Fig. 2.

¹H NMR spectra of 25 chemical compounds identified from the liquors of pre-treated rice husk and rice straw. Four severities (severities 1.57, 3.65, 5.15, 5.45) were selected as examples to present the identification method. The complete spectra were split into two main parts (a, b), which were further divided into several fragments and scaled differently to indicate compounds produced at low level. The red lines show the chemical shift (-ppm) scale with chemical shifts of individual compounds indicated on the figure