Development and Implementation of a Multi-Element Assay Method Using Laser Ablation Coupled with ICP-MS for the Analysis of Powdered Solids
The activities of the host laboratory within the CEA’s Directorate of Military Applications (DAM) focus on the analysis of small quantities of nuclear material. This study aims to develop and implement a method for elemental analysis in powdered solids, based on the coupling of a laser ablation (LA) device with an inductively coupled plasma mass spectrometer (ICPMS). The method developed must cover a wide range of concentrations, from ultra-trace levels (ng/g) to minor and major elements. Sample preparation will be performed by alkaline fusion to form glass pellets, ensuring good spatial homogeneity of the elements to be analyzed. For certain applications, up to forty chemical elements will need to be analyzed.
Measurements will be performed using a 213-nm nanosecond UV laser and a high-resolution ICPMS (Thermo-Fisher “Element XR”) located in a controlled area. The target samples are labeled soils and uranium ore concentrates. Part of this work will be conducted in collaboration with the European Joint Research Center (JRC) in Karlsruhe, Germany, which is also equipped with a multi-collection LA-ICPMS system (Thermo-Fisher “Neoma”).
Extraction Protocols for the GC-Orbitrap Analysis of Organic Compounds in Nuclear Matrices
The analysis of persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and other persistent organic compounds, primarily relies on gas chromatography coupled with mass spectrometry (GC-MS), the reference technique for their identification and quantification. However, complex matrices from the nuclear sector (sludges, soot, ashes, soils, concrete, etc.) require dedicated sample preparation protocols to ensure reliable analytical results. Interactions between contaminants and the solid matrix, particularly adsorption phenomena, may significantly reduce extraction efficiency.
The objective of this project is to develop and validate robust extraction protocols for the analysis of these contaminants using high-resolution GC-Orbitrap mass spectrometry. Following a comprehensive literature review, the successful candidate will define an experimental strategy, evaluate and compare different sample preparation and extraction methods, and validate the selected protocols before applying them to representative nuclear matrices.
The postdoctoral position will be based at the Institute for Research on Nuclear Systems for Low-Carbon Energy (IRESNE) at CEA Cadarache, France. The successful candidate will develop expertise in the analytical chemistry of complex matrices, with a particular focus on sample preparation, organic contaminant extraction, and GC-Orbitrap analysis. They will design and validate innovative analytical protocols while addressing the specific challenges associated with nuclear matrices. The research outcomes will be disseminated through publications in peer-reviewed journals and presentations at national and international scientific conferences.
Diamond-based electrochemical sensors for monitoring water pollution in urban environments
This postdoctoral position is offered by CEA List as part of the European UrbaQuantum project ("A novel, Integrated Approach to Urban Water Quality Monitoring, Management and Valorisation"), part of the HORIZON-CL6-2024-ZEROPOLLUTION-02 call for projects. The main objective of this project is to develop, in response to climate change, sensors, models, and protocols for better management of the water cycle in urban environments.
At the Sensors and Instrumentation for Measurement Laboratory (LCIM)of CEA List the postdoctoral fellow will contribute to the development of electrochemical sensors based on synthetic diamond and associated measurement protocols for the detection of pollutants such as pharmaceuticals, heavy metals, PFAS, and pesticides. These sensors will be miniaturized and integrated into a microfluidic cell, in partnership with CEA-Leti, then tested under real-world field conditions.
Separation microsystem coupled to mass spectrometry for on-line purification and characterisation of nuclear samples
The miniaturisation of analytical steps commonly carried out in laboratories offers many advantages and particularly in the nuclear sector, where the reduction of material consumption and waste production is of major interest. In this context, one of our laboratory’s focus area is the miniaturisation of analytical tools, particularly chromatographic separation techniques. The aim of this project is to reduce the scale of the purification steps of nuclear samples by solid phase extraction chromatography, prior to the analytical processes. Obtaining these miniaturised extraction devices is based on the in situ synthesis and anchoring of monoliths, in the channels of cyclic olefin copolymer (COC) microsystems. Since this material is chemically inert, COC functionalisation strategies are currently under development to covalently graft reactive sites on its surface, before locally anchoring actinide-specific monoliths in the micro-channels. The aim is to design and fabricate chromatographic extraction microsystems in COC, and to implement them for chemical purification and mass spectrometry measurements, both off-line and on-line.
Leaching foams to extract metals from electronic waste
The subject is part of the ANR "Foamex" project covering TRL from 1 to 5 and focussing on the development of recycling of some metals from a shred of electronic cards, this recycling being carried out in a fluid foam (minimization of the volume of solvents) that can be considered at the first level as a dynamic chromatography column. The principle is to use the foam as a reservoir containing an acid solution and specific oxidizing agents to dissolve and extract metals in the form of ionic species, a phenomenon enhanced by friction between bubbles and simultaneously to concentrate them via the fluid and mobile liquid/air interfaces by flow.
Development of methods for U quantification in cells after exposure to uranium
This project fits into the transverse Toxicology Program, led by CEA, whose purpose is to address by multidisciplinary approaches, the potential effects on living organisms of elements of strategic interest to the CEA. The objective is to provide some understanding on the mechanisms of uranium toxicity and behavior, in connection with its speciation in cells. Indeed, the radionuclides speciation governs their bioavailability, accumulation, biodistribution, toxicity, detoxification mechanisms and their interaction at the molecular level.
The post-doctoral project (12 months) consists in:
- Developing methods to quantify U accumulated in the cells as well as endogenous content of trace elements after exposure of cells to uranium.
- Developing methods to determine the precise isotopic composition of U in the cells after their exposure.
The candidate will be in charge of developing chemical purification and measurement methods for precise elemental and isotopic analyses. The analyses will be performed using inductively coupled plasma quadrupole mass spectrometer (ICP- MS Q) or inductively coupled plasma multi- collection mass spectrometer of the latest generation (ICP- MS MC), to achieve the lowest level of uncertainties.
Gas sensors based on diamond nanoparticles and nanoporous materials
The aim is to develop surface acoustic wave sensors (SAW) with high sensitivity and high selectivity to gaseous compounds (< 100 ppb). The development strategy involves the use of diamond nanoparticles based guiding layers deposited on the piezoelectric substrate and chemically modified to tune the specificity of the sensors. In order to increase further the selectivity, the sensors will be coupled to specific filters placed before the sensors and based on probe molecules trapped in porous sol-gel based materials and able to react non-reversibly with interferent molecules. The topic includes 4 mains sections: 1) synthesis and functionalisation of diamond nanoparticles, 2) study of probe molecules and immobilisation in porous matrices, 3) study of the filtering capacity of the filters toward relevant interferent species, 4) metrology and calibration of the sensors. This work will be carried out in the "Diamond Sensors Laboratory" as well as laboratoire Francis Perrin both located in CEA Saclay.
Detection of traces of narcotics in saliva by electrochemiluminescence on diamond electrodes
The consumption of narcotics is becoming a problem for road safety because 23% of road deaths in France occur in an accident involving at least one driver who tested positive. Thus, one objective of road safety in consultation with the concerned ministries (Ministry of Transport, Ministry of Interior, Ministry of Health and Ministry of Economy) is to improve the fight against road insecurity linked to narcotics consumption. In particular, this involves increasing and facilitating roadside checks using a portable device dedicated to controlling the use of narcotics on the roadside, similar to what is already done for breathalyzer tests. Such a device is not commercially available today. The main prerequisites of this device will be to provide reliable, immediate confirmation results with evidentiary value for the courts as well as a purchase cost compatible with large-scale deployment on French road networks. In this context, the subject of study proposed aims to study the possible detection of traces of narcotics in saliva using electroluminescence on a boron-doped diamond electrode. This method is considered promising for such an application because it potentially allows extremely low detection thresholds to be reached and, in accordance with legislative requirements, offers multiple possibilities aimed at achieving high selectivity towards chemical targets, with a high detection capacity. miniaturization of equipment and a relatively low cost of apparatus compared to analytical tools such as mass spectrometer, IMS, etc.