A silver chloride/sulphide amplification reaction for the microdetermination of chloride ion

Abstract

An amplification procedure is described for the determination of 0.05–10 mg amounts of chloride ion. The amplification procedure is an arithmetic one based on precipitation of silver chloride, metathesis with sodium sulphide to silver sulphide and sodium chloride, followed by reprecipitation of the chloride, etc. The final yield of Ag2S is converted into AgCl for weighing. In this way, precipitates of silver chloride which are too small to be used for gravimetric purposes can be amplified to produce weighable amounts of silver chloride. The method is precise and gives accurate results in comparison with other methods at low concentrations. The process may also be automated.