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.
NOTE Dienes, such as cis-trans and trans-trans dienes, can affect the calibration.
For accurate determinations on materials with trans levels below 5 %, a standardized capillary GLC method is
recommended (for example, see ISO 15304).
Diese Internationale Norm legt ein Verfahren für die genaue Bestimmung isolierter trans-Bindungen in natürlichen oder bearbeiteten langkettigen Fettsäuren, Fettsäureestern und Triglyceriden mit einem Gehalt an trans-Isomeren über 5 % fest.