A new technique for microdetermination of sulphur compounds by the iodine-azide reaction in aqueous and aqueous-organic media with a modified Coleman nitrogen analyser

Abstract

A new catalytic method for the determination of certain types of organic and inorganic sulphur compounds is described. The method is based on the induced reaction of sodium azide with iodine, the nitrogen liberated in the reaction being measured with a modified Coleman nitrogen analyser. The modification consists of shortening the operating cycle by disconnection of the furnaces, and including a reactor in the flow system. The sulphur compounds are analysed in aqueous or aqueous-organic media. Na2S, sodium tetramethylenedithiocarbamate and thiourea have been determined in the ranges 1–200, 0.5–100 and 2–200μg respectively. The most important advantages of the proposed method are its simplicity and accuracy, and the possibility of carrying out the determination in turbid and heterogeneous mixtures.