Donaldson E M
Mineral Sciences Division, Mines Branch, Department of Energy, Mines and Resources, Ottawa, Canada.
Talanta. 1970 Jul;17(7):583-91. doi: 10.1016/0039-9140(70)80006-6.
A method for determining up to 0.15% of vanadium in high-purity niobium and tantalum metals, cast iron, steel, non-ferrous alloys and silicates is described. The proposed method is based on the extraction of a red vanadium(V)-N-benzoyl-N-phenylhydroxylamine complex into chloroform from a sulphuric-hydrofluoric acid medium containing excess of ammonium persulphate as oxidant. The molar absorptivity of the complex is 428 l.mole(-1).mm(-5) at 475 nm, the wavelength of maximum absorption. Interference from chromium(VI) and cerium(IV) is eliminated by reduction with iron(II). Common ions, including large amounts of titanium, zirconium, molybdenum and tungsten, do not interfere.
本文描述了一种测定高纯度铌、钽金属、铸铁、钢、有色金属合金和硅酸盐中钒含量达0.15%的方法。该方法基于在含有过量过硫酸铵作为氧化剂的硫酸 - 氢氟酸介质中，将红色的钒（V）-N-苯甲酰基-N-苯基羟胺络合物萃取到氯仿中。该络合物在最大吸收波长475nm处的摩尔吸光系数为428 l·mol⁻¹·mm⁻¹。通过用铁（II）还原消除铬（VI）和铈（IV）的干扰。常见离子，包括大量的钛、锆、钼和钨，不产生干扰。
