Characterization of technical lignins by NMR spectroscopy: optimizationn of functional group analysis by P-31 NMR spectroscopy

摘要

P-31 nuclear magnetic resonance (NMR) based on the derivatization reagent 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane is a common approach for the hydroxyl group determination of lignins, but the results are sometimes less reproducible compared to other methods. In the present work, common pitfalls in P-31 NMR analysis of kraft lignin (KL) and lignosulfonates (LS) are addressed and the results are compared to those obtained by H-1 NMR spectroscopy. Several experimental parameters are rev