2014 年 21 巻 1 号 p. 65-70
Air-exposed di(2-ethylhexyl) dithiophosphate (Phoslex DT-8®) has been previously shown to be able to selectively extract scandium ions from waste water produced during zirconium refining. In the absence of exposure to air, Phoslex DT-8® is not effective for scandium ion extraction, therefore, a compound produced by air-oxidation was suspected to be responsible for the selective extraction of the metal. In the present study, we employed 31P NMR spectroscopy and mass spectrometry in order to identify this active species. We revealed that a sulfur atom of Phoslex DT-8® was substituted for an oxygen atom on oxidation yielding O,O-bis(2-ethylhexyl) hydrogen thiophosphate (BOHTP). This compound was subsequently synthesized in high purity, and was confirmed to possess similar extraction capabilities for scandium as the oxidized Phoslex DT-8®.