Table 2: Band assignment from average spectrum of naturally seasoned and kiln-dried wood.

Peak no. in Figure 4(b)Wavelength (nm)Bond vibrations

11190–1221Linked to 2nd overtone of CH-stretching and may correspond to CH3 groups of wood constituents such as lignin assigned to spectra and CH, CH2 groups of cellulose
21440Arises from 1st overtone of C-H stretching and C-H deformation in lignin
31447–1491Linked to 1st overtone of O-H stretching in phenolic lignin, glucomannan, and semicrystalline regions in cellulose, intramolecular H-bond of cellulose
41922–1928Related to O-H asymmetric stretching and O-H deformation of the water molecule; this is expected, as the moisture content was different in the specimens
52085–2113Relates to O-H and C-H stretching and deformations in cellulose and xylan molecules
62277Relates to O-H plus C-C stretching and/or C-H stretching and deformation in cellulose; this peak overlaps the peak at 2236 nm related to lignin via C-H stretching and C-H2 deformations
72331Related to C-H stretching and C-H deformation in hemicellulose and xylan molecules
82450–2475Relates to carbohydrates in general