Determination of the iodine value of oils and fats: summary of collaborative study.

Two collaborative studies were conducted using the Wijs method for determining the iodine value in a wide range of vegetable and animal oils and fats. The results obtained when using carbon tetrachloride were compared to those obtained when using a substitute solvent mixture of cyclohexane and glacial acetic acid. The values reported for the iodine values indicate that the cyclohexane and acetic acid mixture can be used in place of carbon tetrachloride without loss of precision. The method has been adopted first action by AOAC INTERNATIONAL as an IUPAC/AOCS/AOAC method.