HR: 09:01h
AN: V41E-05    [Abstracts]
TI: Preparation and Application of new Synthetic Uranium Isotopic Reference Materials at IRMM
AU: * Richter, S
EM: stephan.richter@ec.europa.eu
AF: IRMM-JRC-EU, Retieseweg 111, Geel, 2440, Belgium
AU: Alonso-Munoz, A
EM: adolfo.alonso-munoz@ec.europa.eu
AF: IRMM-JRC-EU, Retieseweg 111, Geel, 2440, Belgium
AU: Eykens, R
EM: roger.eykens@ec.europa.eu
AF: IRMM-JRC-EU, Retieseweg 111, Geel, 2440, Belgium
AU: Kuehn, H
EM: heinz.kuehn@ec.europa.eu
AF: IRMM-JRC-EU, Retieseweg 111, Geel, 2440, Belgium
AU: Verbruggen, A
EM: andre.verbruggen@ec.europa.eu
AF: IRMM-JRC-EU, Retieseweg 111, Geel, 2440, Belgium
AU: Wellum, R
EM: roger.wellum@gmail.com
AF: IRMM-JRC-EU, Retieseweg 111, Geel, 2440, Belgium
AU: Aregbe, Y
EM: yetunde.aregbe@ec.europa.eu
AF: IRMM-JRC-EU, Retieseweg 111, Geel, 2440, Belgium
AB: Several new sets of synthetic isotope reference materials for mass spectrometer calibration have been developed at IRMM based on proven methods of purifying and mixing highly enriched oxides. In the first stage a set of 10 mixtures of 233U, 235U and 238U was made in which the 235U:238U ratios were kept at 1:1 and the 233U/235U ratios varied from 1.0 to 10-6 (IRMM-074). This set is ideal for checking the linearity response of detectors used in isotope mass spectrometry. For an absolute calibration of 235U/238U ratio measurements two types of synthetic mixtures were prepared. First the IRMM-3020-3090 set of primary isotopic mixes with 20%,35%, 50%, 75% and 90% 235U enrichment was made. Secondly also a double spike IRMM-3636 with a 233U/236U ratio of 1:1 was prepared which allows internal mass fractionation correction for 235U/238U ratio measurements. The 234U abundance of this double spike material is low enough to allow an accurate and precise correction, even within measurements of close to equilibrium uranium samples. For all synthetic isotope mixtures certification is done based on weights, purity and isotopic enrichment of the highly enriched starting materials. However, a careful verification e.g. by mass spectrometry is necessary. This paper describes the preparation techniques, verification measurements using TIMS and some applications for synthetic isotope reference materials produced by IRMM.
DE: 1000 GEOCHEMISTRY
DE: 1094 Instruments and techniques
DE: 1120 Isotopic disequilibrium dating
DE: 1194 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting