QUANTITATIVE LIGNIN ANALYSIS BASED ON PERMANGANATE OXIDATION

Aromatic acids obtained on permanganate oxidation of pretreated (cleavage of ethers and alkylation of phenolic groups) lignins offer a possibility to estimate the amounts of differently substituted aromatic units in lignins. An equation is derived to simplify the calculation of the gross composition of lignins based on the yields of methoxy-substituted aromatic acids obtained on permanganate oxidation of lignins with methylated phenolic groups. The fact that only phenolic groups yield degradation acids makes it possible, under certain conditions, to use the equation for the estimation of the phenol content in a lignin sample.