A new study describes a rapid and accurate method for isotopic analysis of uranium, plutonium, and americium in post-detonation debris simulants using resonance ionization mass spectrometry (RIMS), which could be a valuable tool in nuclear forensics.
A team of researchers led by Michael R. Savina from the Lawrence Livermore National Laboratory has developed a method to rapidly analyze the isotopic compositions of uranium (U), plutonium (Pu), and americium (Am) in post-detonation debris samples. Their findings have been published in the Journal of Analytical Atomic Spectrometry (1).
The researchers demonstrated their technique on solid basalt matrices spiked with trace amounts of uranium, plutonium, and americium to mimic post-detonation debris. They were able to accurately analyze materials containing parts-per-million (ppm) to parts-per-billion (ppb) levels of actinides without separating them from the host matrix, using less than 100 nanograms of sample material. The measured isotopic compositions of U, Pu, and Am were accurate to within 10%, except for the 238Pu isotope, which was compromised by low concentration and excesses of 238U up to 34,000:1.
To accurately measure the 238Pu/239Pu ratio in the sample, the team developed a new method called “blinking” that takes advantage of the unique ability of resonance ionization mass spectrometry (RIMS) to rapidly and accurately quantify the backgrounds from all sources. The method was successfully used to measure the 238Pu/239Pu ratio on a sample containing 1.4 × 106 atoms of 238Pu at a concentration of 0.1 ppb in the host material.
RIMS is a highly sensitive analytical technique used for the detection and quantification of trace elements and isotopes. It uses laser light to ionize atoms or molecules of interest, leading to their separation and detection based on their mass-to-charge (m/z) ratio. RIMS can detect extremely low concentrations of isotopes, making it useful for applications in environmental monitoring, nuclear forensics, and isotopic analysis in geology and cosmology. RIMS can also be coupled with other mass spectrometry techniques, such as time-of-flight and quadrupole mass spectrometry, to enhance its sensitivity and selectivity.
Although traditional mass spectrometry is currently the most accurate and precise method for determining actinide isotopic compositions, it typically requires time-consuming dissolution and chemical purification prior to analysis. However, RIMS has been used to measure isotope ratios in mixed actinide samples without chemical purification. It has also demonstrated the ability to measure 241Pu and 238Pu in both pure standard materials and spent nuclear fuel, including spent fuel particles from the Chernobyl Exclusion Zone that have significant environmental exposure.
This work represents an important step forward in the rapid analysis of post-detonation debris samples, where the actinides are present as trace elements in an environmental matrix and the 238U/238Pu is significantly higher than 4000. The team's RIMS method offers a promising alternative to the traditional methods of isotope analysis, which are time-consuming and require significant amounts of sample preparation.
(1) Savina, M. R.; Shulaker, D. Z.; Isselhardt, B. H.; Brennecka, G. A. Rapid isotopic analysis of uranium, plutonium, and americium in post-detonation debris simulants by RIMS. J. Anal. At. Spectrom. 2023, ASAP. DOI:10.1039/D3JA00096F
Getting accurate IR spectra on monolayer of molecules
April 18th 2024Creating uniform and repeatable monolayers is incredibly important for both scientific pursuits as well as the manufacturing of products in semiconductor, biotechnology, and. other industries. However, measuring monolayers and functionalized surfaces directly is. difficult, and many rely on a variety of characterization techniques that when used together can provide some degree of confidence. By combining non-contact atomic force microscopy (AFM) and IR spectroscopy, IR PiFM provides sensitive and accurate analysis of sub-monolayer of molecules without the concern of tip-sample cross contamination. Dr. Sung Park, Molecular Vista, joined Spectroscopy to provide insights on how IR PiFM can acquire IR signature of monolayer films due to its unique implementation.
Hot News on Agilent LDIR, New Developments, and Future Perspective
April 25th 2024Watch this video featuring Darren Robey and Dr. Wesam Alwan from Agilent Technologies to gain insights into the future trends shaping microplastics research and the challenges of their characterization. Discover the essential components necessary for accurate microplastics analysis and learn how the Agilent 8700 LDIR system addresses these challenges. Offering rapid and precise analysis capabilities, along with easy sample preparation methods that minimize contamination, the Agilent 8700 LDIR system is at the forefront of advancing microplastics research.
Researchers Develop Adaptive Gap-Tunable SERS Device
April 24th 2024In a new study, researchers from Ulsan National Institute of Science and Technology and Pohang University of Science and Technology presented a new surface-enhanced Raman spectroscopy (SERS) device, improving gap plasmon resonance.