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. Quick quantitative HSQC (QQ-HSQC) NMR was applied to the quantitative evaluation of different inter-unit linkages in lignins (see figure) by using the guaiacyl C2 and syringyl C2-C6 signals as internal standards. The advantage of QQ-HSQC NMR analysis of lignin is the detection and quantification of lignin inter-unit linkages by a direct, non-destructive method with short acquisition times. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.