Samples are decomposed with hydrofluoric acid and perchloric acid in the presence of W181 tracer. Molybdenum is extracted from a hydrochloric acid solution with tributyl phosphate. Tungsten is separated from most other elements by extraction of the a-benzoinoximate into chloroform. Stannous chloride in concentrated hydrochloric acid is used to strip tungsten and reduce it to W+5 . The amount of tungsten is determined spectrophotometrically after extraction as the thiocyanate complex into amyl alcohol. The correction for chemical losses is determined by counting W181.
|Title||Spectrophotometric determination of tungsten in rocks by an isotope dilution procedure|
|Authors||E.G. Lillie, L. Paul Greenland|
|Publication Subtype||Journal Article|
|Series Title||Journal of Research of the U.S. Geological Survey|
|Record Source||USGS Publications Warehouse|