GC-MS Determination of Higher Fatty Acids in Neem Oil

Higher fatty acids were separated from neem oil by either the direct petroleum ether extraction or the CO2-supercritical extraction of the powdered neem seeds.After methylation,methylates of the fatty acids were identified by GC-MS.Same componental fatty acids were found by both of the 2 extraction methods.Quantification of the fatty acids was performed by GC with FID and standard curve method.The main components found were the 8-octadecenoic acid (51.15%),octadecanoic acid (19.13%),hexadecanoic acid (16.78%),7,10-octadecadienoic acid (9.86%) and eicosanoic acid (1.24%).Some other fatty acids,i.e.,cis-3-octyl-oxirane octanoic acid,docosanoic acid,9-octadecenoic acid,11-eicosenoic acid,9-hexadecenoic acid and heptadecanoic acid were also found with their contents under 1%.