title: Determination of rare-earth elements and yttrium in silicate rocks by sequential inductively-coupled plasma emission spectrometry.
abstract: An ICP-AES method for determination of rare-earth elements (REE) and yttrium at trace levels in silicate rocks is described. The method involves decomposition of the rock sample by heating with a mixture of hydrofluoric and perchloric acid, followed by precipitation of the REE and Y as oxalates, with calcium as carrier. The oxalate precipitate is ignited to the oxide, which is then dissolved in dilute nitric acid and the solution is used for ICP-AES measurements, with use of pure REE solutions as calibration standards. The method has been applied to the determination of REE in a number of standard reference materials and the results have been compared with the reported values. Three other silicate rock samples have also been analysed for REE and Y by this method.
authors.affiliation: Geological Survey of India, Central Chemical Laboratory, Calcutta 700016, India.
authors.forename: P
authors.initials: P
authors.lastname: Roychowdhury
authors.forename: N K
authors.initials: NK
authors.lastname: Roy
authors.forename: D K
authors.initials: DK
authors.lastname: Das
authors.forename: A K
authors.initials: AK
authors.lastname: Das