Spectrophotometric determination of sulphate in propellents and nitrocellulose

Abstract

An accurate method is proposed for the determination of sulphate in propellents and nitrocellulose that requires only 45 minutes to carry out. The sample is treated with a mixture of nitric acid, perchloric acid and magnesium nitrate, and the solution is evaporated to dryness over a bunsen burner. The salts deposited are heated for 5 minutes with a mixture of hydriodic, hypophosphorous and hydrochloric acids in a simplified distillation apparatus, with nitrogen passing through the system; the hydrogen sulphide that results from the reduction of the sulphate is absorbed into ammonia solution, lead citrate is added, and the brownish yellow lead sulphide colour is measured.