scope:

This International Standard specifies a method for the accurate determination of isolated trans bonds in natural or processed long-chain fatty acids, fatty acid esters and triglycerides with trans isomer levels W 5 %. The method is not applicable, or is applicable only with specific precautions, to .fats and oils containing high levels (over 5 %) of conjugated unsaturation (e.g. tung oil), .materials containing functional groups which modify the intensity of the C-H deformation about the trans double bond [e.g. castor oil containing ricinoleic acid or its geometrical isomer, ricinelaidic acid (12-hydroxy-9-octadecenoic acid)], - mixed triglycerides having long- and short-chain moieties (such as diacetostearin), or in general, - any materials containing constituents which have functional groups which give rise to specific absorption bands at or sufficiently close to interfere with the 966 cm -1 band of the C-H deformation of the isolated trans double bond.