PubMed | Institute For Hygiene Und Umwelt, National Water Research Institute, Servicio de Radioisotopos, Physikalische Chemie and 23 more.
Type: | Journal: Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine | Year: 2016
The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training.
Grenier M.,CNRS Geophysical Research and Oceanographic Laboratory |
Jeandel C.,CNRS Geophysical Research and Oceanographic Laboratory |
Lacan F.,CNRS Geophysical Research and Oceanographic Laboratory |
Vance D.,University of Bristol |
And 5 more authors.
Journal of Geophysical Research: Oceans | Year: 2013
Neodymium isotopic compositions (εNd) and rare earth element (REE) concentrations were measured for filtered surface to deep waters (112 samples) in the Southern Tropical Pacific. The relatively detailed picture of these tracer distributions allowed us to refine the areas where oceanic εNd variations occur. εNd values increase for most of the water masses flowing from Samoa to the Solomon Sea and in the Papua New Guinea (PNG) area, as already observed. Furthermore, water masses arriving from the eastern equatorial Pacific (200-550m depth) also revealed radiogenic values, possibly acquired in the vicinity of the South American coasts and Galapagos Islands. These εNd variations affect the whole water column. The most likely process causing such variations is "boundary exchange" between the numerous radiogenic slopes/margins located in this area and seawater flowing past. Dissolution of atmospheric deposition and/or diffuse streaming of volcanic ash are also suggested to explain the radiogenic εNd observed at the surface in the PNG area. Interestingly, a positive europium (Eu) anomaly characterizes the normalized REE patterns of most of the studied water masses. This anomaly is consistent with the REE patterns of sediment and rock samples that are potential sources for the local waters. Such consistency reinforces the hypothesis that lithogenic sources play a major role in the oceanic REE budget, thanks to "boundary exchange." The data set presented here is a good basis for further sampling that will be realized in the framework of the ongoing GEOTRACES program (www.geotraces.org). © 2012 American Geophysical Union. All Rights Reserved.
Pedreschi R.,Institute for Reference Materials and Measurements IRMM |
Norgaard J.,Institute for Reference Materials and Measurements IRMM |
Maquet A.,Institute for Reference Materials and Measurements IRMM
Nutrients | Year: 2012
There is a need for selective and sensitive methods to detect the presence of food allergens at trace levels in highly processed food products. In this work, a combination of non-targeted and targeted proteomics approaches are used to illustrate the difficulties encountered in the detection of the major peanut allergens Ara h 1, Ara h 2 and Ara h 3 from a representative processed food matrix. Shotgun proteomics was employed for selection of the proteotypic peptides for targeted approaches via selective reaction monitoring. Peanut presence through detection of the proteotypic Ara h 3/4 peptides AHVQVVDSNGNR (m/z 432.5, 3+) and SPDIYNPQAGSLK (m/z 695.4, 2+) was confirmed and the developed method was able to detect peanut presence at trace levels (≥10 μg peanut g -1 matrix) in baked cookies. © 2012 by the authors; licensee MDPI, Basel, Switzerland.
Tudora A.,University of Bucharest |
Hambsch F.-J.,Institute for Reference Materials and Measurements IRMM
Annals of Nuclear Energy | Year: 2010
The prompt neutron multiplicity distribution P(v) is a very sensitive quantity which depends on the model calculation of the multi-parametric matrix v(A,TKE) and on the fission fragment distributions. The Point by Point model is able to give an excellent description of the existing P(v) experimental data, this fact being exemplified in the present work for the following seven fissioning systems: 235U(nth,f), 239Pu(n th,f), 252Cf(SF), 248,244Cm(SF), 240,242Pu(SF).Taking into account the high sensitivity of P(v) to the accuracy of the model used to calculate the matrix v(A,TKE), the good agreement of the Point by Point model results with the experimental P(v) data can be considered as a very important validation test for the Point by Point model itself and for the models and methods used to obtain the Point by Point model parameters. © 2010 Elsevier Ltd. All rights reserved.
De Girolamo A.,CNR Institute of Sciences of Food Production |
Solfrizzo M.,CNR Institute of Sciences of Food Production |
Lattanzio V.M.T.,CNR Institute of Sciences of Food Production |
Stroka J.,Institute for Reference Materials and Measurements IRMM |
And 3 more authors.
World Mycotoxin Journal | Year: 2013
The results of a proficiency test for the LC-MS/(MS) determination of up to 11 mycotoxins (aflatoxins B1, B2, G1 and G2, fumonisins B1 and B2, ochratoxin A, deoxynivalenol, T-2 and HT-2 toxins and zearalenone) in maize were evaluated to identify possible strengths and weaknesses of various methodologies used by the 41 participating laboratories. The majority of laboratories (56%) used mixtures of acetonitrile:water for extraction. Other laboratories used methanol:water mixtures (17%) or performed two consecutive extractions with phosphate buffer solution (PBS) followed by methanol (15%). Few laboratories used mixtures of acetonitrile:water:methanol (7%), water:ethyl acetate (2.5%) or PBS alone (2.5%). The majority of laboratories (58%) used a clean-up step prior to chromatography. The remaining laboratories analysed crude extracts (37%) or used a mixed approach (5%). The amount of sample equivalent injected into LC-MS/(MS) ranged between 0.1-303 mg for purified extracts and 0.08-20 mg for directly analysed crude extracts. External (54%), matrix-matched (22%) or stable isotope-labelled internal standards calibration (24%) were used for toxin quantification. In general, extraction mixtures of water with acetonitrile, methanol or both provided good results for quantitative extraction of mycotoxins from maize. Laboratories using sample extract clean-up reported acceptable results for the majority of mycotoxins. Good results were also obtained by laboratories that analysed crude extracts although a high variability of results was observed for all tested mycotoxins. Matrix-matched calibration or isotope-labelled internal standards efficiently compensated matrix effects whereas external calibration gave reliable results by injecting â‰10 mg of matrix equivalent amounts. Unacceptable high recovery and high variability of fumonisin results were obtained by the majority of laboratories, which could not be explained and thus require further investigation. These findings provide the basis for the optimization and selection of methods to be used in future interlaboratory validation studies to derive their performance characteristics for simultaneous determination of mycotoxins in maize.
Otuka N.,International Atomic Energy Agency |
Borella A.,Institute for Reference Materials and Measurements IRMM |
Kopecky S.,Institute for Reference Materials and Measurements IRMM |
Lampoudis C.,Institute for Reference Materials and Measurements IRMM |
Schillebeeckx P.,Institute for Reference Materials and Measurements IRMM
Journal of the Korean Physical Society | Year: 2011
A data format for time-of-flight spectra (transmission, reaction and self-indication yields) and their covariance matrices based on the AGS (Analysis of Geel Spectra) format is discussed in collaboration between EC-JRC IRMM and IAEA-NDS for the EXFOR library. Experimentalists are encouraged to consider the uncertainty propagation following the AGS principle and submission of their data to the International Networks Nuclear Reaction Data Centres (NRDC) for EXFOR compilation using a proposed template.
Lovestam G.,Institute for Reference Materials and Measurements IRMM |
Nolte R.,Physikalisch - Technische Bundesanstalt |
Roberts N.,National Physical Laboratory United Kingdom
Metrologia | Year: 2014
Neutron reference fields in the energy range above 15 MeV are produced using the T(d,n)4He reaction and solid-state Ti(T) targets. The potential presence of non-monoenergetic neutrons from parasitic (d,n) reactions induced in the target materials makes this energy range particularly challenging for reference instruments which cannot discriminate the neutron energy, such as long counters or activation foils. Therefore, a supplementary comparison was carried out in the energy range from 15.5 MeV to 19 MeV involving reference instruments of different sensitivities to non-monoenergetic neutrons. The spectral distributions of the neutron beams were characterized by time-of-flight measurements and by Monte Carlo simulations.
Loeschner K.,Technical University of Denmark |
Navratilova J.,Technical University of Denmark |
Legros S.,University of Vienna |
Wagner S.,University of Vienna |
And 4 more authors.
Journal of Chromatography A | Year: 2013
Asymmetric flow field-flow fractionation (AF4) in combination with on-line optical detection and mass spectrometry is one of the most promising methods for separation and quantification of nanoparticles (NPs) in complex matrices including food. However, to obtain meaningful results regarding especially the NP size distribution a number of parameters influencing the separation need to be optimized. This paper describes the development of a separation method for polyvinylpyrrolidone-stabilized silver nanoparticles (AgNPs) in aqueous suspension. Carrier liquid composition, membrane material, cross flow rate and spacer height were shown to have a significant influence on the recoveries and retention times of the nanoparticles. Focus time and focus flow rate were optimized with regard to minimum elution of AgNPs in the void volume. The developed method was successfully tested for injected masses of AgNPs from 0.2 to 5.0μg. The on-line combination of AF4 with detection methods including ICP-MS, light absorbance and light scattering was helpful because each detector provided different types of information about the eluting NP fraction. Differences in the time-resolved appearance of the signals obtained by the three detection methods were explained based on the physical origin of the signal. Two different approaches for conversion of retention times of AgNPs to their corresponding sizes and size distributions were tested and compared, namely size calibration with polystyrene nanoparticles (PSNPs) and calculations of size based on AF4 theory. Fraction collection followed by transmission electron microscopy was performed to confirm the obtained size distributions and to obtain further information regarding the AgNP shape. Characteristics of the absorbance spectra were used to confirm the presence of non-spherical AgNP. © 2012 Elsevier B.V.
Roebben G.,Institute for Reference Materials and Measurements IRMM |
Linsinger T.,Institute for Reference Materials and Measurements IRMM |
Lamberty A.,Institute for Reference Materials and Measurements IRMM |
Emons H.,Institute for Reference Materials and Measurements IRMM
Metrologia | Year: 2010
Global comparability of the measured values of material properties is based on some fundamental metrological concepts. These concepts are either already widely implemented in current procedures for materials testing or they are being further developed and increasingly accepted and used. An important aspect of the comparability of measurement results is metrological traceability. This paper aims at illustrating with practical examples how to apply the concept of metrological traceability as defined in ISO/IEC Guide 99:2007, known also as the VIM (International Vocabulary of Metrology), in the field of engineering material properties. VIM distinguishes three different types of references for traceability: either to a system of units, such as the SI, to a measurement procedure or to a physical measurement standard. For each approach, an example is given in the field of engineering material properties, including appropriate traceability statements and means to achieve the traceability. The role of certified reference materials is highlighted, as well as practical consequences of traceability requirements for the design of reference material certification projects. © 2010 BIPM & IOP Publishing Ltd.
Solfrizzo M.,National Research Council Italy |
De Girolamo A.,National Research Council Italy |
Gambacorta L.,National Research Council Italy |
Visconti A.,National Research Council Italy |
And 2 more authors.
Journal of AOAC International | Year: 2011
A liquid chromatographic method for the determination of fumonisins B 1 (FB1) and B2(FB2) in corn-based foods for infants and young children was subjected to an interlaboratory validation study involving 11 laboratories. Five blind duplicate sample pairs of each matrix were analyzed to establish the accuracy, repeatability, and reproducibility of the method. Mass fractions in the baby food samples ranged from 89.1 to 384.4 μg/kg FB1 and from 22.5 to 73.6 μg/kg FB2. The method involved a warm extraction with citrate phosphate buffer-methanol-acetonitrile (50 + 25 + 25, v/v/v), a cleanup through an immunoaffinity column, and an end-determination of fumonisins by LC after automated precolumn derivatization with o-phthaldialdehyde reagent. RSDs for withinlaboratory repeatability (RSDr) ranged from 6.8 to 23.5% for FB1 and 7.6 to 22.9% for FB2. RSDs for between-laboratory reproducibility (RSDR) ranged from 15.4 to 26.2% for FB1 and 21.6 to 36.3% for FB2. Mean FB1 recoveries from baby foods spiked at 100.0 and 250.0 μg/kg were 89 and 96%, respectively; for FB2 spiked foods at 25.0 and 62.5 μg/kg recoveries were 90 and 85%, respectively. HorRat values ranged from 0.8 to 1.2 for FB1, whereas for FB2 they ranged from 0.9 to 1.4 when calculated according to Horwitz, and from 1.0 to 1.7 when calculated according to Thompson, indicating an acceptable amonglaboratory precision for all matrixes (HorRat values <2).