Table 5: The main wavelengths in FTIR functional groups of HYOOA and OLHYOOD.

Wavelength of HYOOAaWavelength of OLHYOODbFunctional groups

34133445OH stretching (alcohol)
30033003C=C bending vibration (aliphatic)
2925, 28552925, 2554C–H stretching vibration (aliphatic)
17371738C=O stretching vibration (ester)
1711C=O stretching vibration (carboxylic acid)
14611461C–H scissoring and bending for methylene group
1176, 11171173,1117C–O stretching vibration (ester)
1279C–O stretching assymmetric (carboxylic acid)
967967C–H bending vibration (alkene)
723723C–H group vibration (aliphatic)

Notes: 9(12)-hydroxy-10(13)-oleioxy-12(9)-octadecanoic acid (a); oleyl 9(12)-hydroxy-10(13)-oleioxy-12(9)-octadecanoate (b).