Table 2.
Assignments of the NIR absorption bands.
| Wavenumber (cm−1) | Type | Feature(s) |
|---|---|---|
| 8403 | combination of the first overtone of the O–H stretching and the OH-bending band (2ν1,3 + ν2) | Water66 |
| 6896 | first overtone of the OH-stretching band (2ν1,3) | Water66 |
| 6674 | first overtone of the OH-stretching band | alcohol or water66 |
| 6307 | first overtone of the OH-stretching band | alcohol or water66 |
| 5935 | C–H stretching first overtone | Lignin67, hemicelluloses67,68 |
| 5787 | C–H stretching (1st overtone) of –CH2 | Carbohydrates69 |
| 5155 | combination of stretching and deformation of the O-H group in water | Water70 |
| 4719 | O-H and C-O stretching combination | Polysaccharide71 |
| 4405 | O-H stretching and C-O stretching combination | Polysaccharides72 |
| 4307 | C-H stretching and C-H2 deformation combination | Polysaccharides66 |
| 4021 | C-H stretching and C-C stretching combination | Cellulose66 |