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Two ICP-MS methods were developed to measure the radiotoxic isotope 226Ra in brain tissues from a radium dial painter worker. The first method was a direct analysis of acid digested samples using quadrupole ICP-MS. The instrumental LOD of 226Ra was 0.1 ng kg−1. Polyatomic interferences at m/z 226 were investigated and Pb was identified from a polyatomic interferent in an in-house sample prepared from bovine brain, with a 226/208 formation ratio of 4 × 10−8. The quadrupole ICP-MS method was also used to measure levels of beryllium, strontium, and uranium. A second method was developed that included cation-exchange chromatography to separate 226Ra followed by analysis with sector field MC-ICP-MS. The instrumental LOD for the cation exchange method with MC-ICP-MS detection was 0.5 pg kg−1 (19 mBq kg−1). The measured concentrations of 226Ra in different brain regions ranged from 0.09–0.72 ng kg−1 (3.3–27 Bq kg−1) and radium was non-uniformly distributed in the brain. [ABSTRACT FROM AUTHOR]

In January 2006 the beryllium reflector and graphite wedge that contained the k0 INAA irradiation position were replaced at the University of Missouri Research Reactor. Prior to replacement the average values of the flux ratio, f, and the epithermal non-ideality factor, α, were 57.4 ± 4.5 and 0.039 ± 0.012. The values of f and α immediately after the beryllium and graphite wedge replacement were 39.4 ± 0.6 and 0.021 ± 0.002. Subsequent measurements indicate that the neutron spectrum hardened with time, possibly due to the buildup of the 6Li atom density to saturation. [ABSTRACT FROM AUTHOR]

A bioassay capable of monitoring occupational or environmental exposure to special nuclear materials would be a useful tool for nuclear nonproliferation programs. Hair and nail are potential biomonitors of exposure to U and Pu. A method is described to measure isotope ratios of ultra-trace concentrations of U and Pu in hair and nail samples. The method uses multiple extraction chromatography resins to separate U and Pu fractions from the sample matrix. The U recovery was quantitative while the Pu recovery ranged from 81% to 109%, with a U decontamination factor of 5 x 104. Following the separation 234U/238U, 235U/238U and 240Pu/239Pu were measured in human hair and hair and nail samples using multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS). The human hair and nail samples had elevated ratios of 234U/238U which could reflect exposure to naturally fractionated U. [ABSTRACT FROM AUTHOR]

The 239 Pu, 238 U, and 241 Am concentrations and 239 Pu/ 240 Pu, 235 U/ 238 U, and 236 U/ 238 U atom ratios were measured in the hair and nail samples using a new method utilized TEVA, UTEVA, and DGA extraction chromatography and multi-collector ICP-MS. Samples were collected from individuals who donated their bodies to the United States Transuranium and Uranium Registries. The concentration of 239 Pu ranged from 0.22 to 15.8 ng/kg. The 240 Pu/ 239 Pu isotopic ratios ranged from 0.026 to 0.127 which is consistent with weapons-grade plutonium. Concentration of uranium fell between 1.84 μg/kg and 29.5 μg/kg and 235 U/ 238 U ratios ranged from 4.8 × 10 -3 to 7.6 × 10 -3 . Elevated 236 U/ 238 U atom ratios were measured in two cases and ranged from 5.0 × 10 -6 - 2.4 × 10 -5 indicating exposure to spent or reprocessed uranium material. The concentration of 241 Am was measured in four hair samples and ranged from 0.02 to 0.21 ng/kg., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:John D. Brockman reports was provided by University of Missouri. John D. Brockman reports a relationship with University of Missouri that includes: employment., (Copyright © 2023. Published by Elsevier B.V.)

Prompt analysis of fission products and rare earth elements (REE)s in post-detonation nuclear debris is critical for nuclear forensic analysis. In this work the compatibility of ammonium biflouoride fusion and microwave digestion in combination with high pressure ion chromatography (HPIC) separation was examined for the analysis of REEs. The refractory geological materials USGS G-2, QLO-1a, AGV-2 and BHVO-2 were used as surrogate post-detonation debris. The HPIC separation used a mixed bed ion exchange column with a gradient elution consisting of oxalic acid and diglycolic acid mobile phases. Quantitative recovery for seven REEs was achieved using the in-line HPIC-ICP-MS. An off-line HPIC method was also developed to separate U, Pu, and REE fission products. Collected fractions were analyzed by ICP-MS or gamma ray spectroscopy. The offline HPIC separation with detection of short-lived fission products with gamma ray spectroscopy had detection limits 5-20,000 times lower than quadrupole ICP-MS for stable REEs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

High-temperature ammonium bifluoride (ABF) fusions were evaluated for potential use in rapid dissolution of post-detonation nuclear debris. The ABF fusion was carried out in a Pt crucible which allowed evaluation of higher fusion and evaporation temperatures. The high-temperature ABF fusion dissolution method was evaluated using geological reference materials: USGS QLO-1a Quartz Latite, USGS SDC-1 Mica Schist, and NIST 278 Obsidian Rock. The optimized dissolution method involved a 10 min fusion at 540 °C, a 5 min reflux in 8 M HNO 3, an evaporation at 300 °C and final dilution into 45 mL of 2% (v/v) HNO 3 . The final solution was filtered after heating at 105 °C using a hotblock. This dissolution method was simple, requiring only a hotplate or hotblock, filtered samples were available for ICP-MS analysis or radiochemical separation within 150 min, and was found to have high (>90%) recovery for many isotopes of interest in nuclear forensics applications. U and Pu in the dissolved material was separated using TEVA and UTEVA extraction chromatography columns, a process which resulted in >90% recovery. An irradiated U tracer was spiked into the material prior to dissolution and analyzed for recovery of major fission products and 239 Np. The monitored radionuclides had recoveries of greater than 90%, except for the volatile radioiodine isotopes., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The speciation analysis of As in urine samples can provide important information for epidemiological studies. Considering that these studies involve hundreds or thousands of samples, a fast and reliable method using a simple LC system with short-length mixed bed ion exchange chromatographic column coupled to ICP-MS for As speciation in human urine samples was developed in this work. Separation of AB+TMAO, DMA, AC, MMA and As III +As V was accomplished within 5min with good resolution when ammonium carbonate solutions were used as mobile phases and H 2 O 2 was added to samples to quantitatively convert As III -As V . Repeatability studies yielded RSD values from 2.0% to 4.8% for all species evaluated. Limits of detection (LOD) for As species ranged from 0.003 to 0.051ngg -1 . Application of the method to human urine samples from a non-contaminated area showed that the sum of species measured corresponded to 62-125% of the total As in the sample. The recovery values for these species in urine SRM 2669 were in the range of 89-112% and demonstrated the suitability of the proposed method for epidemiological studies., (Copyright © 2016 Elsevier B.V. All rights reserved.)

k(0) Instrumental Neutron Activation Analysis (k(0) INAA) was evaluated at the University of Missouri Research Reactor (MURR). The MURR, unlike many other research reactors that employ k(0) INAA, is refueled on a weekly basis. To determine if the neutron spectrum is stable enough for routine k(0) INAA analysis, the neutron spectrum parameters alpha and f were measured over a 9 month period. The average values of f and alpha measured using the Cd ratio multi monitor technique were 57.4+/-4.5 and 0.039+/-0.012, respectively. It was determined that k(0) INAA could be used at the MURR by employing the average value of alpha and f. However, significant measurement bias could occur for elements with high Q(0) values if the true spectral parameters deviate by more than 10% from the average value.