Iodine value means the “g” value of halogen which adhere to g of methods such as Hanus method and Wijs method for Iodine value. The processors of oil and fat are in need of a quick determination method of iodine value of oils and fats especially in case of checking the degree of. This test method covers the determination of the iodine value of fats and iodine value of fats and oils that do not contain conjugated 3 Wijs Solution ( Iodine Monochloride Solution) may be purchased commercially. 1.
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Iodine value – Wikipedia
So it is important to know the extend to which a fatty acid is unsaturated. For reproduction of material from all other RSC journals and books: These fatty acids can be classified into saturated or unsaturated based on the number of double bonds present in the fatty acid.
This particular analysis is an example of iodometry. The fat is mixed with an excess of bromine. The Wijs method as the standard for iodine absorption.
Already metjod an account? Retrieved from ” https: March 17, Released: Valuf and Green modified the Wijs’ method by employing mercuric acetate as catalyst and made it possible to determine the iodine value of a sample in ten minutes or so. This unsaturation is in the form of double bondswhich react with iodine compounds. This reaction must be carried out in the dark, since the formation of bromine radicals is suppressed by light. May 07, accepted: Back to tab navigation Fetching data from CrossRef.
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Iodine value or number is the number of grams of iodine consumed by g of fat. Previous article Next article.
Iodine numbers are often used to determine the amount of unsaturation in fatty acids. Fetching data from CrossRef.
Information about reproducing material from RSC articles with different licences is available on our Permission Requests page. This bromine is added to the double bonds in the unsaturated fats.
A higher iodine value indicates a higher degree of unsaturation.
The Wijs method as the standard for iodine absorption – Analyst (RSC Publishing)
Bromination of the double bonds in the dark, reducing the excess bromine with iodidebacktitration of iodine with thiosulfate. Starch is used as the indicator for this reaction so that the liberated iodine will react with starch to give purple coloured product and thus the endpoint can be observed. Saturated fatty acids will not give the halogenation reaction. They are likely to exists as liquids at room temperature. Journal of Oil Chemists’ Society, Japan. If you are the author of this article you still need to obtain permission to reproduce the whole article in a third party publication with the exception of reproduction of the whole article in a thesis or dissertation.
The chemical reaction associated with this method of analysis involves formation of the diiodo alkane R and R’ symbolize alkyl or other organic groups:.
Trans fatty acids are associated with health problems and cardiovascular diseases. Authors have investigated other methods of quick determination of iodine value especially for the oils in the hydrogenation process and have found after all the Wijs’ method could be appropriate by only shortening the reaction time to three minutes for the oils of the iodine value less than about Triglycerides are made up of three fatty acids linked to glycerol by fatty acyl esters.
The iodine value or iodine adsorption value or iodine number or iodine index in chemistry is the mass of iodine in grams that is consumed by grams of a chemical substance.
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