Study of the Tungsten Hydroquinone Color; Spectrophotometric Determination of Tungsten in Tungsten Steels

摘要

An investigation was made of the red color produced by tungsten and hydroquinone in a concentrated sulfuric acid medium. Various factors affecting the color were studied including the effect of phosphoric acid, water, hydrochloric acid, stannous chloride, and wave length at which the color is measured. The interference from iron, molybdenum, vanadium, and titanium was studied. A method is described for the determination of tungsten in tungsten steels that involves precipitation of the tungsten with cinchonine, ignition to tungstic oxide, dissolution of the tungstic oxide in sodium hydroxide, and development of the tungsten hydroquinone color on an aliquot of the solution. (Author)