Production of (236)~Np and (236)~Pu for Isotope Dilution Mass Spectrometry

摘要

Isotope dilution mass spectrometry (IDMS) methods including thermal ionization mass spectrometry (TIMS) and multi-collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) are currently the most sensitive methods for measuring actinide traces in environmental samples. For accurate quantitative results, an isotope dilution tracer is added to each sample and the ratio of the ana-lyte to the tracer is used to calculate its amount in a given sample. An ideal IDMS tracer is a stable or long-lived isotope that is not found in the sample. Examples include (244)~Pu for plutonium, (233)~U for uranium and (229)~Th for thorium measurements.