Determination of iodine values using 1,3-dibromo-5,5-dimethylhydantoin (DBH) and ethyl acetate as solvent. Analytical methods with DBH in respect to environmental and economical concern, part 18.

Iodine values (iodine numbers) of several fixed oils and lard can be determined in ethyl acetate, an easily biodegredable solvent, instead of chloroform according to PH. EUR. 2002. Iodine monobromide has been replaced by 1,3-dibromo-5,5-dimethylhydantoin (DBH) and potassium iodide (KI) and the reaction time was reduced to 5 min only. However, cod-liver oil and linseed oil require a reaction time of 30 min and a smaller weight of sample. Longer reaction times are also necessary for soya oil and wheat germ oil. Iodine values of linseed oil determined according to method A of PH. EUR. 2002, are dependent on the amount of sample, even in the range prescribed by the pharmacopoeia.