A method for age dating of uranium mineral particles by double focusing magnetic sector inductively coupled mass spectrometry (FS-ICPMS) and thermal ionization mass spectrometry (TIMS) was presented. Pb/U ratio in uranium mineral particles was measured by FS-ICPMS without any chemical separation procedure. Pb isotope composition in uranium mineral particles was determined by TIMS associated with micro column anion exchange resin method. Due to simplified chemical procedure and minimum use of reagents, the full procedure blank was reduced to 230 pg Pb, leading to the successful age dating of uranium mineral particles with relative standard deviation less than 2%.
Implementing a quality control system according to the guidelines of ISO17025,requires the validation of methods as well as the estimation of measurements. In this study, the uncertainty of the determination of trace uranium by isotope dilution high resolution inductively coupled plasma mass spectrometry (ID-ICPMS) had been evaluated.This evaluation illustrated the contribution of uncertainty of the blend isotope ratios was large. So the accuracy of determination of the isotope ratios is the major factor for improving the accuracy of the method.
