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United States Department of Agriculture

Agricultural Research Service

Title: Evaporative Light Scattering Detector As a Mass Detector with Malls for Determination of Pectin Molecular Weight

item Luzio, Gary

Submitted to: International Light Scattering Colloquium
Publication Type: Abstract Only
Publication Acceptance Date: October 15, 2005
Publication Date: N/A

Technical Abstract: A method to calibrate and use an evaporative light scattering detector (ELS) as a mass detector for molecular weight determination of polysaccharides using a multi-angle laser light scattering detector (MALLS) is shown. The calibration of the ELS was performed under isocratic conditions using concentration values obtained from an interferometric refractive index detector (RI). The observed response fit a power trendline (y = axb) for the concentration response of the RI versus the voltage response of the ELS. The combined average log a coefficient was (5.472, s.d. = 0.020) and the average b coefficient was (1.372, s.d. = 0.004) for all the runs. Band broadening, which could occur between the detectors, was not observed and did not affect the calibration values. Without adjustment the ELS was used as a mass detector for MALLS to accurately determine molecular weights of pectin which had been deesterified with pectin methylesterase with methanol present in the reaction mixture.

Last Modified: 4/19/2015
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