Quantitative 31P NMR analysis of solid wood offers an insight into the acetylation of its components

As a solid substrate, wood and its components are almost invariably examined via spectroscopic or indirect methods of analysis. Unlike earlier approaches, in this effort we dissolve pulverized wood in ionic liquid and then directly derive its functional group contents by quantitative (31)P NMR. As such, this novel analytical methodology is thoroughly examined and an insight into the detailed way acetylation proceeds on solid wood and its components is provided as a function of wood density and within its various anatomical features. As anticipated, the efficiency of acetylation was found to be greater within low density wood than in high density wood. The lignin, the cellulose and the hemicelluloses of the low density wood was found to be acetylated nearly twice as fast with remarkable differences in their quantitative degree of acetylation amongst them. This direct analytical data validates the applied methodology and confirms, for the first time, that the order of acetylation in solid wood is lignin>hemicellulose>cellulose and no reactivity differences exist between early wood and late wood.