The Great Scientific Exchange (SciX), Palm Springs, CA, October 13-18, 2019
Sergei Tolmachev was a coauthor on a poster presentation at the SciX conference in October 2019.
Determination of U, Pu, and Am in human keratinous samples using extraction chromatography and ICP-MS
Dana L. Wegge (University of Missouri), Sergei Y. Tolmachev (USTUR), John D. Brockman (University of Missouri Research Reactor)
Human biomonitoring at nuclear facilities is a potential tool for treaty compliance monitoring. A non-invasive bioassay sensitive to special nuclear materials could be useful for identifying personnel involved in clandestine activities. A recent, small pilot study has demonstrated that hair and nail samples collected from occupationally exposed contain actinides. A limitation of the pilot study is that occupational exposure was self-reported and information was not available on how or when workers were exposed to actinides. To further develop the use of keratinous material as a biomointor for exposure to internally deposited actinides, hair and nail samples from the United States Transuranium and Uranium Registries (USTUR) will be analyzed for Pu, Am, and U. The advantage of this cohort is that worker exposure histories are well documented and actinide concentrations in hair and nail can be related to concentrations in other organs. The hair and nail samples from the USTUR have previously been acid-digested and stored in 6–8 M HCl. This work will compare two methods developed to measure Pu, Am, and U isotope ratios in keratinous samples stored in 6-8 M HCl. In the first method, samples are evaporated to dryness and brought back up in 3 M HNO3. The separation is accomplished using TEVA, UTEVA, and DGA resin cartridges. In the second method, the samples are evaporated to dryness and brought back up in 6 M HCl. The separation is accomplished using a single DGA resin. The separated samples are analyzed for 235U/238U and 236U/238U using a multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) with a desolvating nebulizer (DSN). The DSN-MC-ICP-MS also used to analyze 239Pu, 240Pu, and 241Am by isotope dilution techniques. Each method will be evaluated by sample limit of detection, chemical tracer recovery, and analysis of duplicate samples. [USTUR-0527-19A]