title: Determination of titanium in high-purity molybdenum and tungsten metals with diantipyrylmethane after separation by extraction of its cupferron complex.
abstract: A method for determining 0.0005-0.10% of titanium in high-purity molybdenum and tungsten metals is described. After sample dissolution, titanium is separated from the matrix materials by chloroform extraction of its cupferronate from an alkaline (pH 8) tartrate-EDTA medium, then determined spectrophotometrically with diantipyrylmethane at 390 nm. Interference from manganese during extraction is eliminated with sodium sulphite. Iron, zirconium, thorium, tin, aluminium and antimony are partially extracted under the proposed conditions, but moderate amounts of these elements may be present in the sample solution without causing error in the results. Interference from iron(III) during colour development is eliminated with ascorbic acid. Other impurities in the two high-purity metals described do not interfere in the proposed method.
authors.affiliation: Mineral Sciences Division, Mines Branch, Department of Energy, Mines and Resources, 555 Booth Street, Ottawa 4, Ontario, Canada.
authors.forename: E M
authors.initials: EM
authors.lastname: Donaldson