Investigation on Absorbents and Identification of Impurity in Potassium Cyanide Used for the Determination of Chlorine in Air

Abstract

Several kinds of absorbents, which were used for the determination of chlorine in the air by the pyridine·pyrazolone method, were investigated. Among p-toluenesulfonamide, sulfamic acid, 5, 5-dimethylhydantoin, isocyanuric acid and succinimide, only p-toluenesulfonamide was useful for the absorbent ; the others were useless because of a consumption of chlorine, a slow formation velocity of cyanogen chloride or an instability of chlorine. Furthermore, most of commercial potassium cyanides, which were also used for the determination method, were found to contain a reducing impurity. The impurity was a sulfite ion, and its content ranged from 100μg to 1400μg per 1 g of each potassium cyanide tested.