BS EN ISO 12966-3:2009 Animal and vegetable fats and oils. Gas chromatography of fatty acid methyl esters. Preparation of methyl esters using trimethylsulfonium hydroxide
BS EN ISO 12966-3 specifies a rapid base-catalysed transesterification method for fats and oils with trimethylsulfonium hydroxide (TMSH) to prepare fatty acid methyl esters. The method is exclusively applicable to the preparation of methyl esters of fats and oils for gas liquid chromatographic (GLC) analysis. It is applicable to all fats and oils including milk fat and blends containing milk fat. Isomerization of unsaturated fatty acids only occurs to a minor extent and isomerized fatty acids are only present at the determination limit.
As isomerization 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.
This part of BS EN ISO 12966 is based upon German Standard Method C-VI 11e (98).
Contents of BS EN ISO 12966-3:
1 Scope
2 Normative references
3 Principle
4 Reagents
5 Apparatus
6 Sampling
7 Preparation of the test sample
8 Procedure
9 Test report
