The oil has a strong absorption at 2926 cm1
due to C–H stretching vibrations of hydrocarbon.
Medium absorption peaks occurred at 1368 cm1 (C–O stretching vibrations of
carboxylic acid), 1448 cm1 (C–O–H vibrations of carboxylic acid),
1645 cm1 (aromatic ring) and 1713 cm1 (C@O vibrations of acid)
[13,15,22,31–34].