The peaks in the fingerprint were assigned [32–35] : 3670/3580 cm − 1 (1) for O–H stretching in alcohol (cellulose, hemicellulose), 2940/2920 cm−1 (3) for C–H antisymmetric stretching vibration in cellulose, 1645/1630 cm − 1 (4) for C N vibration in amides, 915/905 cm − 1 (7) for CH 2 and C–H stretch in olefin compounds, 880/855 cm − 1 (8) for –CO 3 2 − deformation in carbonates, 735/675 cm−1 (9) for C–H deformation in olefin compounds, 659/583 cm − 1 (10)for O–H stretch in carbohydrates, 472/467 cm − 1 (11) for Si–O stretching vibration in silicates and silica.