Table 4: Explanation of IR spectrograph.

Position/cm−1 Band origin 3400 –OH stretching 2943 C–H stretching 1706 C=O stretching nonconjugated to the aromatic ring 1610 C=O stretching conjugated to the aromatic ring 1520 Aromatic ring vibrations 1462 Aromatic ring vibrations C–H deformations 1275 Aromatic ring vibrations of guaiacyl 1201 C–O stretching of syringy 1124 Aromatic ester 1027 C–H and C–O deformation 820 Syringy C–H vibrations