title: Spectrophotometric determination of uranium(VI) by solvent extraction with trioctylphosphine oxide and a molten mixture of biphenyl and naphthalene.
abstract: Uranium in ores has been determined spectrophotometrically after extraction with trioctylphosphine oxide (TOPO) into a molten mixture of biphenyl and naphthalene. By addition of salting-out agents such as sodium nitrate to the aqueous phase and cooling, the organic phase can be obtained as a solid lump on the surface of the aqueous phase, making its collection simple. The uranium can then be determined directly in the organic phase with 1-(2-pyridylazo)-2-naphthol or 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol.
authors.affiliation: Department of Chemistry, Faculty of Science, Okayama University of Science, Ridai-cho, Okayama 700, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kojima
authors.forename: Y
authors.initials: Y
authors.lastname: Shigetomi