The lignin fraction of animal feeding‐stuffs. IV.—The preparation of ‘reference’liganin by extraction with ethyl acetoacetate

Ethyl acetoacetate was found to be a satisfactory solvent for lignin, but not highly selective. The purest'ester lignins' were obtained from the residues after alkali extraction, and when mature plant materials were used these lignins showed little variation in methoxyl content. It is suggested that the percentage of methoxyl in pure lignin is not affected by plant maturity and that the true lignin present in a crude preparation may be determined from the methoxyl content by the use of an appropriate conversion factor.