Pharmazie 2002-08-01

Determination of iodine values using 1,3-dibromo-5,5-dimethylhydantoin (DBH) without the employment of chlorinated hydrocarbons. Analytical methods of pharmacopoeias with DBH in respect to environmental and economical concern. Part 17.

M Hilp

Index: Pharmazie 57(8) , 538-42, (2002)

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Abstract

Low and medium iodine values of fixed oils and fats can be determined in glacial acetic acid within reduced waiting times of only 5 min. Highly unsaturated compounds such as those of linseed oil, cod-liver oil, sunflower oil, soybean oil, wheat germ oil and the emulsifier sorbitan trioleate result too low values in comparison to PH. EUR. 2002 [2] and USP 2000 [3]. Cocoa butter with a low iodine number is insoluble in glacial acetic acid. The iodine values of nonionogenic emulsifiers such as ceteareth-30 (Macrogol cetostearyl ether PH. EUR. 2002), oleth-10 resp. 20 (Macrogol oleyl ether PH. EUR. 2002) and polysorbate-80 PH. EUR. 2002 are obtained in aqueous solutions. Oleth-2 (Macrogol oleyl ether PH. EUR. 2002), polyoxyl-40 castor oil (Macrolglycerol ricinoleate PH. EUR. 2002), polysorbate-60 PH. EUR. 2002 and sorbitan trioleate PH. EUR. 2002 need the addition of ethyl acetate. Fixed oils even with high iodine values can be determined in an o/w emulsion with a reaction time of 5 min in most cases, when nonionogenic emulsifiers such as ceteareth-30, polyoxyl-30 glycerol monolaurate or polyoxyl-60 hydrogenated castor oil (Macrolglycerol hydroxystearate PH. EUR. 2002) are used.