigh ratio is one of the most important quan- tities to determine the mass-average molecular mass (Mw) of polymers by static light scattering. For accu- rate determination of the ratio, accurate optical geom- etries are required.
What is refractive index detector used for?
A differential refractometer (DRI), or refractive index detector (RI or RID) is a detector that measures the refractive index of an analyte relative to the solvent. They are often used as detectors for high-performance liquid chromatography and size exclusion chromatography.
What is SLS light?
Static light scattering (SLS) is a technique to measure absolute molecular weight using the relationship between the intensity of light scattered by a molecule and its molecular weight and size, as described by the Rayleigh theory.
What is RI analysis?
Refractive index (RI) detection is commonly used for the analysis of compounds that do not have good absorption bands for UV light. For such compounds, other detection techniques can be used as well, such as MS or evaporative light scattering detection (ELSD).
What is multi-angle light scattering?
The following theory section contains a brief overview of the following topics related to multi-angle light scattering: When laser light impinges on a macromolecule, the oscillating electric field of the light induces an oscillating dipole within it.
What are the different types of light scattering techniques?
The most widely used light scattering techniques are SLS, multi-angle light scattering (MALS), and DLS. Another technique, electrophoretic light scattering, is used for the measurement of zeta potential, which is a key physical property of any particle dispersed in a liquid environment.
Why use astra for light scattering analysis?
ASTRA’s band-broadening correction results in the expected uniform molar mass values across protein monomer, dimer and trimer peaks, without ‘ringing’ seen in other light scattering analysis software. The workflow in ASTRA is straightforward and can even be fully automated with One-click MW™.
How many scattering angles can be measured with a Litton detector?
The application of the Litton detector by Salzman et al. provided measurement at 32 small scattering angles between 0° and 30°, and averaging over a broad range of azimuthal angles as the most important angles are the forward angles for static light scattering.