Table 4.

Identification of functional groups associated with the observed FTIR spectral peaks^49,55–57.

Wavelength (cm− 1)	Functional group
3440–3700	Free O-H (Alcohol group)
3150–3420	O–H stretch in Alcohol or Carboxylic acid, N–H stretch in Amines
3000–3150	C–H stretch in aromatic
2930–3000	CH3 asymmetric stretch
2865–2930	CH2 asymmetric stretch
2790–2865	CH2 symmetric Stretch
1650–1720	carbonyl C = O stretch
1570–1650	aromatic C = C stretch
1380–1570	C–H bend or scissoring in Alkane
1345–1380	C–H rock in Alkane
1240–1320	C-O stretching
1053–1240	C-O-C stretching in ether
920–1053	Stretching of S = O bond in sulfoxides
750–920	C-H bending in aromatic ring
650–750	C-H in long chain alkane