Search

Stable hydrogen, carbon, nitrogen, oxygen and sulfur (HCNOS) isotope compositions expressed as isotope-delta values are typically reported relative to international standards such as Vienna Standard Mean Ocean Water (VSMOW), Vienna Peedee belemnite (VPDB) or Vienna Cañon Diablo Troilite (VCDT). These international standards are chosen by convention and the calibration methods used to realise them in practice undergo occasional changes. To ensure longevity and reusability of published data, a comprehensive description of (1) analytical procedure, (2) traceability, (3) data processing, and (4) uncertainty evaluation is required. Following earlier International Union of Pure and Applied Chemistry documents on terminology and notations, this paper proposes minimum requirements for publishing HCNOS stable-isotope delta results. Each of the requirements are presented with illustrative examples.

The processes of planetary accretion or formation of the Earth and other celestial objects can be studied by using the ¹⁸²Hf-¹⁸²W chronometer which requires precise measurements of tungsten isotope ratios. Many comparative measurements for the isotopic composition of tungsten have been performed using either thermal ionization mass spectrometry (TIMS) or multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Yet, calibrated measurements of tungsten isotope ratios, and, in turn, isotopic abundances and atomic weight, are still lacking. In this study, we report the first independent measurements of all tungsten isotope ratios in five commercial tungsten reagents, including the new NRC candidate isotopic reference material WOLF-1 by MC-ICP-MS with use of the-state-of-the-art optimized regression mass bias correction model and NIST SRM 989 isotopic rhenium as calibrator.

International audience; Mixotrophic microorganisms are able to use organic carbon as well as inorganic carbon sources and thus, play an essential role in the biogeochemical carbon cycle. In aquatic ecosystems, the alteration of carbon dioxide (CO2) fixation by toxic metals such as cadmium – classified as a priority pollutant – could contribute to the unbalance of the carbon cycle. In consequence, the investigation of cadmium impact on carbon assimilation in mixotrophic microorganisms is of high interest. We exposed the mixotrophic microalga Chlamydomonas reinhardtii to cadmium in a growth medium containing both CO2 and labelled 13C‐[1,2] acetate as carbon sources. We showed that the accumulation of cadmium in the pyrenoid, where it was predominantly bound to sulphur ligands, impaired CO2 fixation to the benefit of acetate assimilation. Transmission electron microscopy (TEM)/X‐ray energy dispersive spectroscopy (X‐EDS) and micro X‐ray fluorescence (μXRF)/micro X‐ray absorption near‐edge structure (μXANES) at Cd LIII‐edge indicated the localization and the speciation of cadmium in the cellular structure. In addition, nanoscale secondary ion mass spectrometry (NanoSIMS) analysis of the 13C/12C ratio in pyrenoid and starch granules revealed the origin of carbon sources. The fraction of carbon in starch originating from CO2 decreased from 73 to 39% during cadmium stress. For the first time, the complementary use of high‐resolution elemental and isotopic imaging techniques allowed relating the impact of cadmium at the subcellular level with carbon assimilation in a mixotrophic microalga.

Com a finalidade de otimizar a produção, a irradiação e a quantificação de iodo-125 utilizado na confecção de sementes de iodo para braquiterapia, uma metodologia teórico-experimental foi aplicada baseada no procedimento proposto por COSTA, O. L., 2015, em que iodo-125 é obtido via ativação neutrônica no reator nuclear IEA-R1 a partir da irradiação de xenônio-124 encapsulado em compartimentos de alumínio. Após todo o preparo das amostras seguindo o processo descrito, iniciou-se o processo de irradiação sob o fluxo de nêutrons da ordem de 1013 nêutrons.cm-2.s-1 por diferentes períodos de tempo. Foram irradiadas seis cápsulas (duas contendo Xe-124 natural e quatro contendo Xe-124 enriquecido 99,9%) a fim de comparar a atividade total produzida variando o parâmetro de enriquecimento da amostra. Depois de serem irradiadas, as capsulas foram abertas e lavadas em meio alcalino aquecido para extração do iodo depositado nas paredes internas. As soluções geradas foram armazenadas em diferentes frascos padrões de acrílico, nomeadas e quantificadas via espectrometria gama com Detector de Germânio Hiperpuro (HPGe ORTEC modelo GEM-C5970-B) para determinação da pureza do radionuclídeo de interesse. Para calibração do HPGe foi aplicada uma metodologia experimental utilizando uma fonte de calibração certificada de bário-133 com atividade bem conhecida em que as eficiências dos fotopicos energéticos foram medidos entre 0 - 667 keV. As curvas de eficiência foram determinadas para uma faixa de energia que cobrissem toda a região de interesse espectral para o iodo-125 e seus subprodutos gerados na reação nuclear, além disso, elas foram construídas para diferentes distâncias da janela do detector e dimensões do frasco padrão de análise. No processo de ativação, iodo-126 foi formado como subproduto indesejado, esse radionuclídeo foi quantificado e sua atividade determinada. Finalmente, foi possível determinar a pureza radionuclídica do iodo-125 e compará-la com as exigências internacionais de qualidade que regulam a produção de medicamentos radioativos. In order to optimize the production, irradiation and quantification of iodine-125 used in the manufacture of iodine seeds for brachytherapy, a theoretical-experimental methodology was applied based on the procedure proposed by COSTA, O. L, 2015, in which iodine-125 it is obtained via neutron activation in the nuclear reactor IEA-R1 from the irradiation of xenon-124 encapsulated in aluminum compartments. After all the preparation of the samples following the described process, the irradiation process started under the neutron flux in the order of 1013 neutrons.cm-2.s-1 for different periods of time. Six capsules were irradiated (two containing natural Xe-124 and four containing 99.9% enriched Xe-124) in order to compare the total activity produced by varying the sample enrichment parameter. After being irradiated, the capsules were opened and washed in a heated alkaline medium to extract the iodine deposited on the inner walls. The generated solutions were stored in different standard acrylic flasks, named and quantified via gamma spectrometry with Hyperpure Germanium Detector (HPGe ORTEC model GEM-C5970-B) to determine the purity of the radionuclide of interest. To calibrate the HPGe, an experimental methodology was applied using a certified barium-133 calibration source with well-known activity in which the efficiency of the energy photopics were measured between 0 - 667 keV. The efficiency curves were determined for an energy range that covered the entire region of spectral interest for iodine-125 and its by-products generated in the nuclear reaction, in addition, the efficiency curves were constructed for different distances from the detector window and dimensions of the standard analysis flask. In the activation process, iodine-126 was formed as an unwanted by-product, this radionuclide was quantified and its activity determined. Finally, it was possible to determine the radionuclide purity of iodine-125 and compare it with the international quality requirements that regulate the production of radioactive drugs.

BACKGROUND The use of PDO (protected designation of origin) and PGI (protected geographical indication) labels allows to protect and promote agricultural products characterized by unique features related to the place of origin and traditional know‐how. However, the presence of non‐authentic products in the market represents a fraud that can be tackled applying analytical techniques combined with chemometric analysis. In this study, we applied multi‐element and multi‐isotope analysis to characterize PDO and PGI apples cultivated in northern Italy, comparing them with Italian apples without labels of geographical indications. RESULTS The multi‐element and multi‐isotope approach allowed to characterize the apples cultivated in northern Italy. Despite a significant effect of the sampling sites on the apple composition, the comparison of the multi‐chemical fingerprint of the apples significantly varied among cultivation areas. Results of this characterization were used to classify samples according to their cultivation area applying a linear discriminant analysis (LDA). Outputs of the LDA showed that correct sample classification can be successfully achieved (balanced accuracy > 96%). Moreover, using a selection of variables, it was possible to correctly classify samples also at regional level. CONCLUSION The presented evidences indicate that the multi‐element and multi‐isotope fingerprint can be successfully applied to traceability studies. The combination of this characterization with chemometric tools allows the classification of Italian apples based on their origin both on a national and regional scale. This approach represents an interesting tool to enhance and protect PDO and PGI Italian products. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

As one of the largest volume flavor ingredients, vanillin remains an attractive target for development of a cost-effective and sustainable process to manufacture. Presented here is newly available data on the production of vanillin via fermentation in an engineered strain of Saccharomyces cerevisiae grown on sucrose ex-sugarcane. The use of the C4 plant source of carbohydrate resulted in a δ13C mean stable isotope ratio of -14.43 ‰ (SD = 0.24) relative to the V-PDB standard and a δ2H mean stable isotope ratio of -122.8 ‰ (SD = 2.9) relative to the SMOW standard by IRMS. The abundance of 14C in the fermentation derived vanillin averaged 14.01 dpm/gC (SD = 0.09) by AMS measurement. These data are compared to historical data collected on vanillin derived from a number of sources to provide a more holistic view on vanillin bulk isotope data based on its method of manufacture., Vanilla, Vanillin, Isotope ratio, δ13C, δ2H.

Resonance ionization mass spectrometry is an ultra-sensitive and highly element selective tool for spectroscopy, ionization and detection of atoms and thus enables rare isotope determination. In combination with spatially resolved sputtering of neutrals by an initial ion beam, e.g. within a commercial secondary ion mass spectrometer, an isotope and isobar selective analysis technique with resolution on the micrometer scale for particles and surfaces is realized. Detection of minuscule amounts of specific actinides, e.g. of plutonium, in environmental and technical samples by this ultra-trace analysis technique requires detailed knowledge about the atomic physics of the element. Identification and characterization of the specific resonance ionization scheme applied within the particular geometry of the apparatus in use is needed. An analysis of the dependence of the specifications, specifically regarding the influence of the relative laser beam polarizations is presented here as an aspect, that could have a severe impact on isotope ratio precision and overall efficiency in the resulting ion signal.

The capabilities of Cu isotope ratio measurements are often restricted by the small volumes of sample available and/or their low Cu concentration. In this work, an analytical approach was developed for performing Cu isotopic analysis via multi-collector ICP-mass spectrometry (MC-ICP-MS) at ultra-trace level using Ga as an internal standard for mass bias correction. The minimum concentration of Cu required for accurate and precise isotope ratio measurements was established to be 20 mu g L-1 with wet plasma conditions and 5 mu g L-1 with dry plasma conditions. The use of Ga as an internal standard for mass bias correction provided several advantages compared to Ni, i.e. improved internal precision on delta Cu-65 values and lower blank levels. Ga can also be used at a 4- fold lower concentration level than Ni. However, in wet plasma conditions, the signals of (ArO2H+)-Ar-36-O-16-H-1 and (ArNO+)-Ar-40-N-15-O-16 interfered with the signals of Ga-69(+) and Ga-71(+), respectively, while in dry plasma conditions, realized by the use of a desolvation unit, Ga-69(+) suffered from spectral interference from (ArN2H+)-Ar-40-N-14-H-1. These interferences were resolved by using medium mass resolution. For validation purposes, the approach was applied to commercially available blood and serum samples. The delta Cu-65 values for the samples measured at a concentration level of 5 mu g L-1 Cu and 5 mu g L-1 Ga using dry plasma conditions were in good agreement with those obtained for isotope ratio measurements at the "standard" concentration level of 200 mu g L-1 Cu and 200 mu g L-1 Ni using wet plasma conditions. In addition, the delta Cu-65 values obtained for micro-samples of serum/blood (volume of 100 mu L) were in good agreement with the corresponding ones obtained using the "standard" volume for isotopic analysis (500 mu L).

In this study, stable isotope signatures (δ13C, δ15N, and δD) of both tea leaves and tea infusions were investigated to identify the geographical origin of Turkish domestic and imported tea samples. Sixteen domestic tea samples collected from different locations in the Black Sea Region, which produces almost 100% of tea in Turkey, and 11 imported tea samples (Kenya, India, Sri Lanka, Indonesia, and China) purchased from importers were studied. δ13C, δ15N, and δD in the samples were determined using isotope ratio mass spectrometry (IR-MS). δ13C in the samples ranged from −29.18 ± 0.01 to −25.7 ± 0.2, while δ15N ranged between 1.1 ± 0.2 and 5.2 ± 0.8. However, δD in the samples were found to be in the range from 56.5 ± 0.3 to 72 ± 1. The classifications of the tea samples into domestic and imported tea samples were achieved with 100% accuracy using multivariate statistical analyses (principal component analysis, PCA, and hierarchical cluster analysis, HCA). In conclusion, the domestic tea samples had a distinctive isotopic fingerprint and the isotopic ratios used in the study can be significant predictors in determination of the geographical source of Turkish tea.

In this study, we report the first independent measurements of lutetium isotopic composition using multi-collector ICPMS in four commercial lutetium materials, including a new NRC candidate lutetium isotopic reference material, LUIS-1. The regression model was used to correct for the instrumental isotopic fractionation (mass bias) using NIST SRM 989 isotopic rhenium as the primary calibrator. The regression model is based on a short 15-min measurement sessions at varying ICP plasma power. Isotope ratio of R176/175 = 0.026553(11)k = 1, corresponding isotopic abundances of x176 = 0.025866(11)k = 1, x175 = 0.974134(11)k = 1, and an atomic weight of Ar(Lu) = 174.966693(13)k = 1 were obtained for lutetium in LUIS-1. Uncertainty estimation was performed using a mixture of modeling approaches in accordance with the JCGM 100:2008 “Guide to the Expression of Uncertainty in Measurement” and its Supplement 1. The relative contribution of the rhenium primary standard to the combined uncertainty of 176Lu/175Lu isotope ratio was 15%.

Submitted by Pedro Silva Filho (pfsilva@ipen.br) on 2019-06-21T18:01:20Z No. of bitstreams: 0 Made available in DSpace on 2019-06-21T18:01:20Z (GMT). No. of bitstreams: 0 Modelos experimentais de c??ncer de pr??stata demonstraram n??veis aumentados de protoporfirina IX (PpIX) no sangue e nas fezes de camundongos, fazendo com que a quantifica????o dessa mol??cula pudesse ser aventada para a identifica????o desse tipo de tumor. Nesse estudo do tipo caso-controle, a autofluoresc??ncia de porfirinas em fezes humanas foi analisada usando espectroscopia de fluoresc??ncia em pacientes com c??ncer de pr??stata e controles. Dados sociodemogr??ficos, amostras sangu??neas para determina????o dos n??veis de PSA (ant??geno prost??tico espec??fico) e amostras de fezes para quantifica????o de porfirinas foram obtidas ap??s consentimento dos pacientes. Recrutaram-se 18 pacientes em amostra calculada a partir dos estudos de refer??ncia. Realizou-se varredura para encontrar o melhor pico espectrofotom??trico a partir de diversas dilui????es acetona/fezes. Primeiramente, 3 mililitros de acetona de grau anal??tico foram adicionados a 0,3 gramas de fezes e a mistura foi macerada e centrifugada a 4.000 rota????es por minuto durante 15 minutos. O sobrenadante foi analisado espectroscopicamente. Os espectros de emiss??o a 550-750 nm foram obtidos excitando as amostras a 405 nm. Vari??veis sociodemogr??ficas foram analisadas e evidenciaram homogeneidade entre os grupos estudados. Um contraste significativo entre as amostras de indiv??duos normais e oncol??gicos foi estabelecido na regi??o espectral de 670-675 nm (p = 0,000127), o que corresponde a um aumento significativo de porfirinas fecais em pacientes com c??ncer. N??o houve correla????o estatisticamente significativa entre os n??veis de PSA e as porfirinas fecais (R = -0,0221). Neste estudo preliminar realizado em seres humanos, os resultados mostram um m??todo simples e n??o invasivo para avaliar as porfirinas fecais, que t??m o potencial de funcionar como um biomarcador tumoral em pacientes com c??ncer de pr??stata. Essa abordagem poderia aumentar a sensibilidade e a especificidade do teste de PSA. Tese (Doutorado em Tecnologia Nuclear) IPEN/T Instituto de Pesquisas Energ??ticas e Nucleares - IPEN-CNEN/SP

A diffusive gradient in thin films (DGT) technique, based on a strongly basic anion exchange resin (Amberlite IRA-400), was successfully tested for 34S/32S analysis in labile soil sulfate. Separation of matrix elements (Na, K, and Ca) that potentially cause non-spectral interferences in 34S/32S analysis by MC ICP-MS (multi-collector inductively coupled plasma–mass spectrometry) during sampling of sulfate was demonstrated. No isotopic fractionation caused by diffusion or elution of sulfate was observed below a resin gel disc loading of ≤79 μg S. Above this threshold, fractionation towards 34S was observed. The method was applied to 11 different topsoils and one mineral soil profile (0–100 cm depth) and compared with soil sulfate extraction by water. The S amount and isotopic ratio in DGT-S and water-extractable sulfate correlated significantly (r 2 = 0.89 and r 2 = 0.74 for the 11 topsoils, respectively). The systematically lower 34S/32S isotope ratios of the DGT-S were ascribed to mineralization of organic S.

Introduction: Hepatoblastoma is the most common primary liver tumor in children. However, it occurs rarely, with an incidence of 0.5-1.5 cases per million children. There is no clear explanation of the relationship between clinicopathologic features, therapy, and outcome in hepatoblastoma cases, so far. One of the most widely accepted prognostic factors in hepatoblastoma is histology of the tumor. The aim of the study was to determine the potential differences in biology of hepatoblastoma histological subtypes at the atomic level using the unique method of isotope ratio mass spectrometry, which is especially valuable in examination of small groups of biological samples. Material/Methods: Twenty-four measurements of nitrogen stable isotope ratio, carbon stable isotope ratio and total carbon to nitrogen mass ratio in fetal and embryonal hepatoblastoma tissue were performed using a Sercon 20-22 Continuous Flow Isotope Ratio Mass Spectrometer (CF-IRMS) coupled with a Sercon SL elemental analyzer for simultaneous carbon-nitrogen-sulfur (NCS) analysis. Results: A difference of about 1.781 parts per thousand in stable nitrogen isotope N-15/N-14 ratio was found between examined hepatoblastoma histological subtypes. Conclusions: The prognosis in liver tumors cases in children may be challenging particularly because of the lack of versatile methods of its evaluation. Isotope ratio mass spectrometry allows one to determine the difference between hepatoblastoma histological subtypes and clearly indicates the cases with the best outcome.

Forensic application of carbon isotope ratio measurements of honey and honey protein to investigate the degree of adulteration with high fructose corn syrup or other C4 plant sugars is well established. These measurements must use methods that exhibit suitable performance criteria, particularly with regard to measurement uncertainty and traceability – low levels of adulteration can only be detected by methods that result in suitably small measurement uncertainties such that differences of 1‰ or less can be reliably detected. Inter-laboratory exercises are invaluable to assess the state-of-the art of measurement capabilities of laboratories necessary to achieve such performance criteria. National and designated metrology institutes from a number of countries recently participated in an inter-laboratory assessment (CCQM-K140) of stable carbon isotope ratio determination of bulk honey. The same sample material was distributed to a number of forensic isotope analysis laboratories that could not participate directly in the metrological comparison. The results from these studies have demonstrated that the majority of participants provided isotope delta values with acceptable performance metrics; that all participants ensured traceability of their results; and that where measurement uncertainties were reported; these were fit-for-purpose. A number of the forensic laboratories only reported precision rather than full estimates of measurement uncertainty and this was the major cause of the few instances of questionable performance metrics. Reporting of standard deviations in place of measurement uncertainties is common practice outside metrology institutes and the implications for interpretations of small differences in isotopic compositions are discussed. The results have also highlighted a number of considerations that are useful for organisers of similar inter-laboratory studies in the future.

ICP-MS has played a key role in inorganic chemical metrology for 25 years, from the 1993 CIPM feasibility study which led to establishment of the CCQM. Since that time, the Inorganic Analysis Working Group of the CCQM has organised 56 international comparisons involving measurements by ICP-MS and, in a recent comparison, 16 different national institutes submitted their results using the technique. Metrological applications of ICP-MS currently address an enormous range of measurements using a wide variety of instrumentation, calibration strategies and methodologies. This review provides an overview of the ICP-MS field with an emphasis on developments which are of particular relevance to chemical metrology. Examples from CCQM comparisons and the services available from the participants are used to illustrate how the capability and scope of ICP-MS methods have expanded far beyond the expectations of 1993. This is due in part to the research and development Programmes of the national institutes which participate in the CCQM. They have played a key role in advancing new instrumentation and applications for elemental analysis, isotope dilution mass spectrometry, determination of isotopic ratio or composition, and speciation of organometallic compounds. These developments are continuing today, as demonstrated by work in new fields such as heteroatom quantitation of proteins, characterisation and counting of nanoparticles using spICP-MS, and LA-ICP-MS analysis of solid materials.

Thermal ionization mass spectrometry (TIMS) is a well established instrumental technique for providing accurate and precise isotope ratio measurements for elements with low first ionization potential. In the nuclear domain, particularly for the study of spent nuclear fuel sample solutions, the reduction of quantities is an important issue in order to decrease the analyst exposition to the radioactive samples. This paper presents experimental results obtained for picogram quantities of samples using electron multipliers (Channeltrons) implanted on the new generation of TIMS associated with the total evaporation (TE) acquisition method. TE method presents some advantages for the measurement of low quantities of samples in relation to the whole sample consumption and the integration of the whole signal. For this study, a Thermal Ionization Mass Spectrometer from IsotopX (Isoprobe-T) equipped with a multi-collector system including Faraday cups and four movable Channeltrons is used. This work is focused on lanthanide elements, and particularly europium, in relation to the importance of their characterization in the spent fuel to validate neutronic calculation codes. In a first approach, europium isotopic ratios by total evaporation method using Faraday cups are obtained for quantities down to 250 pg. The results obtained by TE (Faraday cups only) on such low quantities confirm the potentialities of the method. A reproducibility of 2.5‰ (k = 2), was obtained on the 153Eu/151Eu ratio (n = 11), for natural samples with an accuracy around 1‰. In a second approach the same procedure is tested on Channeltron detectors by reducing the amounts of samples (from 50 pg to 1 pg). In order to obtain accurate isotope results, intrinsic parameters such as applied voltages, dead time and noise were determined. A Channeltron specific intercalibration gain method was also developed, as this parameter was found to be the major source of uncertainties using this type of detectors. The reproducibility on the 153Eu/151Eu ratio was respectively found around 3% (k = 2). These results show the potentialities of isotopic measurements of sub-nanograms quantities and the different sources of uncertainties using total evaporation and Channeltrons on the Isoprobe-T.

An isotope ratio imaging technique using the HokuDai isotope microscope system has been applied to in situ survey for presolar grains in the type-3 enstatite chondrite ALHA81189. Rastered and static ion beam were used for primary beam. Lateral resolution of the isotope image was achieved to be 0.4 μm for static ion beam mode and to be 0.6 μm for rastered ion beam mode. As a result, the abundances of presolar grains are 150–200% larger under the static ion beam mode than under the rastered ion beam mode. Development of image processing introducing isotopography of 32 S − , 24 Mg 16 O − and 56 Fe − succeeded to increase efficiency of presolar grain characterization. Using the static ion beam and introducing appropriate isotopography were very useful methods of in situ characterization of presolar grains in meteorites.

The unique capabilities of multiple collector inductively coupled mass spectrometry (MC-ICP-MS) for high precision isotope ratio measurements in light elements as Li, Mg, Ca, and Cu are reviewed in this paper. These elements have been intensively studied at the Geological Survey of Israel (GSI) and other laboratories over the past few years, and the methods used to obtain high precision isotope analyses are discussed in detail. The scientific study of isotopic fractionation of these elements is significant for achieving a better understanding of geochemical and biochemical processes in nature and the environment.

9 pages, 5 figures, 2 tables.-- Issue title: TSOP 2005 - Papers from the 22nd Annual Meeting of TSOP (Louisville, Kentucky, USA, Sep 11-15, 2005)., Lead isotope ratios in coals of different rank from several Spanish basins were estimated and related with their characteristics. The isotope Pb-206/Pb-207 ratio values of the coals studied range between 1.13 and 1.21, with the exception of some coal samples from the Cretaceous which are more radiogenic. Coals were classified into groups according to their lead isotope ratios. These in turn were related to the isotope ratios of the minerals galena, pyrite, chalcopyrite, and carbonates. Some of the low-rank coals, in which lead might be expected to be associated with the organic matter, were not found to be related with the isotope ratios of minerals. The isotope ratios of the individual densimetric fractions separated from a bituminous coal are different to those of the raw coal. The differences between these isotope ratios may not only be due to the diverse origin of lead in different coals, but also with the possible presence of several lead species incorporated from various sources in a particular coal. The results of this work represent an important contribution to the lead isotope ratio database essential for the accurate interpretation of data regarding pollution sources.

A amostragem ambiental por esfregaço ou swipe samples é uma metodologia que vem sendo empregada rotineiramente pela Agência Internacional de Energia Atômica (AIEA) para verificar se os Estados signatários do Acordo de Salvaguardas estão realizando atividades nucleares não declaradas. A análise dessas amostras ambientais é complementar aos procedimentos de salvaguardas convencionais para a verificação das informações cedidas pelos Estados. Neste trabalho, foi descrita uma metodologia que visa a fortalecer os processos de salvaguarda nuclear e da ciência forense nuclear no país. A proposta é estudar e avaliar a técnica de ablação à laser acoplada a um espectrômetro de massa de alta resolução com fonte de plasma indutivamente acoplado (LA-HR-ICP-MS Laser Ablation High Resolution Inductively Coupled Plasma Mass Spectrometry), como técnica alternativa para a análise das amostras de esfregaço. Adicionalmente, foram empregadas outras técnicas complementares (atividade radioativa, microscopia eletrônica de varredura e espectroscopia de energia dispersiva) com o intuito de garantir maior segurança ao processo de inspeção de salvaguardas e investigações forenses nucleares. A precisão, medida através do desvio padrão relativo (DPR),dos resultados obtidos para as razões isotópicas 234U/238U, 235U/238U e 236U/238U do padrão analisado (CRM -125A) para a medida do fator de discriminação de massa foram, respectivamente, 1,3 %, 0,2 % e 7,6 %. Já as incertezas percentuais (u %), que também contemplam o DPR das medições, variaram de 3,5 % a 29,8 % para as medições da razão isotópica 235U/238U e de 16,6 % a 42,9 % para a razão isotópica 234U/238U. Esses valores mostraram-se compatíveis com outros estudos que utilizaram a mesma técnica para análise de amostras reais coletadas em uma instalação nuclear. As amostras coletadas apresentaram nível de enriquecimento que variou de (2,3 ± 0,7) % (amostra 3 corredor de acesso à instalação) a (17,3 ± 2,8) % (amostra 18 bancada de recuperação de UF4). A partir da coleta de amostras nesses diversos pontos, desde a entrada da instalação até a bancada em que se manuseia o urânio enriquecido, foi possível detectar diversos níveis de enriquecimento no isótopo 235U. Environmental sampling performed by means of swipe samples is a methodology frequently employed by International Atomic Energy Agency (IAEA) to verify if the signatory States of the Safeguards Agreements are conducing unauthorized activities. Swipe samples analysis is complementary to the Safeguards ordinary procedures used to verify the information given by the States. In this work it was described a methodology intending to strengthen the nuclear safeguards and nuclear forensics procedures. The proposal is to study and evaluate the laser ablation high resolution inductively coupled plasma mass spectrometry (LA-HR-ICP-MS) technique as an alternative to analyze the real-life swipe samples. The precision achieved through the standard(CRM -125A)measurements, represented by the relative standard deviation (RSD), was respectively 1.3 %, 0.2 % e 7.6 %for the 234U/238U, 235U/238U e 236U/238Uisotopes ratios. The percent uncertainties (u %), which covers the RSD, ranged from 3.5 % to 29.8 % to the 235U/238U measurements and from 16.6 % to 42.9 % to the 234U/238U isotope ratio. These results were compatible with former studies performed by the LA-HR-ICP-MS that analyzed real-life swipe samples collected at a nuclear facility. Swipe samples collected from several points of the nuclear facility presented enrichment level ranging from (2.3 ± 0.7) % (sample 3) to (17.3 ± 2.8) % (sample18). They also allowed detecting different enrichment levels within the facility.

Helium, neon and argon isotope ratios have been analysed from phenocrysts of eleven lava samples belonging to the last eruptive cycle of Mount Vesuvius (1631 until 1944). The phenocrysts separates include pyroxene (N = 10) and olivine (N = 1). All phenocryst samples show similarly low gas contents (He, Ne and Ar ~10-10 cm3/g). 3He/4He ratios, 5.3-2.11 R(a), are generally low if compared to those typical of the MORB and those of the European Subcontinental Mantle (ESCM), respectively R/R(a) 8.5 ± 1 and 6.0-6.5. A decreasing trend is found from 1631 to 1796, while a more homogeneous set of data is obtained for more recent eruptions, as evidenced by an average R/R(a) value of 2.85. Neon ratios (21Ne/22Ne and 20Ne/22Ne) strongly differ from those typically found on volcanoes and suggest that a crustal component has been added in the source region to Mt. Vesuvius magmas. Argon ratios (40Ar/36Ar and 38Ar/36Ar) have values similar to the atmosphere and are well correlated. The low 40Ar/36Ar ratio (max. 302) is, however, in the range of the 40Ar/36Ar ratios obtained from several lava samples at other Italian volcanoes and might be considered to have a deep origin. Two hypothesis have been discussed: (1) a deep argon-like-air source, due to subduction of air-rich sediments and/or (2) a preferential loss of Ar, in comparison to lighter noble gases, from silicic melts. Helium isotopic analysis of gas samples recently collected from crater and submarine fumaroles are similar to those of lavas belonging to the final part of this eruptive cycle. This result supports the idea that no new juvenile fluids from the source region have been injected into the magmatic reservoir during the 1631-1944 eruptive cycle and, more importantly, until 1993. Both sets of data help to understand the genesis of these fluids and to constrain the current activity of the volcano.

Forensic Sci.Int. ISI Document Delivery No.: 844PF Times Cited: 11 Cited Reference Count: 43 Boccard, Julien Badoud, Flavia Grata, Elia Ouertani, Samia Hanafi, Mohamed Mazerolles, Gerard Lanteri, Pierre Veuthey, Jean-Luc Saugy, Martial Rudaz, Serge Elsevier ireland ltd Clare; International audience; Anti-doping authorities have high expectations of the athlete steroidal passport (ASP) for anabolic-androgenic steroids misuse detection. However, it is still limited to the monitoring of known well-established compounds and might greatly benefit from the discovery of new relevant biomarkers candidates. In this context, steroidomics opens the way to the untargeted simultaneous evaluation of a high number of compounds. Analytical platforms associating the performance of ultra-high pressure liquid chromatography (UHPLC) and the high mass-resolving power of quadrupole time-of-flight (QTOF) mass spectrometers are particularly adapted for such purpose. An untargeted steroidomic approach was proposed to analyse urine samples from a clinical trial for the discovery of relevant biomarkers of testosterone undecanoate oral intake. Automatic peak detection was performed and a filter of reference steroid metabolites mass-to-charge ratio (m/z) values was applied to the raw data to ensure the selection of a subset of steroid-related features. Chemometric tools were applied for the filtering and the analysis of UHPLC-QTOF-MS(E) data. Time kinetics could be assessed with N-way projections to latent structures discriminant analysis (N-PLS-DA) and a detection window was confirmed. Orthogonal projections to latent structures discriminant analysis (O-PLS-DA) classification models were evaluated in a second step to assess the predictive power of both known metabolites and unknown compounds. A shared and unique structure plot (SUS-plot) analysis was performed to select the most promising unknown candidates and receiver operating characteristic (ROC) curves were computed to assess specificity criteria applied in routine doping control. This approach underlined the pertinence to monitor both glucuronide and sulphate steroid conjugates and include them in the athletes passport, while promising biomarkers were also highlighted.

In this short review we describe recent new observations of millimetre transitions of molecules in selected regions of the Magellanic Clouds. The observations were made using the Swedish-ESO Submillimetre Telescope, SEST, (Booth et al. 1989), the relatively high resolution of which facilitates, for the first time, observations of individual giant molecular clouds in the Magellanic Clouds. We have mapped the distribution of the emission from the two lowest rotational transitions of 12CO and 13CO and hence have derived excitation conditions for the molecule. In addition, we have observed several well-known interstellar molecules in the same regions, thus doubling the number of known molecules in the Large Magellanic Cloud (LMC). The fact that all the observations have been made under controlled conditions with the same telescope enables a reasonable intercomparison of the molecular column densities. In particular, we are able to observe the relative abundances among the different isotopically substituted species of CO.

To develop further our understanding of initial dietary copper metabolism, a method has been developed to separate plasma copper that is bound to albumin, from that bound to ceruloplasmin. This method has been tested using plasma samples from a pilot study involving six human volunteers who consumed 3mg oral doses of the stable isotope (65)Cu and gave blood samples at timed intervals up to 7 days. The results suggest that this method can be used to monitor dynamic fluctuations in newly absorbed copper over a short time frame.

Made available in DSpace on 2014-10-09T12:51:55Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T14:08:15Z (GMT). No. of bitstreams: 0 Este trabalho descreve a prepara????o, caracteriza????o e certifica????o de um conjunto de materiais de refer??ncia isot??picos de ur??nio na faixa de 0,5 a 20,0 % de 235U em massa. Os principais conceitos da metrologia em medi????es qu??micas foram aplicados para que as propriedades certificadas nos materiais pudessem ser rastre??veis diretamente ao Sistema Internacional de Unidades (SI). Em conseq????ncia desta abordagem, estes materiais poder??o ser utilizados na calibra????o de instrumentos de medi????o, avalia????o da incerteza de medi????o, valida????o de m??todos anal??ticos, avalia????o da performance de analistas, rotinas de controle de qualidade e em programas de intercompara????o de resultados de medi????o. As mais avan??adas t??cnicas e m??todos de espectrometria de massas, a saber, espectrometria de massas com fonte de g??s (GSMS), espectrometria de massas por termoionizac??o (TIMS) e espectrometria de massas com fonte de plasma induzido (ICPMS) foram investigadas para identificar quais s??o os componentes dominantes na incerteza e quantificar a sua contribui????o no valor final da incerteza de medi????o da raz??o isot??pica. Os resultados obtidos foram comparados entre si, para verificar quais t??cnicas e m??todos est??o associados aos menores valores de incerteza de medi????o. A raz??o isot??pica n(235U)/n(238U) nos materiais produzidos foi certificada com incertezas de medi????o expandidas na faixa de 0,02 a 0,10 % e as raz??es n(234U)/n(238U) e n(236U)/n(238U), com incertezas na faixa de 0,03 a 2,20 %. Estes valores atendem plenamente aos requisitos da caracteriza????o isot??pica do combust??vel nuclear, bem como aos requisitos das an??lises de amostras ambientais para fins de salvaguardas nucleares. Tese (Doutoramento) IPEN/T Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

During microbial breakdown of leaf litter a fraction of the C lost by the litter is not released to the atmosphere as CO(2) but remains in the soil as microbial byproducts. The amount of this fraction and the factors influencing its size are not yet clearly known. We performed a laboratory experiment to quantify the flow of C from decaying litter into the soil, by means of stable C isotopes, and tested its dependence on litter chemical properties. Three sets of (13)C-depleted leaf litter (Liquidambar styraciflua L., Cercis canadensis L. and Pinus taeda L.) were incubated in the laboratory in jars containing (13)C-enriched soil (i.e. formed C4 vegetation). Four jars containing soil only were used as a control. Litter chemical properties were measured using thermogravimetry (Tg) and pyrolysis-gas chromatography/mass spectrometry-combustion interface-isotope ratio mass spectrometry (Py-GC/MS-C-IRMS). The respiration rates and the delta(13)C of the respired CO(2) were measured at regular intervals. After 8 months of incubation, soils incubated with both L. styraciflua and C. canadensis showed a significant change in delta(13)C (delta(13)C(final) = -20.2 +/- 0.4 per thousand and -19.5 +/- 0.5 per thousand, respectively) with respect to the initial value (delta(13)C(initial) = -17.7 +/- 0.3 per thousand); the same did not hold for soil incubated with P. taeda (delta(13)C(final:)-18.1 +/- 0.5 per thousand). The percentages of litter-derived C in soil over the total C loss were not statistically different from one litter species to another. This suggests that there is no dependence of the percentage of C input into the soil (over the total C loss) on litter quality and that the fractional loss of leaf litter C is dependent only on the microbial assimilation efficiency. The percentage of litter-derived C in soil was estimated to be 13 +/- 3% of total C loss.

Made available in DSpace on 2014-10-09T12:51:01Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T13:59:15Z (GMT). No. of bitstreams: 1 11135.pdf: 7189578 bytes, checksum: 2301b9d209a5d40ecb7cb637fe73b0f8 (MD5) Tese (Doutoramento) IPEN/T Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:44:24Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T13:57:23Z (GMT). No. of bitstreams: 1 06890.pdf: 3271433 bytes, checksum: 57399ce5f630231a9b2741455ed096f0 (MD5) Dissertacao (Mestrado) IPEN/D Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:44:34Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T13:57:11Z (GMT). No. of bitstreams: 1 06861.pdf: 8656275 bytes, checksum: 33d75be9bc7f27a315785b762567f56c (MD5) Tese (Doutoramento) IPEN/T Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:36:27Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T13:59:26Z (GMT). No. of bitstreams: 1 03875.pdf: 1641198 bytes, checksum: aa054234bd30c0adc370774ed47847d3 (MD5) Dissertacao (Mestrado) IPEN/D Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:36:16Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T13:59:20Z (GMT). No. of bitstreams: 1 03766.pdf: 3809732 bytes, checksum: 161cbf8550f80b76813606d7f8abf4de (MD5) Tese (Doutoramento) IPEN/T Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:28:35Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T13:56:02Z (GMT). No. of bitstreams: 0 Tese (Doutoramento) IEA/T Universidade Karlsruhe, Alemanha

Made available in DSpace on 2014-10-09T12:31:40Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T14:00:33Z (GMT). No. of bitstreams: 1 02283.pdf: 2071398 bytes, checksum: 8e4ed5e58aa3dd0625d4c73e2fb0d2a5 (MD5) Tese (Doutoramento) IPEN/T Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:30:50Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T14:06:15Z (GMT). No. of bitstreams: 1 01365.pdf: 962669 bytes, checksum: e02b455c6b91c9ff1df7371c13f0e5fb (MD5) Dissertacao (Mestrado) IPEN/D Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:30:41Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T14:00:38Z (GMT). No. of bitstreams: 1 01293.pdf: 1218457 bytes, checksum: 4fc6334de8505695e9783162eebf4a08 (MD5) Dissertacao (Mestrado) IEA/D Instituto de Energia Atomica - IEA

Made available in DSpace on 2014-10-09T12:50:42Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T13:59:03Z (GMT). No. of bitstreams: 1 00385.pdf: 917455 bytes, checksum: 170691f120f1bd5b66fa48cba02fe1f6 (MD5) Dissertacao (Mestrado) IEA/D Escola Politecnica, Universidade de Sao Paulo - POLI/USP

Made available in DSpace on 2014-10-09T12:30:05Z (GMT). No. of bitstreams: 0 Made available in DSpace on 2014-10-09T14:04:20Z (GMT). No. of bitstreams: 1 00488.pdf: 1307796 bytes, checksum: ff2c814dc265e2504b4039389b1fa1f7 (MD5) Dissertacao (Mestrado) IEA/D Instituto de Energia Atomica - IEA