Analysis of Fatty Acids in Cottonseed Oil Using Two Different Esterification Methods by Gas Chromatography Mass Spectrometry

The cottonseed oil was extracted by Soxhlet extraction. The fatty acids in the cottonseed oil were esterified by two methods and analyzed by gas chromatography mass spectrometry (GC/MS). The components and their contents of the fatty acids were compared with each other. The results showed that 11 fatty acids were identified by esterification method 1 and 7 fatty acids were identified by esterification method 2, the contents of the identified fatty acids make up 96.16% and 98.32% of the cottonseed oil respectively. A comparison of the major fatty acids was made: the major fatty acids were hexadecanoic acid (27.26%), 9,12 octadecadienoic acid (40.24%) and 9 octadecenoic acid (14.27%) by esterification method 1; the major fatty acids were hexadecanoic acid (27.12%), 9,12 octadecadienoic acid (48.00%) and 9 octadecenoic acid (15.51%) by esterification method 2.