EN 14111 Fat and oil derivatives - Fatty Acid Methyl Esters (FAME) - Determination of iodine value
5 Reagents
Use only reagents of recognised analytical grade and water of grade 3 in accordance with EN ISO 3696.
5.1 Potassium iodide (KI), 1 00 g/l aqueous solution free from iodate and iodine.
5.2 Starch solution
Mix 5 g of soluble starch in 30 ml of water and add to 1 000 ml of boiling water. Boil for 3 min and let stand to cool.
5.3 Sodium thiosulfate, standard volumetric solution in water, c(Na2S2O3•5H2O) = 0.1 mol/l standardized not more than seven days before use.
5.4 Solvent, prepared by mixing equal volumes of cyclohexane and glacial acetic acid.
5.5 Wijs reagent, containing iodine monochloride in acetic acid.
The I/Cl ratio of Wijs reagent shall be within the limits 1.10 +/- 0.1.
NOTE Commercially available Wijs reagent can be used.
6 Apparatus
Usual laboratory equipment and, in particular:
6.1 Glass weighing scoops, suitable for the test portion and for inserting into the flask (6.2).
6.2 Conical flasks, 500 ml capacity, fitted with ground glass stoppers and completely dried.
6.3 Analytical balance, capable of weighing with an accuracy of +/- 0.001 g or less.
7 Sampling
Sampling is not part of the method specified in this European Standard. A recommended sampling method is given in EN ISO 5555.
It is important that laboratory receives a sample which is truly representative and has not been damaged or changed during transportation and storage.
8 Preparation of test sample
Prepare the test sample in accordance with EN ISO 661. The test sample shall not be heated and/or filtered.
