Certification of a New Series of Gravimetrically Prepared Synthetic Reference Materials for n(236U)/n(238U) Isotope Ratio Measurements

A new series of gravimetrically prepared synthetic isotope reference materials, the so-called IRMM-075 series, with n(236U)/n(238U) isotope ratios varying from 10-4 to 10-9 has been prepared and certified. This series is suited for calibration of n(236U)/n(238U) measurements made by various mass spectrometric techniques such as TIMS, ICPMS, AMS, RIMS. Natural uranium with low 236U isotope abundance and highly enriched 236U were both purified using well proven chemical methodology. Weighed amounts of the dilutions of 236U and weighed amounts of natural U were mixed to form this set of n(236U)/n(238U) mixtures. Verification of the mixtures IRMM-075/1-6 was performed by TIMS measurements. The results agreed well with the certified values obtained from the gravimetrical mixing calculations. The uncertainties of the calculated isotopic ratios are significantly lower compared to typical uncertainties from mass spectrometric techniques such as TIMS and ICPMS and in particular to AMS and RIMS. The methods for the preparation and mixing are described and the certification and verification procedures are reported.

RICHTER Stephan;  ALONSO-MUNOZ Adolfo;  AREGBE Yetunde;  EYKENS Roger;  JAKOBSSON Ulf;  KEHOE Frances;  KUEHN Heinz;  VERBRUGGEN Andre;  WELLUM Roger; 

2010-03-29

ELSEVIER SCIENCE BV

JRC45906

0168-583X,   

https://publications.jrc.ec.europa.eu/repository/handle/JRC45906,   

10.1016/j.nimb.2009.10.073,