This part of ISO 12966 specifies a method for the determination of fatty acid methyl esters (FAMEs) derived by transesterification or esterification from fats, oils, and fatty acids by capillary gas chromatography (GLC). Fatty acid methyl esters from C4 to C24 can be separated using this part of ISO 12966 including saturated fatty acid methyl esters, cis- and trans-monounsaturated fatty acid methyl esters, and cis- and trans-polyunsaturated fatty acid methyl esters. The method is applicable to crude, refined, partially hydrogenated, or fully hydrogenated fats, oils, and fatty acids derived from animal and vegetable sources, and fats extracted from foodstuff. Milk and milk products (or fat coming from milk and milk products) are excluded from the scope of this part of ISO 12966. This part of ISO 12966 is not applicable to di-, tri-, polymerized and oxidized fatty acids, and fats and oils. A method for the determination of the composition of fatty acid methyl esters expressed by area % in liquid vegetable oils is proposed in Annex E.