Development of isotopic certified reference materials by metrological approach

摘要

In recent years, NIM carried out the study of highly sophisticated measurement methods for isotopes, and development of the reference materials of isotopes with the clear metrological traceability to SI units. Herein development of isotopic CRMs of some elements (cadmium and so on) with absolute isotope ratios are presented, including purification of enriched isotope materials, preparation of series synthetic isotopic mixtures, determination of enriched isotopic composition by means of the total evaporation TIMS, and a rigorous assessment of the measurement uncertainty.