Polydisperse nature of lignosulfonates

Spruce lignosulfonates, in the molecular weight range 7000 to 22,000, have been shown to be highly polydisperse and do not comprise an homologous series. In the range 7000 to 13,000 the sulfonate content is proportional to the surface area of the molecule. The methoxyl content, relative to the nonmethoxyl carbon, is constant in the molecular weight range 7000 to 22,000 and close to 1. 0 per C//1//0 unit. Recommendations for the gel permeation chromatography in fractionation of ligninosulfonates are given.