title: Spectrophotometric determination of calcium in zirconium powder by use of murexide.
abstract: An accurate spectrophotometric method is proposed for the determination of calcium in zirconium powder by use of murexide. A 0.4-g sample is dissolved in hydrofluoric and sulphuric acids, the solution evaporated to fumes of sulphuric acid, and a mercury cathode electrolysis made if more than 0.05% copper or nickel is present. Ammoniacal precipitation in the presence of ammonium chloride separates zirconium and other elements and an aliquot of filtrate is collected, equivalent to 0.2 g of sample. The ammonium salts are destroyed with nitric and hydrochloric acids and the calcium is determined with murexide. The high reagent blank is shown to be due to the reagent grade nitric acid, hydrochloric acid, and ammonium hydroxide.
authors.affiliation: Frankford Arsenal, Philadelphia, Pa. 19137, U.S.A.
authors.forename: H
authors.initials: H
authors.lastname: Gordon
authors.forename: G
authors.initials: G
authors.lastname: Norwitz