Non-Destructive Determination of Lignin Syringyl/Guaiacyl Monomeric Composition in Native Wood by Fourier Transform Raman Spectroscopy

Abstract

The feasibility of using FT-Raman spectroscopy for rapid non-destructive determination of lignin syringyl/guaiacyl (S/G) monomeric composition was examined using Eucalyptus camaldulensis and E. globulus, including samples of various ages and colors, which are of importance as a plantation source. The application of 2nd derivatives transformation of Raman spectroscopic data revealed highly significant correlations between wet chemical and Raman predicted values with correlation coefficient (r) = 0.998 and standard error of prediction (SEP) < 0.07 points in the calibration (for known samples), and r = 0.935 and SEP < 0.32 points in the prediction (for unknown samples), respectively. Consequently, this nondestructive method has proved its validity for analyzing Eucalyptus native wood meal samples, regardless of their age and color to determine lignin S/G monomeric composition. Using FT-Raman spectroscopy, elite tree selection based on quality aspects for pulp and paper production can be performed.