title: Polarographic determination of trace amounts of thorium.
abstract: A sensitive linear-sweep polarographic method for the determination of thorium is described. It is based on the thorium complex with Xylidyl Blue I (XBI) in a medium containing ethylenediamine, 1,10-phenanthroline, oxalic acid and ninhydrin, at pH 10.5-11.5. The complex has been proved to be Th(XBI)(2), with log beta' = 9.6. The method can be used to determine trace amounts of thorium over the range 3.5 x 10(-8)-3 x 10(-6)M. The detection limit is 1 x 10(-8)M. A solvent extraction procedure is necessary to eliminate interference from several cations. The method has been applied to determination of traces of thorium in minerals, with good results.
authors.affiliation: Department of Chemistry, University of Wuhan, Wuhan, People's Republic of China.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhao
authors.forename: X
authors.initials: X
authors.lastname: Cai
authors.forename: P
authors.initials: P
authors.lastname: Li
authors.forename: H
authors.initials: H
authors.lastname: Yang