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Abstract: The French Atomic Energy Commission has carried out several experiments for the study of minor-actinide transmutation processes in high intensity thermal neutron flux. In this context a Cm sample enriched in 248Cm (∼97%) was irradiated in a thermal neutron flux at the High Flux Reactor (HFR) of the Laue–Langevin Institute (ILL). The precise and accurate determination of Cf isotope ratios and of 249Bk/248Cm and 249Cf/248Cm elemental ratios in the 248Cm irradiated sample is crucial for the calculation of actinide neutron capture cross-sections. This work describes an analytical procedure for the separation and the isotope ratio measurement of Bk and Cf in the irradiated sample. The Bk and Cf separation is based on a lanthanides separation protocol previously developed by the laboratory. Well-defined retention times for Bk and Cf were obtained by coupling the Ionic Chromatography (IC) with an ICP-QMS. All conditions of element separation by IC and the different steps of the analytical protocol in order to obtain the isotopic and elemental ratios are presented. Relative uncertainties of Cf isotopic ratios range from 0.3% to 0.5% and the uncertainty of the 249Bk/248Cm and 249Cf/248Cm elemental ratios are respectively 6.1% and 3.2%. This level of uncertainty for both isotopic and elemental ratios is in perfect agreement with the requirement for transmutation studies. [Copyright &y& Elsevier]

Abstract: The French Atomic Energy Commission has carried out several experiments including the mini-INCA (INcineration of Actinides) project for the study of minor-actinide transmutation processes in high intensity thermal neutron fluxes, in view of proposing solutions to reduce the radiotoxicity of long-lived nuclear wastes. In this context, a Cm sample enriched in 248Cm (∼97%) was irradiated in thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). This work describes a quadrupole ICP-MS (ICP-QMS) analytical procedure for precise and accurate isotopic composition determination of Cm before sample irradiation and of Cm and Cf after sample irradiation. The factors that affect the accuracy and reproducibility of isotopic ratio measurements by ICP-QMS, such as peak centre correction, detector dead time, mass bias, abundance sensitivity and hydrides formation, instrumental background, and memory blank were carefully evaluated and corrected. Uncertainties of the isotopic ratios, taking into account internal precision of isotope ratio measurements, peak tailing, and hydrides’ formations ranged from 0.3% to 1.3%. This uncertainties’ range is quite acceptable for the nuclear data to be used in transmutation studies. [Copyright &y& Elsevier]

Abstract: The Th–U cycle was studied through the evolution of a 100μg 232Th sample irradiated in a moderated neutron flux of 8.01014 n/cm2/s, intensity close to that of a thermal molten salt reactor. After 43 days of irradiation and 6 months of cooling, a precise mass spectrometric analysis, using both TIMS and MC-ICP-MS techniques, was performed, according to a rigorous methodology. The measured thorium and uranium isotopic ratios in the final irradiated sample were then compared with integral simulations based on evaluated data; an overall good agreement was seen. Four important thermal neutron-capture cross-sections were also extracted from the measurements, 232Th (7.34±0.21b), 233Pa (38.34±1.78b), 234U (106.12±3.34b), and 235U (98.15±11.24b). Our 232Th and 235U results confirmed existing values whereas the cross-sections of 233Pa and 234U (both key parameters) have been redefined. [Copyright &y& Elsevier]

Abstract: The determination of 93Zr concentration, a long-lived radionuclide present in spent nuclear fuel and in the structural components of nuclear reactors, is a major issue for nuclear waste disposal purpose and to validate neutronic calculation codes. To measure 93Zr concentration in irradiated cladding material with a high precision, an analytical method based on the use of multiple collector-inductively coupled plasma mass spectrometer (MC-ICPMS) combined to isotope dilution technique was developed. First a radiochemical separation of zirconium from a zircaloy sample (a zirconium alloy used as a cladding material for nuclear fuel elements), has allowed to obtain a very pure zirconium fraction with no potential isobaric interferences for mass spectrometric measurements. Then as the determination of all zirconium isotope ratios in the sample is necessary for the isotope dilution method, a MC-ICPMS procedure was developed to perform these precise measurements. Finally, the determination of 93Zr concentration in the same sample was performed, after preparation and calibration of a 96Zr spike solution. The uncertainties obtained on isotope ratios of zirconium by MC-ICPMS were in the order of 0.1%. The final uncertainty obtained on the 93Zr concentration in the nuclear material used and after chemical purification was lower than 0.6%. [Copyright &y& Elsevier]

Abstract: Strontium-90 is one of the most important fission products generated in nuclear industry. In the research field concerning nuclear waste disposal in deep geological environment, it is necessary to quantify accurately and precisely its concentration (or the 90Sr/ 238U atomic ratio) in irradiated fuels. To obtain accurate analysis of radioactive 90Sr, mass spectrometry associated with isotope dilution is the most appropriated method. But, in nuclear fuel samples the interference with 90Zr must be previously eliminated. An inductively coupled plasma mass spectrometer with multiple collection, equipped with an hexapole collision cell, has been used to eliminate the 90Sr/ 90Zr interference by addition of oxygen in the collision cell as a reactant gas. Zr+ ions are converted into ZrO+, whereas Sr+ ions are not reactive. A mixed solution, prepared from a solution of enriched 84Sr and a solution of enriched 235U was then used to quantify the 90Sr/ 238U ratio in spent fuel sample solutions using the double isotope dilution method. This paper shows the results, the reproducibility and the uncertainties that can be obtained with this method to quantify the 90Sr/ 238U atomic ratio in an UOX (uranium oxide) and a MOX (mixed oxide) spent fuel samples using the collision cell of an inductively coupled plasma mass spectrometer with multiple collection to perform the 90Sr/ 90Zr separation. A comparison with the results obtained by inductively coupled plasma mass spectrometer with multiple collection after a chemical separation of strontium from zirconium using a Sr spec resin (Eichrom) has been performed. Finally, to validate the analytical procedure developed, measurements of the same samples have been performed by thermal ionization mass spectrometry, used as an independent technique, after chemical separation of Sr. [Copyright &y& Elsevier]

Abstract: This study describes a new determination of the decay scheme and half-life of 93Zr. A pure 93Zr solution was obtained after chemical separation from the dissolution of an irradiated zircaloy sample. The concentration of 93Zr in the solution was measured by mass spectrometry, with an isotopic dilution technique. The activity of the solution was measured by liquid scintillation counting, using an efficiency tracing method. The measurement of the activity concentration of 93Nbm by X-ray spectrometry, allowed the determination of the 93Zr decay scheme and the calculation of the 93Zr detection efficiency. This leads to the calculation of the decay probability of 93Zr toward 93Nbm of (0.73±0.06) and to a half-life of 93Zr of (1.64±0.06)×106 years. These values are discussed in comparison with the evaluated values available in the literature. [Copyright &y& Elsevier]

Abstract: This study focuses on two radioisotopes of silver, 108mAg and 110mAg, characterized by a complex decay scheme. Each isotope has two disintegration modes, the isomeric transition leading to the daughter isotope (108Ag and 110Ag, respectively) with a short half-life. The radioactive solution was obtained by neutron activation on silver powder enriched in 109Ag. Gamma-spectrometry was carried out using a calibrated high purity germanium detector. The main relative photon emission intensities for both radionuclides were obtained and compared with previously published values. [Copyright &y& Elsevier]

Abstract: In the general frameworks of the nuclear fuel cycle and environmental research field, the Cs isotopic composition must be known with high precision and accuracy. The direct determination of Cs isotopes by mass spectrometry techniques is generally hampered by the presence of Ba isobaric interferences however. Here we present a new method which takes advantage of the collision-reaction cell based Multiple Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) and allows to analyse Cs isotopes in the presence of Ba without prior separation step. The addition of N2O gas in the cell leads to an antagonistic behavior of Cs+ and Ba+ as the latter reacts with the gas to form BaO+ and BaOH+ products whereas Cs+ remains unreactive. The efficiency of the method was demonstrated for an UOx sample by comparing the results obtained (1) from the measurements of pure Cs fractions and (2) from Fission Products fractions containing more than 30 ionisable elements in addition to Cs, Ba, and where U and Pu were previously removed by using ion exchange resin. An excellent agreement is achieved between each set of experiments with an external reproducibility always better than 0.5% (RSD, k =2). This study confirms the strong potential of collision–reaction cell to measure Cs isotopes in presence of interfering Ba, precluding therefore former systematic chemical separations. [Copyright &y& Elsevier]

Abstract: Cholera is a bacterial infection, which causes digestive symptoms and massive diarrhoea. It may lead to dehydration and death if appropriate medical management is not rapidly initiated. Most cases of infection by choleric vibrio, however, remain symptom-free or may mimic common gastroenteritis. A review of two cases of imported cholera in France in the summer of 2005 and the community- and hospital-based investigation, which they triggered, enabled the incident management teams to assess risks of transmission. There were no secondary cases among 58 hospital contacts and 15 family contacts of the cases. Clinicians will find a discussion of possible clinical presentations and the risk of secondary transmission, in the context of progressing epidemics in countries, which have maintained close ties with France. [Copyright &y& Elsevier]

The objective of this work was to develop an actinide-specific monolithic support in capillary designed to immobilize precise Pu:Am ratios and its coupling to inductively coupled plasma mass spectrometry (ICP-MS) for immobilized metal affinity chromatography applications. This format offers many advantages, such as reducing the sample amount and waste production, which are of prime importance when dealing with highly active radioelements. Four organic phosphorylated-based monoliths were synthesized in situ through UV photo-polymerization in capillary and characterized. The capillary coupling to ICP-MS was set up in conventional laboratory using Th and Sm as chemical analogues of Pu and Am. A dedicated method was developed to quantify online Th and Sm amounts immobilized on the monolithic capillaries, allowing to select the best monolith candidate poly(BMEP-co-EDMA) adp . By precisely adjusting the elemental composition in the loading solutions and applying the developed quantification method, the controlled immobilization of several Th:Sm molar ratios onto the monolith was successful. Finally, the capillary ICP-MS coupling was transposed in a glove box and by applying the strategy developed to design the monolithic support using Th and Sm, the immobilization of a 10.5 ± 0.2 (RSD = 2.3%, n = 3) Pu:Am molar ratio reflecting Pu ageing over 48 years was achieved in a controlled manner on poly(BMEP-co-EDMA) adp . Hence, the new affinity capillary monolithic support was validated, with only hundred nanograms or less of engaged radioelements and can be further exploited to precisely determine differential interactions of Pu and Am with targeted biomolecules in order to better anticipate the effect of Am on Pu biodistribution., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

A cyclic tetra-phosphorylated biomimetic peptide (pS1368) has been proposed as a promising starting structure to design a decorporating agent of uranyl (UO 2 2+ ) due to its affinity being similar to that of osteopontin (OPN), a target UO 2 2+ protein in vivo. The determination of this peptide's selectivity towards UO 2 2+ in the presence of competing endogenous elements is also crucial to validate this hypothesis. In this context, the selectivity of pS1368 towards UO 2 2+ in the presence of Ca 2+ , Cu 2+ and Zn 2+ was determined by applying the simultaneous coupling of hydrophilic interaction chromatography (HILIC) to electrospray ionization (ESI-MS) and inductively coupled plasma (ICP-MS) mass spectrometry. Sr 2+ was used as Ca 2+ simulant, providing less challenging ICP-MS measurements. The separation of the complexes by HILIC was first set up. The selectivity of pS1368 towards UO 2 2+ was determined in the presence of Sr 2+ , by adding several proportions of the latter to UO 2 (pS1368). UO 2 2+ was not displaced from UO 2 (pS1368) even in the presence of a ten-fold excess of Sr 2+ . The same approach has been undertaken to demonstrate the selectivity of pS1368 towards UO 2 2+ in the presence of Cu 2+ , Zn 2+ and Sr 2+ as competing endogenous cations. Hence, we showed that pS1368 was selective towards UO 2 2+ in the presence of Sr 2+ , but also in the presence of Cu 2+ and Zn 2+ . This study highlights the performance of HILIC-ESI-MS/ICP-MS simultaneous coupling to assess the potential of molecules as decorporating agents of UO 2 2+ ., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

The 135 Cs/ 137 Cs isotopic ratio is a powerful tool for tracing the origin of radioactive contamination. Since the Fukushima accident, this ratio has been measured by mass spectrometry in several highly contaminated environmental matrices mainly collected near nuclear accident exclusion zones and former nuclear test areas. However, few data were reported at 137 Cs environmental levels (<1 kBq kg -1 ). This is explained by the occurrence of analytical challenges related to the very low radiocesium content at the environmental level with the large presence of mass interferences, making 135 Cs and 137 Cs measurements difficult. To overcome these difficulties, a highly selective procedure for Cs extraction/separation combined with an efficient mass spectrometry measurement must be applied on a quantity of ca. 100 g of soil. In the current research, an innovative inductively coupled plasma-tandem mass spectrometry (ICP-MS/MS) method has been developed for the 135 Cs/ 137 Cs ratio measurement in low activity environmental samples. The use of ICP-MS/MS led to a powerful suppression of 135 Cs and 137 Cs interferences by introducing N 2 O, He, and, for the first time, NH 3 , into the collision-reaction cell. By adjusting the flow rates of these gases, the best compromise between a maximum signal in Cs and an effective interference elimination was achieved allowing a high Cs sensitivity of more than 1.10 5 cps/(ng g -1 ) and low background levels at m/z 135 and 137 lower than 0.6 cps. The accuracy of the developed method was successfully verified by analyzing two certified reference materials (IAEA-330 and IAEA-375) commonly used in the literature as validation samples and three sediment samples collected in the Niida River catchment (Japan) impacted by the Fukushima fallout.

Several proteins have been identified in the past decades as targets of uranyl (UO 2 2+ ) in vivo. However, the molecular interactions responsible for this affinity are still poorly known which requires the identification of the UO 2 2+ coordination sites in these proteins. Biomimetic peptides are efficient chemical tools to characterize these sites. In this work, we developed a dedicated analytical method to determine the affinity of biomimetic, synthetic, multi-phosphorylated peptides for UO 2 2+ and evaluate the effect of several structural parameters of these peptides on this affinity at physiological pH. The analytical strategy was based on the implementation of the simultaneous coupling of hydrophilic interaction chromatography (HILIC) with electrospray ionization mass spectrometry (ESI-MS) and inductively coupled plasma mass spectrometry (ICP-MS). An essential step had been devoted to the definition of the best separation conditions of UO 2 2+ complexes formed with di-phosphorylated peptide isomers and also with peptides of different structure and degrees of phosphorylation. We performed the first separations of several sets of UO 2 2+ complexes by HILIC ever reported in the literature. A dedicated method had then been developed for identifying the separated peptide complexes online by ESI-MS and simultaneously quantifying them by ICP-MS, based on uranium quantification using external calibration. Thus, the affinity of the peptides for UO 2 2+ was determined and made it possible to demonstrate that (i) the increasing number of phosphorylated residues (pSer) promotes the affinity of the peptides for UO 2 2+ , (ii) the position of the pSer in the peptide backbone has very low impact on this affinity (iii) and finally the cyclic structure of the peptide favors the UO 2 2+ complexation in comparison with the linear structure. These results are in agreement with those previously obtained by spectroscopic techniques, which allowed to validate the method. Through this approach, we obtained essential information to better understand the mechanisms of toxicity of UO 2 2+ at the molecular level and to further develop selective decorporating agents by chelation., 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.)

Aim: KCNB1 encephalopathy encompasses a broad phenotypic spectrum associating intellectual disability, behavioral disturbances, and epilepsies of various severity. Using standardized parental questionnaires, we aimed to capture the heterogeneity of the adaptive and behavioral features in a series of patients with KCNB1 pathogenic variants., Methods: We included 25 patients with a KCNB1 encephalopathy, aged from 3.2 to 34.1 years (median = 10 years). Adaptive functioning was assessed in all patients using the French version of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) questionnaire. We screened global behavior with the Childhood Behavioral Check-List (CBCL, Achenbach) and autism spectrum disorder (ASD) with the Social Communication Questionnaire (SCQ). We used a cluster analysis to identify subgroups of adaptive profiles., Results: VABS-II questionnaire showed pathological adaptive behavior in all participants with a severity of adaptive deficiency ranging from mild in 8/20 to severe in 7/20. Eight out of 16 were at risk of Attention Problems at the CBCL and 13/18 were at risk of autism spectrum disorder (ASD). The adaptive behavior composite score significantly decreased with age (Spearman's Rho=-0.72, p<0.001) but not the equivalent ages, suggesting stagnation and slowing but no regression over time. The clustering analysis identified two subgroups of patients, one showing more severe adaptive behavior. The severity of the epilepsy phenotype predicted the severity of the behavioral profile with a sensitivity of 70% and a specificity of 90.9%., Conclusion: This study confirms the deleterious consequences of early-onset epilepsy in addition to the impact of the gene dysfunction in patients with KCNB1 encephalopathy. ASD and attention disorders are frequent. Parental questionnaires should be considered as useful tools for early screening and care adaptation., 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 © 2021. Published by Elsevier Inc.)

Uranium exposure can lead to neurobehavioral alterations in particular of the monoaminergic system, even at non-cytotoxic concentrations. However, the mechanisms of uranium neurotoxicity after non-cytotoxic exposure are still poorly understood. In particular, imaging uranium in neurons at low intracellular concentration is still very challenging. We investigated uranium intracellular localization by means of synchrotron X-ray fluorescence imaging with high spatial resolution (< 300 nm) and high analytical sensitivity (< 1 μg.g -1 per 300 nm pixel). Neuron-like SH-SY5Y human cells differentiated into a dopaminergic phenotype were continuously exposed, for seven days, to a non-cytotoxic concentration (10 μM) of soluble natural uranyl. Cytoplasmic submicron uranium aggregates were observed accounting on average for 62 % of the intracellular uranium content. In some aggregates, uranium and iron were co-localized suggesting common metabolic pathways between uranium and iron storage. Uranium aggregates contained no calcium or phosphorous indicating that detoxification mechanisms in neuron-like cells are different from those described in bone or kidney cells. Uranium intracellular distribution was compared to fluorescently labeled organelles (lysosomes, early and late endosomes) and to fetuin-A, a high affinity uranium-binding protein. A strict correlation could not be evidenced between uranium and the labeled organelles, or with vesicles containing fetuin-A. Our results indicate a new mechanism of uranium cytoplasmic aggregation after non-cytotoxic uranyl exposure that could be involved in neuronal defense through uranium sequestration into less reactive species. The remaining soluble fraction of uranium would be responsible for protein binding and for the resulting neurotoxic effects., (Copyright © 2020 Elsevier B.V. All rights reserved.)