Routine analysis of carbohydrates and lignin in herbage

Abstract

Abstract An approximate analytical method is described for the rapid routine determination of carbohydrates and lignin in herbage. Dried milled samples are extracted successively with diethyl ether, 0.5% ammonium oxalate solution, N ‐H 2 SO 4 , and 72% H 2 SO 4 . Soluble carbohydrates in the ammonium oxalate extract are determined with anthrone, and hydrolysed pentosans and hexosans in the combined N ‐H 2 SO 4 and 72% H 2 SO 4 extracts are determined with aniline acetate and chromotropic acid respectively. The method gives a maximum variation of 4% from the mean of duplicates with each carbohydrate component. The residual material is ashed to obtain crude lignin, and a nitrogen correction applied.