Potentiometric determination of iodine in pharmaceutical preparations

Methods for the determination of organically bound iodine were compared. A preliminary destruction of the sample was preferable. The sample was mineralized using the Schöniger combustion. Since direct potentiometry of the iodide ion was used, further reduction of the sample was necessary. Several reductors were compared, and the best results were obtained with Devarda alloy. The proposed method was amployed for the determination of iodine in X-ray contrast products. Pure compounds and pharmaceutical preparations were investigated. The coefficient of variation of the method was 0.9%.