ISO/TS 17307:2016 establishes a method for determining the total methyl ester content in fatty acid methyl ester (FAME) by gas chromatography and using an external standard. The method is suitable for biodiesel which contains esters between C6 and C26. This method allows verifying that the total ester content is greater than 96,5 % (m/m). NOTE 1 The method also allows determination of the total ethyl ester content in FAEE, but precision for this has not been established. This Technical Specification does not determine the linolenic nor the poly-unsaturated alkyl ester content. Alternative techniques, such as EN 14103[1] and EN 15779[2], respectively, are available for this. NOTE 2 For the purposes of this Technical Specification, the term "% (m/m)" is used to represent the mass fraction, ?.