BS EN 14104:2021 pdf download.Fat and oil derivates – Fatty acid methyl ester ( FAME ] -Determination of acid value.
BS EN 14104 specifies a titrimetric method for the determination of acid value in light coloured Fatty
Acid Methyl Esters, hereinafter referred as FAME.
It allows the determination of acid value within a range of
NOTE 1 For the purposes of BS EN 14104, the terms are used to represent
respectively the mass fraction and the volume fraction.
NOTE 2 For oils and fats the determination of acid value is specified in EN ISO 660 [1].
WARNING — The use of this document can involve hazardous materials, operations and equipment. BS EN 14104 does not purport to address all of the safety problems associated with its use. It is the responsibility of users of BS EN 14104 to take appropriate measures to ensure the safety and health of personnel prior to the application of the document, and to determine the applicability of any other restrictions for this purpose.
Use only reagents of recognized analytical grade and water of grade 3 in accordance with EN ISO 3696.
5.1 Toluene.
5.2 Isopropanol.
5.3 Solvent A for solvent mixture (5.5), ethanol, 95 % (V/V) -97% (V/VJ purity.
5.4 Solvent B for solvent mixture (5.5), diethyl ether, peroxide free, stabilized with butylated hydroxytoluene (BHT).
5.5 Solvent mixture, mixture of equal volumes of solvent A (5.3) and solvent B (5.4).
Neutralize, just before use, by adding the potassium hydroxide solution (5.8) in the presence of 0,3 ml of phenolphthalein alcoholic solution (5.9) per 100 ml of solvent mixture.
If it is not possible to use diethyl ether, a mixed solvent may be used as follows:
— toluene (5.1) and ethanol (5.3), 1 + 1 mixture by volume;
Weigh, to the nearest 0,000 1 g, approx. 180 mg of potassium hydrogen phthalate (5.6) or approximately 100 mg of benzoic acid (5.7), in a 300 ml flask and dissolve in 100 ml of distilled water. Carry out titration using KOH 0,1 mol/l solution (alcoholic or water solution), using phenolphthalein solution (5.9) as an indicator. At the end point the colour of solution turns to a persisting pink.
Potassium hydrogen phthalate and benzoic acid dissolve slowly in water: carefully check that the sample is completely dissolved before starting the titration.
The concentration of the potassium hydroxide solution, expressed in moles per litre, (when potassium hydrogen phthalate is used), is given by.BS-EN-14104-2021