Fast and simple evaluation of the chemical composition and macroelements of xylem and bark of sweet cherry branches based on FTIR and XPS

Abstract

The branch waste of sweet cherry trees is an organic byproduct that is inevitably produced during the pruning process. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to analyze and compare the differences in the chemical composition and the presence of macroelements of sweet cherry branches. The FTIR absorption spectra were analyzed, and the following absorption peaks were found: 1632 cm-1 for lignin, 1740 cm-1and 1244 cm-1 for hemicellulose, and 1316 cm-1 for holocellulose. The results showed that the lignin content in the bark was higher than that in the xylem, and the content of hemicellulose and holocellulose in the xylem was higherthan that in the bark. The XPS survey showed that the contents of C-C (9.89% and 15.59%, respectively) and C=O (31.52% and 15.59%, respectively) in xylem and bark were quite different; the xylem had a higher cellulose content, while the bark had a higher lignin content. In the xylem, the proportion of C-O was the largest (12.55%), while in the bark, the proportion of C=O was the highest (5.93%). The research results are significant for revealing the chemical composition and structural morphology of the xylem and bark of sweet cherry branches.