L’exposition cutanée aux nanoparticules métalliques: Développement d’un modèle expérimental pour l’étude de la décontamination de la peau après une exposition aux nanoparticules métalliques

National audienceBien que les possibilités de pénétration cutanée des nanoparticules jusqu’à la circulation systémique semblent faibles sur peau saine, les plus petites nanoparticules pourraient franchir la peau via les follicules pileux, les glandes sudoripares ou voie intercellulaire et constituer des réservoirs au niveau de la peau. Dans le cas des nanoparticules métalliques , leur dissolution pourrait conduire à des effets locaux de type dermatite ou sensibilisation liés aux ions métalliques libérés. Une des questions importantes en cas de contamination accidentelle de la peau est de savoir comment la nettoyer efficacement. L’objectif de cette étude de faisabilité est de développer un modèle expérimental adapté pour l’étude de la décontamination de la peau à des nanoparticules de type métallique : argent (Ag) et dioxyde de titane (TiO2). Le développement d’une méthode répond non seulement aux attentes concrètes des médecins du travail, mais il pourra aussi être extrapolé à la population générale

Comments on “A Simple, Rapid, Comparative Evaluation of Multiple Products for Decontamination of Actinide-contaminated Rat Skin Ex Vivo “

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OPTIMIZATION OF 226RA URINE EXTRACTION FOR INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (ICP-MS) ANALYSIS

International audienceRadium 226 has been identified as a highly radiotoxic radionuclide with a high potential of malevolence uses. In radiological emergency situations and for medical monitoring of nuclear workers, urine analysis is the more convenient to estimate the effective dose. A lot of methods for radium analysis in urine have been described in the literature, differing from the time of preparation and analysis and detection limit. Based on the protocol defined by Cozzella and al. in 2011(1) who used the Dowex® 50W-X8 resin, the urine extraction procedure of 226Ra was optimized for ICP-MS analysis in order to realize the extraction as fast as possible with a detection limit adapted to highlight an effective dose of 1 mSv. Besides this optimization, the contribution of polyatomic interferences as 88Sr138Ba, very common interference for 226Ra measurement by ICP-MS, was determined and taken into account in our results. First results showed that the radium extraction on Dowex® 50W-X8 resin was not complete in our experimental conditions. Two hypothesis could explain these results: the saturation of the resin or the acid conditions that are not optimal for the radium extraction on Dowex® 50W-X8 resin. To improve these results, some experiments were performed:-Determination of the distribution coefficient of 226Ra on Dowex® 50W-X8 to adapt the preconditionement of the resin and optimize the radium elution step,-Determination of the maximal capacity of Dowex® 50W-X8 resin for radium extraction,-Optimization of the procedure with a mineralization step after the co-precipitation of radium in order to eliminate the organic matter which prevent the radium extraction on the resin.Besides that, two other resins were also tested: -The Analig® Ra-01, a specific resin for radium, that has been applied by Verlinde et al. for water analysis (2),-The calix-[6]-arene based column that has been developed for actinides in urine by Bouvier-Capely et al.(1)Cozzella M.L. et al. Determination of 226Ra in urine samples by Q-ICP-MS : a method for routine analyses. Radiat Meas. 2011 ; 46 : 109-111.(2)Verlinde M. and al. A new protocol for 226Ra separation and preconcentration in natural water sample using molecular recognition technology for ICP-MS analysis. J Environ Radioact. 2019 ; 202 : 1-7.(3)Bouvier-Capely et al. Operational protocol for detection of contamination by actinides U, Pu and Am in urine using Calixarene columns : from mineralization to ICP-MS measurement. Am J Anal Chem. 2017 ; 8 : 317-333

OPTIMIZATION OF 226RA URINE EXTRACTION FOR INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (ICP-MS) ANALYSIS

International audienceRadium 226 has been identified as a highly radiotoxic radionuclide with a high potential of malevolence uses. In radiological emergency situations and for medical monitoring of nuclear workers, urine analysis is the more convenient to estimate the effective dose. A lot of methods for radium analysis in urine have been described in the literature, differing from the time of preparation and analysis and detection limit. Based on the protocol defined by Cozzella and al. in 2011(1) who used the Dowex® 50W-X8 resin, the urine extraction procedure of 226Ra was optimized for ICP-MS analysis in order to realize the extraction as fast as possible with a detection limit adapted to highlight an effective dose of 1 mSv. Besides this optimization, the contribution of polyatomic interferences as 88Sr138Ba, very common interference for 226Ra measurement by ICP-MS, was determined and taken into account in our results. First results showed that the radium extraction on Dowex® 50W-X8 resin was not complete in our experimental conditions. Two hypothesis could explain these results: the saturation of the resin or the acid conditions that are not optimal for the radium extraction on Dowex® 50W-X8 resin. To improve these results, some experiments were performed:-Determination of the distribution coefficient of 226Ra on Dowex® 50W-X8 to adapt the preconditionement of the resin and optimize the radium elution step,-Determination of the maximal capacity of Dowex® 50W-X8 resin for radium extraction,-Optimization of the procedure with a mineralization step after the co-precipitation of radium in order to eliminate the organic matter which prevent the radium extraction on the resin.Besides that, two other resins were also tested: -The Analig® Ra-01, a specific resin for radium, that has been applied by Verlinde et al. for water analysis (2),-The calix-[6]-arene based column that has been developed for actinides in urine by Bouvier-Capely et al.(1)Cozzella M.L. et al. Determination of 226Ra in urine samples by Q-ICP-MS : a method for routine analyses. Radiat Meas. 2011 ; 46 : 109-111.(2)Verlinde M. and al. A new protocol for 226Ra separation and preconcentration in natural water sample using molecular recognition technology for ICP-MS analysis. J Environ Radioact. 2019 ; 202 : 1-7.(3)Bouvier-Capely et al. Operational protocol for detection of contamination by actinides U, Pu and Am in urine using Calixarene columns : from mineralization to ICP-MS measurement. Am J Anal Chem. 2017 ; 8 : 317-333

OPTIMIZATION OF 226RA URINE EXTRACTION FOR INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (ICP-MS) ANALYSIS

International audienceRadium 226 has been identified as a highly radiotoxic radionuclide with a high potential of malevolence uses. In radiological emergency situations and for medical monitoring of nuclear workers, urine analysis is the more convenient to estimate the effective dose. A lot of methods for radium analysis in urine have been described in the literature, differing from the time of preparation and analysis and detection limit. Based on the protocol defined by Cozzella and al. in 2011(1) who used the Dowex® 50W-X8 resin, the urine extraction procedure of 226Ra was optimized for ICP-MS analysis in order to realize the extraction as fast as possible with a detection limit adapted to highlight an effective dose of 1 mSv. Besides this optimization, the contribution of polyatomic interferences as 88Sr138Ba, very common interference for 226Ra measurement by ICP-MS, was determined and taken into account in our results. First results showed that the radium extraction on Dowex® 50W-X8 resin was not complete in our experimental conditions. Two hypothesis could explain these results: the saturation of the resin or the acid conditions that are not optimal for the radium extraction on Dowex® 50W-X8 resin. To improve these results, some experiments were performed:-Determination of the distribution coefficient of 226Ra on Dowex® 50W-X8 to adapt the preconditionement of the resin and optimize the radium elution step,-Determination of the maximal capacity of Dowex® 50W-X8 resin for radium extraction,-Optimization of the procedure with a mineralization step after the co-precipitation of radium in order to eliminate the organic matter which prevent the radium extraction on the resin.Besides that, two other resins were also tested: -The Analig® Ra-01, a specific resin for radium, that has been applied by Verlinde et al. for water analysis (2),-The calix-[6]-arene based column that has been developed for actinides in urine by Bouvier-Capely et al.(1)Cozzella M.L. et al. Determination of 226Ra in urine samples by Q-ICP-MS : a method for routine analyses. Radiat Meas. 2011 ; 46 : 109-111.(2)Verlinde M. and al. A new protocol for 226Ra separation and preconcentration in natural water sample using molecular recognition technology for ICP-MS analysis. J Environ Radioact. 2019 ; 202 : 1-7.(3)Bouvier-Capely et al. Operational protocol for detection of contamination by actinides U, Pu and Am in urine using Calixarene columns : from mineralization to ICP-MS measurement. Am J Anal Chem. 2017 ; 8 : 317-333

Solvent extraction of U(VI) by calix[6]arenes

This paper focuses on the solvent extraction of U(VI) traces by 1,3,5-OMe-2,4,6-OCH2CONHOH-p-tert-butylcalix[6]arene (LH3). The global extraction equation of U(VI) has been established. The complex formed in the organic phase is (UO2) (LH) with an apparent extraction constant equal to 7.1×10-5 M(I =0.04 M). Distribution data show that LH3 efficiently extracts U(VI) from NaNO3 media at pH 5 and that the stripping of U(VI) can be achieved in nitric acid solutions. Finally a comparison with previous results obtained with the 1,3,5-OMe-2,4,6-OCH2COOH-p-tert-butylcalix[6]arene (L′H3) shows that the hydroxamate groups are as efficient as the carboxylate ones for uranyl extraction. Copyright © Taylor & Francis Group, LLC

An alternative procedure for uranium analysis in drinking water using AQUALIX columns: Application to varied French bottled waters

The general population is chronically exposed to uranium (234U, 235U, and 238U) and polonium (210Po) mainly through day-to-day food and beverage intake. The measurement of these naturally-occurring radionuclides in drinking water is important to assess their health impact. In this work the applicability of calix[6]arene-derivatives columns for uranium analysis in drinking water was investigated. A simple and effective method was proposed on a specific column called AQUALIX, for the separation and preconcentration of U from drinking water. This procedure is suitable for routine analysis and the analysis time is considerably shortened (around 4 h) by combining the separation on AQUALIX with fast ICP-MS measurement. This new method was tested on different French bottled waters (still mineral water, sparkling mineral water, and spring water). Then, the case of simultaneous presence of uranium and polonium in water was considered due to interferences in alpha spectrometry measurement. A protocol was proposed using a first usual step of spontaneous deposition of polonium on silver disc in order to separate Po, followed by the uranium extraction on AQUALIX column before alpha spectrometry counting. © 2013 Elsevier B.V

Potentialities of mass spectrometry (ICP-MS) for actinides determination in urine

The applicability of inductively coupled plasma-mass spectrometry (ICP-MS) for determining actinides in urine was investigated. Performances of ICP-MS including detection limit and analysis time were studied and compared with α spectrometry performances. In the field of individual monitoring of workers, the comparison chart obtained in this study can be used as a guide for medical laboratories to select the most adequate procedure to be carried out depending on the case in question (the radioisotope to be measured, the required sensitivity, and the desired response time). © 2004 Elsevier Ltd. All rights reserved

The use of calix[6]arene molecules for actinides analysis in urine: an alternative to current procedures

Individual monitoring of workers exposed to a risk of internal contamination with actinides is achieved through in vivo measurements (anthroporadiametry) and in vitro measurements (urine and feces). The procedures currently used for analyzing actinides in urine require lengthy separation associated with long counting times by alpha spectrometry due to low activity levels. Their main drawback is thus that they are time-consuming, which limits the frequency and flexibility of individual monitoring. In this context, the aim of this work, carried out by the Radiochemistry Laboratory at the Institute for Radiological Protection and Nuclear Safety (IRSN), is to propose alternative radiochemical procedures for the analysis of actinides U, Pu and Am in urine. In order to selectively extract actinides from urines, it is of interest to use calix[n]arene molecules. Indeed, the preorganized structure of these macrocyclic molecules is suitable for the complexation of ions and they can be easily functionalized to be more specific. Thus, the p-tertbutylcalix[6]arenes bearing three carboxylic acid groups or three hydroxamic acid groups are excellent extractants for uranium, and they have also a very good affinity for plutonium and americium. The extraction of actinides by these calixarene has been studied experimentally, and also by computational study for uranium. From these results, a new radiochemical procedure has been proposed for U, Pu, Am analysis in urine. For an application to bioassays laboratories, it was decided to immobilize the calix[6]arene molecules on an inert solid support, for implementation with a chromatographic column. This technique makes it possible to combine the extraction performances of the calix[6]arenes with the practical advantages of the chromatographic column. Consequently, this new radiochemical is well suited for routine analysis. Furthermore, the actinides separation is quantitative and reproducible, and is faster and easier than the current procedures