ARS | Publication request: Determination of Molecular Weight Citrus Pectin Using Ion Chromatography

Submitted to: Florida State Horticultural Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2006
Publication Date: June 4, 2006
Citation: Luzio, G.A. 2006. Determination of molecular weight citrus pectin using ion chromatography. Florida State Horticultural Society Meeting. Paper No. 56.

Technical Abstract: Objective was to investigate the use of ELS as a mass detector coupled with MALLS for determining the molecular weights of pectins and other polysaccharides under changing buffer concentrations using HPLC. This would permit the direct determination of the charge to size ratio of pectin which is important for many applications involving pectin. For calibration of the ELS, the chromatography 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) at for the concentration response of the RI versus the voltage response of the ELS. 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 under gradient conditions.