Analytical techniques capable of determining the spatial distribution and quantity (mass and/or particle number) of engineered nanomaterials in organisms are essential for characterizing nano-bio interactions and for nanomaterial risk assessments. Here, we combine the use of dynamic secondary ion mass spectrometry (dynamic SIMS) and single particle inductively coupled mass spectrometry (spICP-MS) techniques to determine the biodistribution and quantity of gold nanoparticles (AuNPs) ingested by Caenorhabditis elegans. We report the application of SIMS in image depth profiling mode for visualizing, identifying, and characterizing the biodistribution of AuNPs ingested by nematodes in both the lateral and z (depth) dimensions. In parallel, conventional- and sp-ICP-MS quantified the mean number of AuNPs within the nematode, ranging from 2 to 36 NPs depending on the size of AuNP. The complementary data from both SIMS image depth profiling and spICP-MS provides a complete view of the uptake, translocation, and size distribution of ingested NPs within Caenorhabditis elegans.

Rare earth elements such as neodymium and samarium are ideal for probing the neutron environment that spent nuclear fuels are exposed to in nuclear reactors. The large number of stable isotopes can provide distinct isotopic signatures for differentiating the source material for nuclear forensic investigations. The rare-earth elements were isolated from the high activity fuel matrix via ion exchange chromatography in a shielded cell. The individual elements were then separated using cation exchange chromatography. The neodymium and samarium aliquots were analyzed via MC–ICP–MS, resulting in isotopic compositions with a precision of 0.01–0.3%.

Secondary ion mass spectrometry (SIMS) plays an important role in nuclear forensics through its ability to identify isotopic ratios of particles accurately and precisely from samples obtained by inspectors [Boulyga et al., J. Anal. At. Spectrom. 30, 1469 (2015)]. As the particle mass can be on the order of subpicograms, it is important to maximize the sample utilization efficiency of U+ to make high-quality isotopic measurements. The influence of primary ion beam species and polarity on U+ sample utilization efficiency has been previously investigated by Ranebo et al. [J. Anal. At. Spectrom. 24, 277 (2009)]. However, the effect of sample substrate on uranium ion production efficiency and sputtering profile has not been investigated. This work will explore those influences on sample utilization efficiency by analyzing monodisperse uranium oxide microspheres deposited onto graphite and silicon planchets. The particles were mapped using an automated scanning electron microscope, and their coordinates were converted to the SIMS coordinate system using fiducial marks. Results indicate higher U+ sample utilization efficiencies when sputtering with O− and O2− on graphite planchets compared with O2+, whereas O2− gave higher U+ sample utilization efficiencies with silicon wafers compared to O− and O2+. Additionally, during sputtering of uranium particles on silicon wafers with O− and O2−, a sudden drop in U+ signal intensity was observed, which was not present during sputtering with O2+ or any primary ion species for particles on graphite. This drop in U+ signal intensity occurred simultaneously with an increase in UO+ and UO2+ signals, indicating a change in the local matrix around the uranium particle that is unique to silicon compared to graphite.

Analysis of post-nuclear detonation materials provides information on the type of device and its origin. Compositional analysis of trinitite glass, fused silicate material produced from the above ground plasma during the detonation of the Trinity nuclear bomb, reveals gross scale chemical and isotopic heterogeneities indicative of limited convective re-homogenization during accumulation into a melt pool at ground zero. Regions rich in weapons grade Pu have also been identified on the surface of the trinitite sample. The absolute and relative abundances of the lanthanoids in the glass are comparable to that of average upper crust composition, whereas the isotopic abundances of key lanthanoids are distinctly non-normal. The trinitite glass has a non-normal Nd isotope composition, with deviations of −1.75 ± 0.60 ε (differences in parts in 104) in 142Nd/144Nd, +2.24 ± 0.75 ε in 145Nd/144Nd, and +1.01 ± 0.38 ε in 148Nd/144Nd (all errors cited at 2σ) relative to reference materials: BHVO-2 and Nd-Ames metal. Greater isotopic deviations are found in Gd, with enrichments of +4 ± 1 ε in 155Gd/160Gd, +4.19 ± 0.75 ε in 156Gd/160Gd, and +3.48 ± 0.52 ε in 158Gd/160Gd compared to BHVO-2. The isotopic deviations are consistent with a 239Pu based fission device with additional 235U fission contribution and a thermal neutron fluence between 1.4 and 0.97 × 1015 neutrons/cm2.