Spectrophotometric Determination of Sulfate in Chrome Plating Baths.

摘要

An accurate,rapid spectrophotometric method is described for the determination of sulfate in chrome plating baths. An aliquot of the bath is treated with a mixture of hydriodic,hypophosphorous,and hydrochloric acids in a special distillation apparatus while passing nitrogen through the system. The hydrogen sulfide which results from the reduction of the sulfate is absorbed into ammonium hydroxide,lead citrate is added,and the yellowish-brown lead sulfide color is measured. (Author)