title: Determination of platinum, palladium, and rhodium in automotive catalysts using high-energy secondary target X-ray fluorescence spectrometry.
abstract: A fast and direct determination procedure for precious metals in spent automotive catalyst was developed using the novel high-energy polarized-beam XRF. A sample preparation method working directly on the ground material was optimized. The material was pressed as a pellet using wax as a binder; no internal standard was added. The standards for this application were available spent automotive catalyst, previously analyzed by ICP-OES to verify their concentration, prepared in the same way as the unknown samples. The investigated concentration ranged from nearly 0 to approximately 2700 ppm for Pt, to 500 ppm for Rh, and to 7500 ppm for Pd. The repeatability of the XRF measurement appeared to be better than 0.5%, while the precision of the whole method was approximately 1%. The accuracy of the XRF method was verified with the well-established (but very time-consuming) ICP-OES method; a good agreement (no difference when using the 95% confidence interval) was found for the results. When using an irradiation time of 500 s for the CsI secondary target and the Zr secondary target, the detection limits for Pt, Pd, and Rh were found to be better than 5 ppm.
authors.affiliation: Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerpen, Belgium. katleen.vanmeel@ua.ac.be
authors.forename: Katleen
authors.initials: K
authors.lastname: Van Meel
authors.forename: Anne
authors.initials: A
authors.lastname: Smekens
authors.forename: Marc
authors.initials: M
authors.lastname: Behets
authors.forename: Paul
authors.initials: P
authors.lastname: Kazandjian
authors.forename: René
authors.initials: R
authors.lastname: Van Grieken