The determination of iodine in large samples of foodstuffs

Abstract

The method of Kendall was found satisfactory for estimating small amounts of iodine as low as 0.02 mg. where destruction of large amounts of organic matter was not involved. If, however, the size of the sample is increased there is a corresponding decrease in accuracy. In order to reduce the bulk of material the following processes were carried out: Cereal grains were made into beer without removal of any solid matter and the alcohol volatilized after making the beer alkaline. In the combustion, the fumes were passed through an alkaline solution to catch the iodine. After the iodine was in the form of I₂ it was shaken out with carbon tetrachloride and then this carbon tetrachloride shaken with a dilute solution of SO₂ to get the iodine into water solution again as iodine. By these processes both organic and inorganic inert constituents may be eliminated.