Detection of muconic acid type structures in oxidised lignins using 2D NMR spectroscopy 10^th EWLP, Stockholm, Sweden, August 25–28, 2008

Abstract

Abstract The identification of muconic acid type structures (MATS) in oxidised lignins employing 2D NMR spectroscopy was carried out. The primary database for MATS detection by single bond 1 H- 13 C (HSQC) and long-range 1 H- 1 H and 1 H- 13 C correlation (COSY and HMBC) NMR experiments was obtained with a series of model compounds: cis, cis - and trans, trans -muconic acids and their methylated analogues and MATS derived from monomeric lignin model compounds oxidised by ClO 2 . Additional information was obtained from the study of oxygen-organosolv lignin obtained from spent liquor after the spruce wood delignification with oxygen in an acetone-water solution. This work allowed the reliable assignment of MATS signals in the HSQC spectra of oxidised lignin and provides a methodology for detection and distinguishing of MATS from structurally similar moieties.