Wavenumber/cm−1

Assignment

Representative compounds

3415.69

-OH vibration and N-H stretching vibration

Carbohydrates including cellulose, hemicellulose, and lignin and water

2926

Symmetric or asymmetric stretching vibrations of C-H in -CH3 and -CH2

Polysaccharides, lignin, fatty acids and saturated hydrocarbons

1737

Stretching vibration of C=O in non-conjugated ketones, carbonyl groups and esters

Polysaccharides, lignin, and hemicellulose

1654

Stretching vibration of C=O in p-substituted conjugated aromatic groups

Lignin

1617

Stretching vibration of C=O and skeletal vibration of aromatic groups

Lignin

1516 and 1513

Deformation of N-H and stretching vibration of C=N

Aminos and lignocellulose

1445

Bending vibration of C-H and skeletal vibration of benzene ring

Lignin and polysaccharides

Lignin

1236 and 1261

Stretching vibration of CO-OR and Ph-O

Acetoxy group in hemicellulose and lignin

1049

Asymmetric stretching vibration of Si-O-Si and stretching vibration of C-O

Silicic compounds cellulose, polysaccharides, lignin, and hemicellulose