Elucidation of lignin structure by quantitative 2D NMR.

Quick quantitative HSQC (QQ-HSQC) was applied to quantitative evaluation of different inter-unit linkages in an array of milled softwood and hardwood and technical lignins by using the guaiacyl C2 and syringyl C2-C6 signals as internal standards. The results were found to be highly reproducible and comparable with earlier literature reports. The advantage of QQ-HSQC NMR analysis of lignin is contemporary detection and quantification of lignin inter-unit linkages with a direct, non-destructive method requiring short acquisition times.