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 (Thermal Ionization Mass Spectrometry), ICPMS (Inductively Coupled Plasma Mass Spectrometry), AMS (Accelerator Mass Spectrometry) and RIMS (Resonance Ionization Mass Spectrometry).