On the possibility of quantitative determination of the main components of plant biomass by the method of FTIR spectroscopy

Abstract

A technique for determining the content of lignin, cellulose, and hemicellulose in plant materials using mid-range FTIR spectroscopy in KBr tablets is proposed. The technique is based on the use of calibration functions that take into account the dependence of the intensity of the analyti-cal absorption bands on the content of the corresponding components of plant biomass: lignin (1512 cm–1), cellulose (1165 cm–1), and hemicellulose (1705 cm–1). The calibration functions are constructed using model spectra obtained by adding the IR spectra of lignin, cellulose, and hemicellulose with different weighting factors. The technique was tested on several samples of lignocellulosic biomass. The suitability of the proposed method for determining lignin and hem-icellulose was confirmed by comparing the results with literature data. The method gave overes-timated results for determining cellulose. It has been shown that a more accurate cellulose con-tent can be obtained by subtracting the total lignin and hemicellulose content from 100%