Viscotek has produced a new applications report illustrating how its unique Triple detection-GPC (SEC3) system enables precise and comprehensive characterisation of even complex polysaccharides
In the report two samples identified as branched polysaccharides and one sample identified as a corresponding linear polysaccharide are analysed to determine molecular weight and to analyse branching by SEC3.
The polysaccharide samples in the report were analysed using a Viscotek SEC3 system comprising low angle light scattering (Lals), refractive index and viscometry detectors working in concert.
The report shows that both light scattering and viscometry data is required to unlock molecular weight distribution, viscosity, molecular size and branching frequency data from the highly branched samples.
Low angle light scattering was used to calculate the molecular weights which is extremely important when studying large biomolecules such as polysaccharides where traditional light scattering instruments give large data errors.
Other extrapolation based light scattering techniques, such as those using multi angle detectors, cannot be used because the large molecule sizes result in large data fitting errors.
By comparison the Viscotek Lals detector measures scattered light at 7deg, close enough to zero that the measurement is direct with no need to extrapolate or calculate to get accurate molecular weight and structure data.
