Determinationof1ppmIronPhosphorusinUltraPure.PDFVIP

Application Note Metallurgy ICP-OES ICP47 Determination of 1 ppm Iron and Phosphorus in Ultra Pure Copper Dr. Rainer Nehm, HORIBA Scientific, Unterhaching, Germany A round robin was held under the direction of the German Federal Institute for Materials Research and Testing, BAM (Bundesanstalt für Materialforschung und prüfung), as part of the development of three new Cu reference materials (BAM-M390, BAM-M391 and BAM-M392) with very low mass fractions of Fe, P and Sn. Several members of the German GDMB Working Group for Copper, who are able to analyze Fe, P and Sn at very low concentrations in the solid (Fe: 1 ppm, P: 1 ppm to 6 ppm and Sn: 0.1 ppm) participated in this round robin. Several analytical techniques were used for the analysis: ? Photometry (colorimetric method) ? ICP-OES ? ICP-OES after Lanthanum precipitation ? ICP-MS ? GD-MS As the photometric method and the ICP-OES method after Lanthanum precipitation are time consuming methods and as Mass Spectrometry techniques are more expensive and sometimes increase the uncertainty and the time for sample preparation due to dilutions, ICP-OES remains as the most interesting technique due to its ease of use. The high resolution of the HORIBA Scientific ULTIMA 2 ICP-OES Spectrometer allows analyzing these samples directly after dissolution without any special sample treatment or dilution. Due to the very low concentration of Sn ( 0.1 ppm) it was decided not to try to analyze it. The analysis may be possible with an increased initial sample weight or with the use of a hydride generation system. Several issues arise for the analysis of such high purity materials. Careful cleaning of flasks and all spare parts like on the caps for a hot plate the flasks with a is required. For mthixetusreamopf lHeCpl raenpdarHat2ioOn2 procedure, ultra pure nitric acid has to be used to avoid any contamination of the samples. Some issues that are directly related to the development of new CRM materials remain. To perform th