ARS | Publication request: USE OF AN EVAPORATIVE LIGHT SCATTERING DETECTOR COUPLED TO MALLS FOR DETERMINATION OF POLYSACCHARIDE MOLECULAR WEIGHT

Submitted to: Journal of Liquid Chromatography and Related Technologies
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 22, 2005
Publication Date: February 1, 2006
Repository URL: http://www.ars.usda.gov/sp2UserFiles/Place/66210000/Reprint958.pdf
Citation: Luzio, G.A. 2006. Use of an evaporative light scattering detector coupled to malls for determination of polysaccharide molecular weight. Journal of Liquid Chromatography and Related Technologies. 29:185-201.

Interpretive Summary: Knowing the size of molecules and charge characteristics is important to understand how they behave in industrial applications. Usually these determinations are made under conditions where the charge characteristics are not taken into consideration while measuring the molecular weight. This is because of the difficulty in performing molecular weight determinations with changing salt concentrations to separate molecules based on charge. This work describes a technique for performing the molecular weight determination while separating the molecules based on charge.

Technical Abstract: A method to calibrate and use an evaporative light scattering (ELS)detector as a mass detector for molecular weight determination of polysaccharides using multi-angle laser light scattering detector (MALLS) is described. The calibration of the ELS detector is performed under isocratic conditions using values obtained from an interferometer refractive index (RI) detector. A main limitation to doing molecular weight determinations under non-isocratic conditions is due to the difficulty in using the RI detector under these conditions as a mass detector. Without baseline adjustment the ELS detector is used to determine mass at elevated buffer concentrations to simulate a step gradient.