Molecular characterization of commercial pectins by separation with linear mix gel permeation columns in-line with multi-angle light scattering detection

Four commercial pectins with different degrees of esterification were analyzed by gel permeation chromatography in-line with multi-angle light scattering and refractive index detectors. Molecular weight distributions and root mean square radii were calculated after elution under different conditions (i.e. mobile phases, flow rates and amounts of pectin injected). Pectins were polydisperse with respect to molecular weight. The molecular weight distribution ranged from 8×103 to 106, depending on the source and was not affected by buffer composition or flow rates of separation. The four pectins had similar values for root-mean square radius of 50 nm.