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Background: BCL‐2 inhibition through venetoclax (VEN) targets acute myeloid leukemia (AML) blast cells and leukemic stem cells (LSCs). Although VEN-containing regimens yield 60–70% clinical response rates, the vast majority of patients inevitably suffer disease relapse, likely because of the persistence of drug-resistant LSCs. We previously reported preclinical activity of the ribonucleoside analog 8-chloro-adenosine (8-Cl-Ado) against AML blast cells and LSCs. Moreover, our ongoing phase I clinical trial of 8-Cl-Ado in patients with refractory/relapsed AML demonstrates encouraging clinical benefit. Of note, LSCs uniquely depend on amino acid-driven and/or fatty acid oxidation (FAO)-driven oxidative phosphorylation (OXPHOS) for survival. VEN inhibits OXPHOS in LSCs, which eventually may escape the antileukemic activity of this drug. FAO is activated in LSCs isolated from patients with relapsed AML. Methods: Using AML cell lines and LSC-enriched blast cells from pre-treatment AML patients, we evaluated the effects of 8-Cl-Ado, VEN and the 8-Cl-Ado/VEN combination on fatty acid metabolism, glycolysis and OXPHOS using liquid scintillation counting, a Seahorse XF Analyzer and gene set enrichment analysis (GSEA). Western blotting was used to validate results from GSEA. HPLC was used to measure intracellular accumulation of 8-Cl-ATP, the cytotoxic metabolite of 8-Cl-Ado. To quantify drug synergy, we created combination index plots using CompuSyn software. The log-rank Kaplan–Meier survival test was used to compare the survival distributions of the different treatment groups in a xenograft mouse model of AML. Results: We here report that VEN and 8-Cl-Ado synergistically inhibited in vitro growth of AML cells. Furthermore, immunodeficient mice engrafted with MV4-11-Luc AML cells and treated with the combination of VEN plus 8-Cl-Ado had a significantly longer survival than mice treated with either drugs alone (p ≤ 0.006). We show here that 8-Cl-Ado in the LSC-enriched population suppressed FAO by downregulating gene expression of proteins involved in this pathway and significantly inhibited the oxygen consumption rate (OCR), an indicator of OXPHOS. By combining 8-Cl-Ado with VEN, we observed complete inhibition of OCR, suggesting this drug combination cooperates in targeting OXPHOS and the metabolic homeostasis of AML cells. Conclusion: Taken together, the results suggest that 8-Cl-Ado enhances the antileukemic activity of VEN and that this combination represents a promising therapeutic regimen for treatment of AML. [ABSTRACT FROM AUTHOR]

Lu2O3:Eu single crystals (SCs) and transparent ceramics (TCs) were prepared by the optical floating zone (OFZ) method and hot isostatic pressing (HIP) sintering method, respectively. Their photoluminescence (PL) and scintillation properties, including photoluminescence excitation (PLE) and PL, PL decay, X-ray excited luminescence (XEL) and afterglow level curves, were measured and compared. Their transmission spectra were also recorded. The differences of the PL and scintillation performance between the Lu2O3:Eu SC and TC have been studied. It is shown that the transmittance of the SC is higher than that of the TC, reaching as high as 80%. The Eu(S6) → Eu(C2) energy transfer states in the SC and TC are comparable through investigating the PL and PL decay curves. The main difference between the SC and TC in this work comes from the scintillation luminescence efficiency and afterglow level. The XEL intensity of the SC is 2.4 times that of the TC. The afterglow level of the TC is significantly higher than that of the SC, which probably results from the carrier traps formed in the forbidden gap related to the grain interface in ceramics sample. [ABSTRACT FROM AUTHOR]

The LSC instrument was efficiency calibrated for the tritium activity determination in river water samples by the direct measurement and different LSC cocktails were evaluated in the study. The combined standard uncertainty was around 6% at the coverage factor k = 1. The background tritium, total beta- and 137Cs activity concentrations in the Neris River samples were assessed. The obtained mean values were 1.5 Bq L− 1, 25 mBq L− 1, and 3.3 mBq L− 1 (MDA), respectively. [ABSTRACT FROM AUTHOR]

For the estimation of the tritium activity in environmental samples, the triple to double coincidence ratio (TDCR) method is standardized for the liquid scintillation counter (LSC). Variation of TDCR with tritium activities, optimization of the region of interest for low-level measurement of tritium, the effect of different quenching agents on the TDCR values, and application of TDCR method for the quantification of ionization quench factor (kB) are discussed in this paper. Relative standard deviation in TDCR values at tritium activity levels of 15–140 Bq/L is found to be less than 1%. The the quench curve equation does not depend on the type of quenching agents. [ABSTRACT FROM AUTHOR]

It is a known fact that phosphate rocks have high levels of natural radioactivity due to the presence of large concentrations of radionuclides. This work aims to estimate radiation exposure and dose levels at Al-Jalamid site in northern Saudi Arabia. Al-Jalamid area is one of the largest reserves of phosphate worldwide. Ma'aden, a Saudi Government public company, owns the mine and is responsible for all mining activities. Phosphate and soil samples collected from Al-Jalamid phosphate mining area have been analysed for their uranium and thorium content by an α-spectrometer using radiochemical techniques. The quantity of radon gas was measured both in groundwater and in the atmosphere (indoor and outdoor) at the site using a portable radiation survey instrument. Groundwater samples collected from wells surrounding the mining area were analysed using a liquid scintillation counter in addition to an α-spectrometer. Finally, it is found that phosphate rock concentrate products cannot be utilized economically based on the standards set by the International Atomic Energy Agency (IAEA), since the average activity concentration does not reach the limit set by IAEA and hence are not commercially feasible. [ABSTRACT FROM AUTHOR]

Nuclear industry advancements and growing concerns about environmental contamination and terrorist activity have increased interest in quantifying radioisotopes in environmental and human samples. Increased presence in the environment, ease of entry into the food chain, nuclear medicine applications, and the possibility of radiological terrorism incidents can lead to human intake of these radionuclides (Radionuclides/Radiation Protection/US EPA (2020). https://www.epa.gov/radiation/radionuclides; Radiation from the Earth (Terrestrial Radiation) (2015) Radiation and Your Health, Centers for Disease Control and Prevention. 7 December. https://www.cdc.gov/nceh/radiation/terrestrial.html). A universal method to screen for and quantify individual radionuclides as well as both levels of alpha and beta emitters would address these concerns. [ABSTRACT FROM AUTHOR]

Low activities of radionuclides in environmental and occupational samples demand for the lower detection limits of the measuring system, which can be achieved by minimizing the source-to-detector distance. Analytical technique to calculate full-energy peak efficiency and total efficiency, self-absorption of sources and a coincidence factor of the NaI cubic scintillation detector with rectangular cavity for rectangular source have been derived. The photon path length of the volumetric sources calculated and determined source self-absorption. The photon attention by rectangular sources and detector cap materials is also calculated. In the experiments gamma aqueous source containing Eu-152 radionuclide covering range from 121 to 1408 keV was used. By comparison analytical method for calculating the full energy peak efficiency and the corrected experimental efficiency values are in good a agreement. [ABSTRACT FROM AUTHOR]

In the case of a radiological or nuclear incident, valuable information could be obtained in a timely manner by using liquid scintillation counting (LSC) technique through fast screening of urine samples from potentially contaminated persons. This work describes the optimization of LSC parameters on PerkinElmer (PE) Tri-Carb and Quantulus GCT series instruments to develop a rapid method for screening urine in an emergency response situation. [ABSTRACT FROM AUTHOR]

Background: Despite its beneficial effects on human life, the nuclear industry has its own risks. Strontium 90 (90Sr) is one of the most dangerous radionuclides produced by the uranium 235 fission, and replaces the bone calcium in the human body, which causes cancer. Ensuring the safety of nuclear facilities to protect employees, people and the environment is among the main goals of nuclear safety. Given close proximity of the Bushehr nuclear power plant to the Persian Gulf and the likelihood of 90Sr leaking into the marine ecosystem, this study aimed to measure this radionuclide in a sample of the bar-tail flathead fish (Platycephalus indicus) found in the Persian Gulf coastline, as people’s main source of food in the region. Materials and Methods: Samples were taken from 10 points around the Persian Gulf coastline. The samples were analyzed using chromatographic extraction by Sr-resin and counted by the Liquid Scintillation Counter. Results: The concentration of strontium 90 measured in the fish samples was 0.252- 0.955 Bq.kg-1. The mean chemical efficiency in this method was 97.34 ± 0.97 percent. Conclusion: The amount of strontium 90 found in these samples was negligible and within the least detectable range. Despite the 10-year activity of Bushehr nuclear power plant, no evidence of contamination with strontium 90 was found. These results will be very useful in assessing the underlying contamination in environmental monitoring programs. [ABSTRACT FROM AUTHOR]

Purpose: Ensartinib is a novel, potent and highly selective inhibitor of anaplastic lymphoma kinase (ALK) that has promising clinical activity and low toxicity in patients with ALK-positive non-small cell lung cancer. This study was conducted to investigate the pharmacokinetics, metabolism and excretion of ensartinib following a single 200 mg/100 μCi oral dose of radiolabeled ensartinib to healthy subjects. Methods: Six healthy male subjects were enrolled and administrated an oral suspension in a fasted state. Blood, urine and feces were collected. Radioactivity concentrations were measured by liquid scintillation counting and plasma concentrations of ensartinib by liquid chromatography-tandem mass spectrometry. Both techniques were applied for metabolite profiling and characterization. Results: The mean total recovery was 101.21% of the radiolabeled dose with 91.00% and 10.21% excreted in feces and urine, respectively. Unchanged ensartinib was the predominant drug-related component in urine and feces, representing 4.39% and 38.12% of the administered dose, respectively. Unchanged ensartinib and its metabolite M465 were the major circulating components, accounting for the same 27.45% of the plasma total radioactivity (AUC0–24h pool), while other circulating metabolites were minor, accounting for less than 10%. Mean Cmax, AUC0–∞,T1/2 and Tmax values for ensartinib in plasma were 185 ng/mL, 3827 h ng/mL, 18.3 h and 3.25 h, respectively. The total radioactivity in plasma was cleared with terminal half-life of 27.2 h. Treatment with ensartinib was well tolerated, and no serious adverse events were reported. Conclusion: It was well tolerated in the six healthy male subjects following a single oral administration of 200 mg/100 μCi dose of ensartinib. Besides unchanged ensartinib, metabolite of M465 was the predominant circulating drug-related component. The drug was primarily eliminated in feces. Clinical trial registration: ClinicalTrials.gov NCT03804541. [ABSTRACT FROM AUTHOR]

An evaluation of various radiometric methods to analyze 226Ra in water has been employed on a set of 10 standard solutions of different concentrations in the range of 1–10 Bq/L−1. The analysis was carried out using well-established procedures by means of gamma-ray, alpha-particle and liquid scintillation spectrometry. The feasibility of the various methods has been quantified in terms of relative standard error and percentage error. Correlations between the various methods have been presented and discussed. In general, good agreement was found in the results of various methodologies, which assures the accuracy of the methods and allows for the validation of instrumentation and procedures. Of the different methods adopted here, a combined procedure for the determination of 226Ra along with 228Ra using Quantulus 1220 ultra-low level background liquid scintillation counting gave the most accurate results.

Distemonanthus benthamianus (Caesalpiniaceae) is a plant from the Cameroon pharmacopoeia very widely used in the treatment of many pathologies among which are gastrointestinal disorders. The main purpose of this study was to assess the healing properties of gastric ulcer from the methanolic extract of Distemonanthus benthamianus and its mechanisms of action. The healing properties of gastric ulcers (chronic ulcer model induced by ethanol and indomethacin) were evaluated in vivo in adult male rats, while the mechanisms of action were evaluated in vitro by anti-inflammatory assay (protein denaturation, cyclooxygenase, and lipoxygenase assays) and immunomodulatory assay (ROS production (using technical chemiluminescence), cytokine (TNF-α, IL-1β, IL-6) production (using ELISA), proliferation of T cells (using liquid scintillation counter), and cytotoxicity (using MTT assay)). The methanolic extract of Distemonanthus benthamianus inhibited protein denaturation (75.63%) and the activities of cyclooxygenase (78.92%) and 5-lipoxygenase (81.54%). The extract also significantly (p < 0.001) inhibited intracellular and extracellular ROS production and T cell proliferation and reduced significantly (p < 0.01 , p < 0.001) TNF-α, IL-1β, IL-6, and PGE2 production. At all doses (125, 250, and 500 mg/kg), the extract significantly reduces the ulceration index and the area of ulceration and significantly increases the mass of gastric mucus. In addition, the extract significantly decreases the level of MDA, significantly increases the activities of catalase and glutathione, and then improves the hematological parameters in sick animals. Histological micrographs show that in the presence of the extract, there is advanced reepithelialization with recovery of the ulcerated epithelium. Thus, the extract of Distemonanthus benthamianus has healing properties against gastric ulcers which are associated with its anti-inflammatory, immunomodulatory, and antioxidant effects. [ABSTRACT FROM AUTHOR]

We recently presented the construction of a proportional counter for the absolute measurement of low-energy x-ray emission rates. Its main features were presented in a previous study, along with the testing of its performance as an absolute technique. Full details on its design, construction, and characterization processes are given in this paper. First, the analytical calculations and Monte Carlo simulations that led to the choice of optimal dimensions will be presented, followed by the study of the charge creation and the modeling of the electric field that confirmed that the criteria for a reproducible charge multiplication are met. Afterward, details on the electronics and gas control system will be provided. The dimensional measurements for the accurate determination of the solid angle will be described in detail. Special emphasis will be placed on the production of the detector window, which was made of reduced graphene oxide instead of beryllium. Some tests on the operation of the counter will be presented, namely, the measurement of spectra of several radionuclides that emit x-rays between 3 keV and 9 keV, as well as the fluorescence spectrum of chlorine, at 2.6 keV. A brief explanation of the determination of emission rates will be given, including the approach adopted for the treatment of the escape-peak area. The emission rate measured with the proportional counter was converted into activity concentration using the emission probabilities from the bibliography, in order to compare the results with those obtained by liquid scintillation counting, and both results were found to be in good agreement. [ABSTRACT FROM AUTHOR]

A radiochemical method was developed for the accurate 55Fe determination in various radioactive waste, in particular samples contaminated with 241Pu. It consisted of three purification steps based on first ammonium hydroxide precipitation, and then anion exchange separation followed by TRU®-based extraction chromatography. It was characterized by an iron recovery yield of about 80% for all the studied samples and a 60Co decontamination factor of 106. In comparison to a standard protocol based on iron cupferrate extraction in chloroform, an improvement of a 30-fold factor was achieved towards plutonium. The developed TRU®-based procedure was validated by participating in interlaboratory exercises. [ABSTRACT FROM AUTHOR]

Following a radiological or nuclear incident, the National Response Plan has given the Department of Health and Human Services/Centers for Disease Control and Prevention the responsibility for assessing population's contamination with radionuclides. In the public health response to the incident, valuable information could be obtained in a timely and accurate manner by using liquid scintillation counting techniques to determine who has been contaminated above background for alpha and beta emitting radionuclides. The calibration plays a major role in this process therefore, knowing the effect of quench agents on calibration is essential. [ABSTRACT FROM AUTHOR]

Based on triple-to-double coincidence ratio (TDCR) Cerenkov measurement, a rapid screening method for the analysis of 32P in urine samples was developed. In this method, urine samples were pre-treated to decompose organics by adding concentrated HCl and H2O2 with heating at 60 °C for 1 h and at 90 °C for 30 min. Acetic acid was then added, and the samples were cooled to ambient temperature before counting in Cerenkov mode using a Hidex 300SLL TDCR liquid scintillation counter. An empirical formula between Cerenkov counting efficiency of 32P and the TDCR value was established to correct for color quenching present in the processed samples. The performance of the method was examined using several sets of urine spike samples, and the measurements agreed very well with the expected 32P activities. The detection limit of 11 Bq L−1 was achieved for 15 mL of urine sample with a counting time of 30 min. [ABSTRACT FROM AUTHOR]

We present the validation of a radiochemical procedure for the determination of 55Fe and 63Ni in water and steel samples from nuclear decommissioning activities. The in-house validation was an essential requirement of the accreditation to ISO/IEC 17025. A combination of co-precipitation, anion chromatography and extraction chromatography steps was used for separating and purifying both radionuclides. The activities were measured by liquid scintillation counting. Due to the lack of reference materials, the method was validated by analysing simulated samples and by the standard addition technique. The parameters precision/accuracy, repeatability/linearity, selectivity/specificity, decision threshold, detection limit and uncertainty of the method were evaluated. [ABSTRACT FROM AUTHOR]

This paper proposes a joint measurement method of Ra-226 and Ra-228 in water. Radium was extracted from aqueous samples and analyzed by liquid scintillation counting (LSC). The spectrum and counts measured by LSC is combined with the standard spectrum, and then the activities of Ra-226 and Ra-228 can be calculated by the stripping method. Chemical yields of radium were determined by measuring the chemical analogue (barium) tracer by atomic absorption spectrometry (AAS). The accuracy of the method was verified by measuring mixtures containing varying proportions of Ra-226 and Ra-228. [ABSTRACT FROM AUTHOR]

Rationale: Tritium (3H) is an important hydrological tracer that has been commonly used for over 60 years to evaluate water residence times and water dynamics in shallow/recent groundwaters, streams, lakes and the ocean. We tested the analytical performance of 78 international laboratories engaged in low‐level 3H assays for water age dating and monitoring of environmental waters. Methods: Seven test waters were distributed by the IAEA to 78 international tritium laboratories. Set 1 included a tritium‐free groundwater plus three ultra‐low 3H samples (0.5–7 TU) for meeting groundwater dating specifications. Set 2 contained three higher 3H‐content samples (40–500 TU) suitable for testing of environmental monitoring laboratories. Results: Seventy of the laboratories used liquid scintillation counting with or without electrolytic enrichment, seven utilized 3He accumulation and mass spectrometry, and one used gas‐proportional counting. Only ~50% of laboratories demonstrated the ability to generate accurate 3H data that was precise enough for water age dating purposes. Conclusions: The proficiency test helped identify recurrent weaknesses and potential solutions. Strategies for performance improvements of 3H laboratories include: (a) improved quantification of 3H detection limits and analytical uncertainty, (b) stricter quality control practices in routine operations along with care and recalibration of 3H standards traceable to primary NIST standards, (c) annual assessment of tritium enrichment factors and instrumental performance, and (d) for water age dating purposes the use of electrolytic enrichment systems having the highest possible 3H enrichment factors (e.g. >50×). [ABSTRACT FROM AUTHOR]

The article presents two cryo-electron microscopy structures of Niemann-Pick C1-Like 1 (NPC1L1), one in its apo form and the other complexed with ezetimibe. It mentions the findings that provide insight into the molecular mechanisms of NPC1L1-mediated cholesterol transport and ezetimibe inhibition, paving the way for more effective therapeutic development.

The study was conducted in Trabzon province wherein north-east Turkey and situated on the Black Sea coast. The population of Trabzon city center is 317 520 people. The tritium concentration in the human body is estimated by measuring the activity concentration of tritium in urine. In this context, urine samples was taken and analyzed from 100 participants living in households determined by Turkey Statistical Institute. Tritium concentrations in the samples were measured by the liquid scintillation counter (LSC). The ages of participants range from 18 to 65, with the average is 34.99. The average tritium concentration in their urine samples was found as 13.37 ± 2.33 Bq L-1 and the maximum 33.23 Bq L-1. The MDA for this method was 2.59 Bq L-1. The tritium concentrations of 23 samples (23%) were below of the MDA. The average tritium concentrations in urine samples of females and males were found as 13.45 ± 2.39 Bq L-1 and 13.32 ± 2.30 Bq L-1, respectively. Also, the annual effective dose rates were calculated as 11.13 nSv for females and 12.78 nSv for males. Calculated annual effective dose rates are quite lower than the recommended values by International Commission on Radiological Protection (ICRP). [ABSTRACT FROM AUTHOR]

Tritium breeding performance of a fusion blanket is a key parameter for the self-sufficient fueling of a fusion reactor, and thus designed to validate the performance of a neutronics experiment. Measuring the 2-D distribution of bred tritium is challenging via conventional methods such as $\beta $ -ray counting from an irradiated lithium sample using a liquid scintillation counter (LSC) and a single-crystal diamond detector with a thin 6LiF film, because they are point detectors which require many measurements. In this article, 2-D distribution of the low quantity produced tritium was evaluated with a neutron imaging plate (NIP) with a Gd convertor by estimating the loss of neutrons via a capture reaction by Li. Deuterium–deuterium (DD) fusion neutrons were generated using a compact fusion device at an average neutron production rate of $1.5 \times 10 ^{5}$ n/s by applying high voltages. A neutron image with “shadows” projected by thermal neutron capture reactions of 6Li(n, $\alpha$) and 10B(n, $\alpha$) was successfully obtained. The experimentally evaluated values were confirmed to be consistent with the total number of capture reactions calculated using a neutron transport code. The results suggest that the approach could be a facile method for the 2-D evaluation of bred tritium. [ABSTRACT FROM AUTHOR]

In this study, radon concentration measurements and chemical analyses of groundwater samples were performed in four sampling locations of Bartın Province of Western Black Sea Region, Turkey. 222Rn analysis was carried out in groundwater samples with liquid scintillation counting system in accordance with ASTM D5072 standard. The pH, total hardness, alkalinity and dissolved oxygen parameters of the groundwater samples were also determined. The radon concentrations for the water samples ranged between <3.00 Bq/L–12.03 Bq/L. Thirty eight percentage of the samples slightly exceeded the permissible limit of 11.1 Bq/L specified by USEPA for drinking waters. The annual effective doses of groundwater samples were calculated in the range of 7.41–30.74 μSv/y for ingestion of water (Ew.Ig), and in the range of 7.31–30.31 μSv/y for inhalation of radon released from water (Ew.Ih). The total calculated annual effective doses due to ingestion and inhalation were found to be below the limit value of 100 μSv/y specified by the World Health Organization (WHO). The radioactivity measurement results significantly varied for three sampling points but not for one sampling point on two different measurement dates, which is attributed to the differences in geological structure. The chemical analysis results, except for total hardness in two sampling points, were within the permissible limits specified by international standards. [ABSTRACT FROM AUTHOR]

Groundwater wells in Al- Rusaifah in central Jordan were investigated for radon (222Rn) levels during the winter season using a liquid scintillation counter (LSC). 222Rn was detected in eighteen groundwater samples from six different wells. The concentrations of radon varied from 151.9 to 253.1 Bq/L. The upper concentration limit of 222Rn for drinking water is 11 Bq/L based on the Jordanian Standards for Drinking Purposes. This indicates that 222Rn levels in all groundwater samples exceed the permissible threshold. The health impact assessment of 222Rn showed that for all samples, the total populationweighted average annual effective dose was 3.147mSv/y, which is greater than the maximum value of the general annual effective dose from radon of 0.1 mSv/y, according to the WHO and the European Council. [ABSTRACT FROM AUTHOR]

The article discusses a study examining the effects of a deep-sea mining experiment on seafloor microbial communities and functions after 26 years. It mentions that the author revisited the only midsize deep-sea disturbance and recolonization experiment carried out in 1989 in the Peru Basin nodule field to compare habitat integrity, remineralization rates, and carbon flow with undisturbed sites. It also mentions that plough tracks were still visible.

Uranium is a naturally occurring radioactive element present throughout the environment, atmosphere, food, soil, rocks, and natural waters along with Pb, Cr, As, Zn & Fe. The exposure to the elements may rise in the cases wherever potable water is obtained directly from geogenically affected ground water sources. The uranium impacts are primarily from its chemical activities, instead of long-run tomographical toxic effects, which may lead to urinary organ damage and its non functional. Uranium in 17% ground water samples has been found beyond limit along with other health effecting toxic metals (Pb, Cr, Mn, Fe, As, Zn) in Fatehpur district, Uttar Pradesh bordered by Ganga and Yamuna rivers in the north and south respectively. The affirmative values of uranium on liquid scintillation counter was observed in positive correlation with chromium and lead near the interface of the saturated-unsaturated zone, while zinc, arsenic and iron were very poorly correlated. [ABSTRACT FROM AUTHOR]

Water samples from different origins (rain, surface and drinking) collected in Portugal during the years 2006 to 2017 were analyzed for the tritium (3H) activity contents using isotopic enrichment followed by liquid scintillation counting. Regarding rainwater, the results show no significant correlation between the normalized 3H and the precipitation amount and no variations among the annual seasons. The higher 3H values observed for Tejo River indicate the influence of the Almaraz NPP located in Spain. The 3H activity levels in drinking water were one to two orders of magnitude lower than the European parametric value (100 Bq L−1). [ABSTRACT FROM AUTHOR]

A new dipping method was studied for the measurement of radioactive solution using plastic scintillator sheets and pellets (PSs) and a liquid scintillation counter. The method consists of analyzing the PSs dipped into test solution composed of nine compounds with five different radionuclides, and measuring them by using the 'in solution' and 'without solution' method. A qualitative analysis based on the obtained spectra and a quantitative analysis by using the empirical linear relationships between radioactivity and count rate were possible. Minimum detectable activities of this method were calculated and compared with World Health Organization guidelines for drinking water. [ABSTRACT FROM AUTHOR]

Drinking water may contain radioactive substances that could present a risk to human health (WHO, Guidelines for drinking-water quality: fourth edition incorporating the first addendum. World Health Organization, Geneva, 2017). Of particular significance for human radiation exposure from drinking water are the naturally occurring radionuclides that originate from the elements of the thorium and uranium decay series, such as 226Ra and 228Ra. These radionuclides can arise in water from natural processes in the ground or human activities involving naturally occurring radioactive materials (WHO, Management of radioactivity in drinking water. World Health Organization, Geneva, 2018). The measurement of radioactivity in drinking water allows the determination of population exposure to radiation by the habitual consumption of water. The aim of this study was to determine gross alpha and gross beta activities, and 226Ra and 228Ra activity concentrations in 28 drinking water samples from the Vojvodina region, in order to check compliance with recent Serbian and European regulations. Gross alpha and beta activity in drinking water samples were determined according to ASTM D7283-06 Standard test method for alpha- and beta-activity in water by liquid scintillation counting (ASTM D7283-06, Standard test method for alpha- and beta- activity in water by liquid scintillation counting. ASTM International West Conshohocken PA, https://www.astm.org, 2006), and measured by PerkinElmer liquid scintillation counter Quantulus 1220. The activity of 226Ra and 228Ra was determined by low-level gamma-spectrometry, and assuming the radioactive equilibrium between 226 and 228Ra and their progenies. For the analyzed radionuclides activity concentration in the water samples dose calculations were carried out. Gross alpha activity for all presented water samples exceeded the recommended guideline activity concentrations of 0.1 Bq L−1 (WHO, Guidelines for drinking-water quality, 2nd edn. World Health Organization, Geneva, 1993). The activity concentrations for 226Ra in 13 of investigated samples are higher than the legally established levels for radionuclide content in drinking water in Serbia and EU (Official Gazette, Rulebook on limits of radionuclides content in drinking water, foodstuffs, feeding stuffs, medicines, general use products, construction materials and other goods that are put on market, 2013; EC, Council Directive 2013/51/EURATOM, 2013). In 16 water samples concentration of 228Ra is higher than recommended. In 20 investigated samples, total dose GD from radionuclides in drinking water is higher than 0.1 mSv year−1 (EC, European Drinking Water Directive 98/83/EC of 3 November 1998 European Commission on the quality of water intended for human consumption. Off J L, 1998). The cancer risk caused by the intake of radium isotopes in drinking water during the lifetime was estimated, and the obtaining results are ranged in the acceptable cancer incidence (WHO, Guidelines for drinking-water quality, 4th edn. World Health Organization, Geneva, 2011; EPA, Cancer risk coefficients for environmental exposures to radionuclides. Environmental Protection Agency, Washington, DC, 1999). The presence of 226Ra and 228Ra are explained on the basis of geological and hydrogeological characteristics of the Vojvodina region. [ABSTRACT FROM AUTHOR]

Liquid Scintillation Counting (LSC) is the most commonly used technique for quantification of 14C in the environmental samples. An optimization study was carried out for the analysis of 14C with the direct carbon dioxide absorption method using LSC. The absorption capacity of CO2 in varying amounts of CO2 absorber Carbo-Sorb E to Permafluor scintillation cocktail volumes is found to be 5.33 ± 0.053 mmol/mL of Carbo-Sorb E. The optimum volume ratio of Carbo-Sorb E to Permafluor scintillation cocktail is found to be 1:1 based on the minimum detection activity (MDA) values. The effect of CO2 loading in the optimized absorption mixture shows that with an increasing CO2 amount (up to saturation) there is an increase in tSIE values which is due to an increase of Compton scattering effect in the CO2 loaded samples. The region of interest (ROI) for 14C measurement is found to be 10–96 keV based on the figure of merit values and the efficiency for detecting 14C is 83.45 % in the optimized ROI window. [ABSTRACT FROM AUTHOR]

Understanding the risks of a developing unconventional hydrocarbons industry, including shale gas, to the chemical quality of surface water and groundwater involves firstly establishing baseline compositions against which any future changes can be assessed. Contaminants of geogenic origin are of particular interest and radon has been identified as one potential contaminant from shale sources. Robust measurement and monitoring of radon in water at environmental concentrations is essential for ensuring protection of water sources and maintaining public confidence. Traditional techniques for Rn-222 determination in water, such as inference by gamma spectrometry and direct alpha counting, are impractical for direct field measurement, and the relatively short half-life of Rn-222 (~ 3.82 days) means that longer analytical protocols from field to the laboratory may result in greater uncertainty for Rn-222 activity. Therefore, a rapid and low-cost method would be beneficial. We have developed and refined a laboratory procedure for Rn-222 monitoring using liquid scintillation counting (LSC). The accuracy of Rn-222 activities obtained via this procedure was evaluated by the analysis of almost 200 water samples collected from streams and boreholes as part of a detailed baseline investigation in the Vale of Pickering, Yorkshire, one potential location for future shale gas exploration. LSC was preferred for measurement of Rn-222 and had comparable accuracy to gamma spectrometry and direct alpha counting. The methodology provided a rapid, portable and low-maintenance option relative to the two established techniques and is shown to be a favourable choice for the measurement of radon in surface water and groundwater at environmental concentrations. [ABSTRACT FROM AUTHOR]

• Protein arginine methyltransferases (PRMTs) methylate protein arginyl groups. • PRMTs use S-adenosyl- L -methionine (AdoMet or SAM) as the methyl donor. • Rates of PRMT methylation are easily measured using [ methyl- 3H]-AdoMet and ZipTips® • Reactions for a full rate curve can be processed by ZipTips® in ~30 min • The ZipTip method directly measures radiolabeled product • The method reviewed requires no other equipment than a scintillation counter Protein arginine methylation is a widespread eukaryotic posttranslational modification that occurs to both histone and non-histone proteins. The S-adenosyl- L -methionine (AdoMet or SAM)-dependent modification is catalyzed by the protein arginine methyltransferase (PRMT) family of enzymes. In the last several years a series of both direct and indirect assay formats have been described that allow the rate of methylation to be measured. Here we provide a detailed protocol to directly measure PRMT activity using radiolabeled AdoMet, reversed-phase resin-filled pipette tips (ZipTips®) and a liquid scintillation counter. Because the ZipTips® based quantitation relies only on the straightforward separation of unreacted AdoMet from a methylated substrate, this protocol should be readily adaptable to other methyltransferases. The method is fast, simple to employ with both peptide and protein substrates, and produces very little radioactive waste. [ABSTRACT FROM AUTHOR]

Objective: To explore the immunomodulatory, anti-inflammatory, anti-oxidant and anti-arthritic activity of aqueous and methanolic extracts of Nauclea pobeguinii stem bark. Methods: For in vitro assays, the production of reactive oxygen species (chemiluminescence technique), the proliferation of T cells (liquid scintillation counter method), as well as the inhibition of cyclooxygenase, lipoxygenase, protein denaturation, and free radicals [DPPH, ABTS and nitric oxide (NO) inhibition methods] were evaluated. For in vivo assays, a polyarthritis model was induced by complete Freund's adjuvant in rats. The aqueous and methanolic extracts of Nauclea pobeguinii stem bark were administered orally at 150 and 300 mg/kg. After 28 days of treatment, the total blood was taken to quantify the hematological parameters and the serum was used to evaluate the biochemical parameters (alanine aminotransferase, aspartate transaminase, phenylalnine ammonialyase, and proteins) and oxidative stress parameters (malondialdehyde, catalase, superoxide dismutase, glutathione and NO), and then the knee joint was removed for histological analysis. Results: The extracts of Nauclea pobeguinii significantly reduced the production of intra- and extracellular reactive oxygen species and decreased T cell proliferation. They had an inhibitory effect on cyclooxygenase, lipoxygenase, and protein denaturation, and both extracts had antioxidant capacity on DPPH, ABTS and NO. Both extracts alleviated joint inflammation and pain sensitivity after complete Freund's adjuvant injection, reduced alanine aminotransferase, aspartate transaminase, alkaline phosphatase, NO and malondialdehyde levels, increased protein concentration, superoxide dismutase, catalase and glutathione activity, and restored the cytoarchitecture of the joint after complete Freund's adjuvant injection. Conclusions: The aqueous and methanolic extracts of Nauclea pobeguinii have immunomodulatory, anti-inflammatory, anti-oxidant and anti-arthritic properties. [ABSTRACT FROM AUTHOR]

The triple-to-double coincidence ratio (TDCR) method is a liquid scintillation primary method for the absolute activity measurement of pure β − and pure electron capture emitters. This method requires specific three-photomultiplier liquid scintillation counters. The aim of the present work is to assess the TDCR method performance for routine tritium analysis in urine using an HIDEX 300 SL, the only three-photomultiplier liquid scintillation counter designed for routine laboratories. The physical parameters and the semi-empirical Birks parameter (kB) of the prepared liquid scintillation source were firstly determined. TDCR model equations solving and detection efficiencies calculations for measured samples were performed by TDCR07c computing program. Accuracy, uncertainties and detection limit of TDCR method were assessed through the tritium analysis of six intercomparison urine samples. The results demonstrate that the analytical performance of the TDCR method implemented on the HIDEX 300 SL is conform to the recommendations for the monitoring of workers exposed to tritium. [ABSTRACT FROM AUTHOR]

Due to food safety concerns, the European Food Safety Authority (EFSA) asked to identify useful parameters for identifying the mechanically separated meat (MSM). In this work, the 90Sr levels of MSM products were assessed for evaluating the suitability of this parameter for MSM identification. Indeed, this contaminant may accumulate in animal bones and bone fragments may be present in MSM. One hundred samples of fresh meats and meat products composed of different MSM percentages and without MSM were analyzed by ultra-low-level liquid scintillation counting. The 90Sr activity concentrations detected in meat products with high percentage of MSM were significantly higher (p ≥ 0.05) (0.099 Bq kg−1) than those of fresh meats (0.024 Bq kg−1) and meat products containing low percentage of MSM (0.011 Bq kg−1). The percentage of correct MSM identification was 61%. In order to increase this percentage and to develop a new tool of investigation, the 90Sr was elaborated in combination with other three parameters: 88Sr, Ca and ash percentage, through a multivariate approach. The precision of this tool of investigation was significantly increased (87%), higher than the reference method (Ca level) (76%), representing a valid novel approach in the identification of MSM products. [ABSTRACT FROM AUTHOR]

We addressed how advanced glycation (AGE) affects the ability of apoA-IV to impair inflammation and restore the expression of genes involved in cholesterol efflux in lipopolysaccharide- (LPS-) treated macrophages. Recombinant human apoA-IV was nonenzymatically glycated by incubation with glycolaldehyde (GAD), incubated with cholesterol-loaded bone marrow-derived macrophages (BMDMs), and then stimulated with LPS prior to measurement of proinflammatory cytokines by ELISA. Genes involved in cholesterol efflux were quantified by RT-qPCR, and cholesterol efflux was measured by liquid scintillation counting. Carboxymethyllysine (CML) and pyrraline (PYR) levels, determined by Liquid Chromatography-Mass Spectrometry (LC-MS/MS), were greater in AGE-modified apoA-IV (AGE-apoA-IV) compared to unmodified-apoA-IV. AGE-apoA-IV inhibited expression of interleukin 6 (Il6), TNF-alpha (Tnf), IL-1 beta (Il1b), toll-like receptor 4 (Tlr4), tumor necrosis factor receptor-associated factor 6 (Traf6), Janus kinase 2/signal transducer and activator of transcription 3 (Jak2/Stat3), nuclear factor kappa B (Nfkb), and AGE receptor 1 (Ddost) as well as IL-6 and TNF-alpha secretion. AGE-apoA-IV alone did not change cholesterol efflux or ABCA-1 levels but was unable to restore the LPS-induced reduction in expression of Abca1 and Abcg1. AGE-apoA-IV inhibited inflammation but lost its ability to counteract the LPS-induced changes in expression of genes involved in macrophage cholesterol efflux that may contribute to atherosclerosis. [ABSTRACT FROM AUTHOR]

Based on the requirements of the lower detection limit for the low-volume gaseous effluent, we have designed an automatic separation apparatus of krypton (Kr). The principle of the apparatus is based on both the adsorption and desorption mechanism in the traps with the activated carbon particles and gas chromatography with 5A molecular sieves. The separation efficiency and overall recovery rate could be maintained at about (90.4 ± 4.2)% and (24.3 ± 1.3)%. The 85Kr could be radioassayed on a liquid scintillation counter following the automatic separation and loading into the cryogenic count vial. The detection limit based the low-volume of 3 L is about 9.5 Bq m−3, and the expanded relative uncertainties are in the range of 13–18% for typical measurements. [ABSTRACT FROM AUTHOR]

Lead-210 is a useful tracer in environmental studies for a wide range of applications, particularly in atmospheric research and geochronology. Liquid scintillation counting (LSC) is a commonly used measurement method for 210Pb analysis. In the present work, to increase detection efficiency, an improved LSC technique for 210Pb determination was developed. After adding lead carrier, samples were decomposed with mineral acid in closed digestion vessels. Using extraction chromatography with Sr resin, 210Pb was selectively separated and precipitated as lead oxalate. Following re-dissolution, the solution was mixed with a scintillation cocktail and measured by a liquid scintillation counter. In this study, all the spectral regions with peaks of 210Pb, 210Bi, and 210Po were used to calculate the activity of 210Pb; this is in contrast to the existing method, which divides the spectra into three regions according to energy level, and then selects only the 210Pb region. The method in this study also addresses a procedure for correcting blank values to account for 210Pb activity in the Pb2+ carrier. This measurement technique, using the spectral regions of 210Pb, 210Bi, and 210Po, exhibited more than twice the detection efficiency of the conventional method using only the 210Pb spectrum region. This measurement technique is expected to be a useful method for 210Pb analysis of environmental samples that show low activity, and when sample amounts are limited. [ABSTRACT FROM AUTHOR]

The elevated concentration of 210Po attached to aerosol particles inside a non-ferrous metal refinery was studied. The aerosols were collected on Petrianov or glass-fiber filters and subsequently subjected to radiochemical procedure consisting of acid leaching and concentration by micro co-precipitation with manganese oxide. For the activity determination alpha spectrometry and liquid scintillation counting (LSC) were applied. The obtained results showed that usually observed polonium concentration inside the plant was lower than 78 mBq m−3, however short spikes up to 7430 ± 710 mBq m−3 (related to the specific thermal process) were also observed. [ABSTRACT FROM AUTHOR]

A co-precipitation method followed by a liquid–liquid extraction and liquid scintillation counting is validated by applying it to five different types of matrices. In order to test the applicability of the method, complex matrices are selected. This paper shows the implementation and the results of the validation of the method. [ABSTRACT FROM AUTHOR]

We developed a simple 35S separation method that requires relatively small sample volume (about 5 L) and an analysis method that uses a large sample volume counting vial (145 mL) to reduce the sample volume and simplify pretreatment procedures. Laboratory experiments showed that sulfate concentration had no significant effect on 35S measurement. The recovery was 93.0 ± 0.1% and the minimum detectable activity was determined to be 1.0 mBq L−1. Using our method, the measured 35S activities in the spring and rain waters ranged from 19.2 ± 0.6 to 69.5 ± 3.7 mBq L−1 and from 9.9 ± 0.2 to 54.4 ± 1.8 mBq L−1, respectively. Our results suggest that the long-term monitoring data of 35S in rain water and groundwater are needed for the quantitative and accurate estimation of groundwater residence time. [ABSTRACT FROM AUTHOR]

This paper presents radiocarbon (14C) variations in the atmosphere from Ramnicu Valcea, Romania. The samples were collected in the vicinity of the Experimental Pilot Plant for Tritium and Deuterium Separation (PESTD) from the Institute of the Cryogenics and Isotopic Technologies (ICSI) placed about 10 km south from the Ramnicu Valcea city (Romania), in the Govora industrial area. This facility is an experimental project in the national nuclear energy research program, which has the aim of developing technologies for tritium separation from heavy water. It should be noted that in the Govora industrial area operates a 315 MW coal-fired thermoelectric power plant and two chemical plants. In order to determine radiocarbon activity in the atmosphere, samples were collected monthly by absorption of CO2 into sodium hydroxide (NaOH) at Ramnicu Valcea. In addition, control materials (tree leaves, wild vegetation, and grapes), known activity standards, and process blanks (marble) were analyzed. Radiocarbon measurements were performed using the direct absorption method and liquid scintillation counting. The measured Δ14C levels varied between –57‰ and 61‰. The results have a decreasing trend, but due to local influence caused by the continuous production of fossil CO2, we cannot observe Δ14C seasonal variations. [ABSTRACT FROM AUTHOR]

The potential effects of the very effective cystic fibrosis triple combination drug, Elexacaftor/Tezacaftor/Ivacaftor (ETI) in pregnancy on prenatal development of offspring remain largely unknown. We aimed to investigate the fetal tissue distribution pattern of maternally administered ETI by placental transfer in the rat fetuses. Sprague Dawley pregnant rats were administered ETI (6.7 mg/kg/d elexacaftor + 3.5 mg/kg/d tezacaftor + 25 mg/kg/d ivacaftor) traced with [3 H]-ivacaftor in single dose acute experiments (intraperitoneal injection) or treated orally with ETI (the same dose) for 7 days in sub-chronic experiments. Fetal tissue samples were collected at embryonic day (E) 19 and analyzed using liquid scintillation counting for acute experiments or liquid chromatography-mass spectrometry for sub-chronic experiments. On day E19, after acute exposure, the entry of ivacaftor into fetal brain (brain/plasma concentration ratios <50%) was significantly lower than to other tissues (>100%). However, after sub-chronic exposure, the entry of all 3 components into the developing brain was comparably extensive as into other tissues (tissue/plasma ratios, 260 – 1000%). Each component of ETI accumulated in different fetal tissues to approximately equal extent. Inter-litter differences on fetal drug distribution were found in cortex for ivacaftor, muscle for tezacaftor and cortex and mid/hindbrain for elexacaftor. Fetal plasma concentrations of ETI (ng/mL) were variable between litters. The entry of ivacaftor and tezacaftor into adult brain appeared to be restricted (<100%). Fetal rats are exposed to maternally ingested ETI after sub-chronic exposure, potentially impacting fetal development. The brain entry data highlights the need for attention be paid to any long-term potential effects ETI exposure could have on normal brain development. [ABSTRACT FROM AUTHOR]

Screening of aqueous samples for 3H contamination is required to decide suitability of water intended for human consumption during radiation emergency. BARC, Trombay has recently procured Portable Triathler liquid scintillation counter as a screening tool for on-site response to radiation emergency. For this purpose, parameters like, different available scintillators, scintillator to sample ratio and influence of different capacity scintillation vials were optimized for 3H concentration measurement. The study indicated that for 7 mL vials, the optimized scintillator to sample ratio was 4:1 for Optiphase Hisafe II, Ultima Gold Ultra Low Level Tritium, Aqualight AB and Dioxane based scintillators whereas for Ultima Gold AB and Optiphase Hisafe III scintillators it was 3:1. In case of 20 mL vials, the ratio was optimized to 8:1 for all the above mentioned six scintillators. Additionally, the effect of applying counting efficiency using calibration curves generated using distilled water and that obtained using optimized scintillator to sample ratio in various spiked water samples was also studied. Results in 3H concentration (2000–5700 Bq/mL) indicate about ±10% deviation using both the methods for commercially available scintillators. However, in case of Dioxane based scintillator, the deviation was higher (20%). For analysis of 3H concentration ∼200 Bq/mL using commercially available scintillators results in higher deviation of about 21% due to unreliable quench indicating parameter for count rate less than 4000. The study indicated that calibration curves constructed using optimized parameters are universally applicable for determination of 3H concentration in wide variety of water samples. • Optimized sample to scintillator ratio for OP II, UGuLLT, Aqualight AB and Dioxane based scintillators is 4:1 for 7-mL glass vials. It is 3:1 for UGAB and OP III scintillators. • For 20 mL vials, the ratio is 8:1 for all the six scintillators. • Calibration curves constructed using DW for 3H concentration can be universally applied for various matrices under study. • Methodology gives MDA lower than the AERB OIL value. • Maximum recommended 3H concentration that can be reported using Triathler LSC is ∼215 kBq/mL with ±10% deviation. [ABSTRACT FROM AUTHOR]

Pine needles and tree cores from a tritium (T) contaminated phytoremediation forest at the Savannah River Site (SRS in Aiken, SC) Mixed Waste Management Facility (MWMF) were measured for total T and T speciation and compared to other locations at the SRS and the surrounding area. Tree core ages ranged from 9 to 14 years old, covering over half of the ∼20-year on-going remediation efforts, while pine needles represent more recent time periods of 1-to-2-year increments. Remedial irrigation efforts at the MWMF are found to directly influence the pine needle T concentrations. The T content in the MWMF samples is higher than non-irrigated needle samples from other locations around the SRS. Further, the different forms of organic bound T are preferentially stored in tree core tissue, compared to pine needles where tritiated water dominates. [Display omitted] • Tritium is cycled through environmental media. • Tritium is released to environment by nuclear and anthropogenic activities. • Total T and OBT content by sample combustion and liquid scintillation counting. • Pine tree cores and needles are reliable indicators of T exposure. [ABSTRACT FROM AUTHOR]

Gadolinium-153 was standardized for activity by live-timed anticoincidence counting and an ampoule was submitted to the international reference system (SIR). Absolute emission intensities for the main γ rays were determined with calibrated high-purity germanium (HPGe) and lithium-drifted silicon (Si(Li)) detectors. A revised decay scheme is indicated, with no probability of direct electron capture to the 153Eu ground state. Triple-to-double coincidence ratio (TDCR) efficiency curves indicate that the revised decay scheme is consistent with experiment. Half-life measurements agree with a previous NIST determination and show no sensitivity to chemical environment. • Standardization of 153Gd activity by live timed anticoincidence (LTAC) counting • Absolute photon emission intensities measured by gamma ray spectrometry • Efficiencies for triple-to-double coincidence ratio (TDCR) liquid scintillation counting • Data support a decay scheme with no direct electron capture to 153Sm ground state • No sensitivity of measured 153Gd half-life to chemical environment detected [ABSTRACT FROM AUTHOR]

A solution of 225 Ac was standardized by NRC using the triple-to-double coincidence ratio (TDCR) method. The counting efficiencies were calculated assuming a counting efficiency of 100% for alpha decays and those calculated using the MICELLE2 Monte Carlo code for beta decays and was approximately 500% for the NRC TDCR system. The relative uncertainty for the activity concentration was determined to be 0.25%. This agreed with measurements performed using gamma spectroscopy and a predicted calibration factor for the Vinten 671 ionization chamber as calculated using an EGSnrc model, implementing radioactive decay. Finally, the half-life of 225 Ac was determined from long-term measurements using ionization chambers and liquid scintillation counting. The NRC measured half-life for 225 Ac was found to be 9.914(4) days and is consistent within an expanded uncertainty coverage of k = 2 with the most recent (Kossert et al., 2020; Pommé et al., 2012) measurements of this decay parameter. • Standardization of Ac-225 at NRC using the TDCR method. • Half-life determination of Ac-225 at NRC consistent with other recently published values. • Determination of the counting efficiency of Ac-225 in radioactive equilibrium with its progeny. [ABSTRACT FROM AUTHOR]

Terbium-152 is one of four terbium radioisotopes that together form a potential theranostic toolbox for the personalised treatment of tumours. As 152 Tb decay by positron emission it can be utilised for diagnostics by positron emission tomography. For use in radiopharmaceuticals and for activity measurements by an activity calibrator a high radionuclide purity of the material and an accurate and precise knowledge of the half-life is required. Mass-separation and radiochemical purification provide a production route of high purity 152Tb. In the current work, two mass-separated samples from the CERN-ISOLDE facility have been assayed at the National Physical Laboratory to investigate the radionuclide purity. These samples have been used to perform four measurements of the half-life by three independent techniques: high-purity germanium gamma-ray spectrometry, ionisation chamber measurements and liquid scintillation counting. From the four measurement campaigns a half-life of 17.8784(95) h has been determined. The reported half-life shows a significant difference to the currently evaluated half-life (ζ-score = 3.77), with a relative difference of 2.2 % and an order of magnitude improvement in the precision. This work also shows that under controlled conditions the combination of mass-separation and radiochemical separation can provide high-purity 152Tb. • First half-life measurement of 152Tb since 1970. • Precise half-life of 152Tb determined by three independent techniques from mass-separated samples. • Presented half-life value shows a relative difference of 2.2% from current evaluated value. • Order of magnitude improvement in the precision to the current evaluated value. • Radionuclide contaminants from two mass-separated samples assessed. [ABSTRACT FROM AUTHOR]