DIN EN ISO 12966-3-2010 动物和植物的脂肪和油.脂肪酸甲基酯的气相色谱分析.第3部分:使用三甲基氢氧化硫(TMSH)制备甲基酯
Animal and vegetable fats and oils - Gas chromatography of fatty acid methyl esters - Part 3: Preparation of methyl esters using trimethylsulfonium hydroxide (TMSH) (ISO 12966-3:2009); German version EN ISO 12966-3:2009
This Standard specifies a rapid base-catalyzed transesterification method of fats and oils with trimethylsulfonium hydroxide (TMSH) to prepare fatty acid methyl esters. The method is exclusively usable for the preparation of methyl esters of fats and oils for GLC analysis. It is applicable to all fats and oils including milk fat and milk fat containing blends. Isomerisation of unsaturated fatty acids only occurs to a minor extent and isomerised fatty acids are only present at the determination limit. As isomerisation takes place the procedure is not recommended for Conjugated Linoleic Acid (CLA ). As CLA is not correctly analysed, this method is not applicable to the determination of the complete fatty acid composition of milk fat samples. Only about 70 % to 80 % of the free fatty acids are esterified. In the case of conjugated cyclopropyl and cyclopropenyl fatty acids, side reactions may occur, but these do not interfere with the determination of the fatty acids.