BS EN ISO 3960:2017 pdf download.Animal and vegetable fats and oils— Determination of peroxide value — lodometric (visual) end point determination.
8 Preparation of test sample
Prepare the test sample in accordance with lSO 661.
The test sample for the determination of peroxide value shall be taken first and the peroxide value shallbe determined immediately.
Homogenize the sample, preferably without heating and without aeration.Avoid direct solar radiation.Heat solid samples carefully to 10 °C above their melting point. Samples with visible impurities shall befiltered; the filtration shall be noted in the test report.
For some products, the amount of extracted fat/oil can be lower than 5 g, or the peroxide value ofthe fat/oil can be over 30 meq of active oxygen per kilogram. ln these cases, the user should choose asmaller sample mass [see Clause 12 f)].
9 Procedure
9.1 General
Carry out all steps in diffuse daylight or in artificial light. Avoid direct exposure to sunlight. Observethat all vessels are free from oxidizing or reducing compounds.
Store the sodium thiosulfate standard solutions in amber-stained bottles.
9.2 Preparation and titre determination of the 0,01 N sodium thiosulfate standardsolution
9.2.1 Preparation of the 0,01 N sodium thiosulfate standard solution
By means of a pipette (6.4), transfer 100 ml of the 0,1 N sodium thiosulfate standard solution (5.7)to a volumetric flask of 1 000 ml capacity (6.8). Dilute to the mark with freshly boiled water (5.1).After homogenization, transfer the obtained 0,0i N sodium thiosulfate standard solution to an amber-stained bottle.
