Determination of Lignin, Cellulose, and Hemicellulose in Plant Materials by FTIR Spectroscopy

A procedure for determining concentrations of lignin, cellulose, and hemicellulose in plant materials using Fourier-transform IR spectroscopy in the middle spectral region was developed and tested. The procedure is based on the use of calibration functions reflecting the dependence of the intensity of analytical absorption bands on the concentration of lignin (1512 cm–1) and cellulose (1450 cm–1) in model samples; for hemicellulose, indirect correlations were used. The model samples were ternary mixtures consisting of lignin, bacterial cellulose, and hemicellulose in various proportions. The proposed method was tested on a wide range of plant biomass samples; it demonstrated adequate precision (RSD no more than 4%). The accuracy of the procedure for determining the main components of plant biomass (lignin, cellulose, and hemicellulose) was demonstrated using the standard addition method.