Improved calibration procedure for gel permeation chromatography of lignins

Abstract

In studying macromolecular properties of lignins, gel permeation chromatography (GPC) is a convenient method for the determination of lignin molecular weights and their distribution. A GPC analytical column was calibrated by preparing narrow molecular weight lignin fractions, then applying the method of Goring and co-workers to obtain molecular weights from the ultracentrifuge at zero concentration and zero field force. Diffusion and other curve-broadening effects in the GPC analytical column were taken into account by applying the correction method of Hamielec and co-workers to derive the coefficients of the calibration curve. The molecular weight of a lignosulfonate sample determined on the GPC was found to coincide closely with that obtained by ultracentrifugation.