Effect of acid-chlorite delignification on cellulose degree of polymerization.

Two types of pure cellulose, Avicel PH-101 and Whatman filter paper, were treated with an acid-chlorite delignification procedure in the presence of varying amounts of incorporated lignin, and the molecular weight distributions and degrees of polymerization (DP) of derivatized cellulose were determined by gel permeation chromatography (GPC). Avicel samples with 0% added lignin showed a DP reduction of nearly 5% during acid-chlorite delignification, compared to a 1% drop in DP with 30% added lignin. Lignin-free filter paper samples showed a DP reduction of nearly 35% after hollocellulose delignification. This drop in DP was reduced to less than 12% for samples which contained 30% lignin. Thus, the presence of lignin in biomass samples minimized the DP reduction of cellulose due to acid catalyzed cleavage during acid-chlorite delignification.