Determination of microgram amounts of zirconium in geological materials by coprecipitation with iron(III) hydroxide and X-ray fluorescence spectrometry

Abstract

A method is described for the determination of microgram amounts of zirconium in complex matrices, based on the coprecipitation of zirconium with iron(III) hydroxide and the direct analysis of the precipitate by X-ray fluorescence spectrometry. The amount of iron in the digested sample is controlled by a solvent extraction step which precedes the formation of the precipitate. The method is free from interferences, takes advantage of the analysis of thin-film samples and has a detection limit of 0.9 µg g^–1 for a 10-s count; this is 20 times lower than that for the standard method of XRF analysis. The method has been applied to the analysis of a set of geological reference materials.