Determination of oxidic impurities in some lead halides

The paper presents a method for the determination of the concentration of oxidic compounds — ranging between 0.16 and 4.0 wt.% PbO — in some lead halides (except iodide). The method is based on the reaction of oxidic compounds with sulphur in sealed evacuated glass ampoules at 440°C under formation of sulphur dioxide. The SO2 produced can be determined by both iodometric titration and photometric measurement. The latter method gives more satisfactory and reproducible results.