Добірка наукової літератури з теми "Mc-Icpms / icpms"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Mc-Icpms / icpms".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Статті в журналах з теми "Mc-Icpms / icpms"
1
Douthitt, C. B. "The evolution and applications of multicollector ICPMS (MC-ICPMS)." Analytical and Bioanalytical Chemistry 390, no. 2 (October 16, 2007): 437–40. http://dx.doi.org/10.1007/s00216-007-1660-x.
Повний текст джерела
2
Douthitt, Charles B. "Commercial development of HR-ICPMS, MC-ICPMS and HR-GDMS." Journal of Analytical Atomic Spectrometry 23, no. 5 (2008): 685. http://dx.doi.org/10.1039/b800341f.
Повний текст джерела
3
Gourgiotis, Alkiviadis, Sylvain Bérail, Pascale Louvat, Hélène Isnard, Julien Moureau, Anthony Nonell, Gérard Manhès, et al. "Method for isotope ratio drift correction by internal amplifier signal synchronization in MC-ICPMS transient signals." J. Anal. At. Spectrom. 29, no. 9 (2014): 1607–17. http://dx.doi.org/10.1039/c4ja00118d.
Повний текст джерела
4
Martelat, Benoît, Laurent Vio, Hélène Isnard, Jérôme Simonnet, Térence Cornet, Anthony Nonell, and Frédéric Chartier. "Neodymium isotope ratio measurements by CE-MC-ICPMS: investigation of isotopic fractionation and evaluation of analytical performances." Journal of Analytical Atomic Spectrometry 32, no. 11 (2017): 2271–80. http://dx.doi.org/10.1039/c7ja00250e.
Повний текст джерела
5
Wu, Li, Ling, Yang, Li, Li, Mao, Li, and Putlitz. "Further Characterization of the RW-1 Monazite: A New Working Reference Material for Oxygen and Neodymium Isotopic Microanalysis." Minerals 9, no. 10 (September 26, 2019): 583. http://dx.doi.org/10.3390/min9100583.
Повний текст джерелаАнотація:
The oxygen (O) and neodymium (Nd) isotopic composition of monazite provides an ideal tracer of metamorphism and hydrothermal activity. Calibration of the matrix effect and monitoring of the external precision of monazite O–Nd isotopes with microbeam techniques, such as secondary ion mass spectrometry (SIMS) and laser ablation-multicollector-inductively coupled plasma-mass spectrometry (LA-MC-ICPMS), require well-characterized natural monazite standards for precise microbeam measurements. However, the limited number of standards available is impeding the application of monazite O–Nd isotopes. Here, we report on the RW-1 monazite as a potential new working reference material for microbeam analysis of O–Nd isotopes. Microbeam measurements by electron probe microanalysis (EPMA), SIMS, and LA-MC-ICPMS at 10–24 µm scales have confirmed that it is homogeneous in both elemental and O–Nd isotopic compositions. SIMS measurements yield δ18O values consistent, within errors, with those obtained by laser fluorination techniques. Precise analyses of Nd isotope by thermal ionization mass spectrometry (TIMS) are consistent with mean results of LA-MC-ICPMS analyses. We recommend δ18O = 6.30‰ ± 0.16‰ (2SD) and 143Nd/144Nd = 0.512282 ± 0.000011 (2SD) as being the reference values for the RW-1 monazite.
6
Obert, J. Christina, Denis Scholz, Jörg Lippold, Thomas Felis, Klaus Peter Jochum, and Meinrat O. Andreae. "Chemical separation and MC-ICPMS analysis of U, Th, Pa and Ra isotope ratios of carbonates." Journal of Analytical Atomic Spectrometry 33, no. 8 (2018): 1372–83. http://dx.doi.org/10.1039/c7ja00431a.
Повний текст джерела
7
Malinovsky, Dmitry, Philip J. H. Dunn, and Heidi Goenaga-Infante. "Calibration of Mo isotope amount ratio measurements by MC-ICPMS using normalisation to an internal standard and improved experimental design." Journal of Analytical Atomic Spectrometry 31, no. 10 (2016): 1978–88. http://dx.doi.org/10.1039/c6ja00184j.
Повний текст джерела
8
Gourgiotis, Alkiviadis, Gérard Manhès, Benoît Martelat, and Hélène Isnard. "Deconvolution of the isotopic drift in LC-MC-ICPMS coupling: a new tool for studying isotope fractionation induced by sample introduction techniques." Journal of Analytical Atomic Spectrometry 32, no. 7 (2017): 1428–34. http://dx.doi.org/10.1039/c6ja00418k.
Повний текст джерела
9
Abraham, Kathrin, Jane Barling, Christopher Siebert, Nick Belshaw, Louise Gall, and Alex N. Halliday. "Determination of mass-dependent variations in tungsten stable isotope compositions of geological reference materials by double-spike and MC-ICPMS." Journal of Analytical Atomic Spectrometry 30, no. 11 (2015): 2334–42. http://dx.doi.org/10.1039/c5ja00210a.
Повний текст джерела
10
Zakon, Yevgeni, Ludwik Halicz та Faina Gelman. "δ 13C compound-specific isotope analysis in organic compounds by GC/MC-ICPMS". Journal of Analytical Atomic Spectrometry 36, № 9 (2021): 1884–88. http://dx.doi.org/10.1039/d1ja00096a.
Повний текст джерелаДисертації з теми "Mc-Icpms / icpms"
1
Martelat, Benoît. "Développement d'une méthode électrophorétique de séparation de l'uranium, du plutonium et des lanthanides et couplage avec un ICPMS-MC pour l'acquisition de rapports isotopiques." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066447/document.
Повний текст джерелаАнотація:
La caractérisation isotopique des éléments présents dans les combustibles nucléaires irradiés est d'une importance majeure pour la qualification et la validation des codes de calculs neutroniques ainsi que la gestion des déchets nucléaires. Le protocole conventionnel pour l'analyse de ces échantillons nécessite plusieurs étapes de séparation par chromatographie liquide. L'uranium (U), le plutonium (Pu) et une fraction contenant les produits de fission et les actinides mineurs, sont séparés par chromatographie sur résine échangeuse d'ions puis les fractions purifiées d'U et de Pu sont analysées par spectrométrie de masse. L'objectif de cette thèse consiste à étudier et développer un protocole analytique applicable sur des échantillons de type combustibles irradiés et employant une technique séparative transposable sur plateforme miniaturisée qui devra pouvoir être couplée à un spectromètre de masse à source plasma et à système multicollection (ICPMS-MC) afin de réaliser en ligne l'analyse isotopique et élémentaire des éléments présents dans le combustible irradié. Une méthode de séparation de l'U, du thorium (Th) et des lanthanides par électrophorèse capillaire (EC) avec préconcentration de l'échantillon a été développée en utilisant le Th(IV) comme analogue chimique du Pu(IV). L'électrolyte de séparation se compose d'acide acétique 0,25M comme complexant ainsi que de sel d'ammonium 0,1M, pour ajuster la force ionique et permettre la préconcentration. Le montage d'EC a été adapté afin d'être intégré en boite à gants et couplé à un ICPMS-MC. La séparation de l'Am de l'U et du Pu a été réalisée sur quelques nL d'une solution de combustible irradiéPrecise isotopic and elemental characterization of nuclear spent fuel is a major concern for the validation of the neutronic calculation codes and waste management in the nuclear industry. The conventional protocol for the analysis of nuclear fuel samples uses several purification steps by liquid chromatography. Uranium (U) and plutonium (Pu) and a fraction containing fission products and minor actinides are separated using ion exchange chromatography prior to the isotopic characterization of the U and Pu fractions by multi-collector mass spectrometry techniques. The objective of the work presented is to develop a new analytical approach based on miniaturized separation techniques like capillary and microfluidic electrophoresis coupled with a multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) detection for online isotopic ratio measurements. An electrophoretic separation method of U, Pu and fission products with a stacking step was developed using thorium (Th) as a chemical analog for Pu(IV). The separation electrolyte is composed of acetic acid (0.25M) as complexing agent for the separation and 0.1M of ammonium salt to realize the stacking step. The instrumentation was adapted to be used in glove box and directly coupled to a MC-ICPMS. The separation of Am, Pu and U was realized with few nL of a spent nuclear fuel solution. The reproducibilities obtained on the isotope ratios were in the order of few ‰ and comparable with those obtained with the conventional analytical protocol. This new protocol will help to reduce the quantities analyzed from µg to ng, the liquid waste volume scale from mL to µL and the sample volumes form µL to nL
2
Oliveira, Felipe Valença de. "Chronus : um novo suplemento para a redução de dados U-Pb obtidos por LA-MC-ICPMS." reponame:Repositório Institucional da UnB, 2015. http://dx.doi.org/10.26512/2015.06.D.19559.
Повний текст джерелаАнотація:
Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, Pós-Graduação em Geologia, 2015.Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-02-25T11:38:58Z No. of bitstreams: 1 2015_FelipeValençadeOliveira.pdf: 5245176 bytes, checksum: 5a982ddd156db28d4bed918c900158db (MD5)
Approved for entry into archive by Guimaraes Jacqueline(jacqueline.guimaraes@bce.unb.br) on 2016-02-25T11:51:36Z (GMT) No. of bitstreams: 1 2015_FelipeValençadeOliveira.pdf: 5245176 bytes, checksum: 5a982ddd156db28d4bed918c900158db (MD5)
Made available in DSpace on 2016-02-25T11:51:36Z (GMT). No. of bitstreams: 1 2015_FelipeValençadeOliveira.pdf: 5245176 bytes, checksum: 5a982ddd156db28d4bed918c900158db (MD5)
A análise de isótopos de U-Pb por Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) se popularizou nas geociências em função do seu custo relativamente baixo, da razoável precisão obtida e da velocidade com que os dados podem ser gerados. Para estudos que requerem grande quantidade de idades, como na análise de proveniência de bacias sedimentares, esse método mostra-se muito vantajoso. Entretanto, essa mesma velocidade de análise é acompanhada por um grande volume de dados a serem reduzidos. O projeto aqui descrito teve como objetivo o emprego de métodos computacionais na automação do processo de redução de dados. Utilizando a linguagem Visual Basic for Applications (VBA), intrinsecamente relacionada ao Microsoft Excel, todo as etapas de redução foram incluídas em único programa: Chronus. Por meio desse programa é possível escolher os parâmetros pertinentes à redução (tipo de detectores, padrões analisados, método de propagação de incertezas, etc.), importar os dados brutos automaticamente, corrigir o branco do método, corrigir as razões das amostras usando os padrões e finalmente calcular as incertezas. O Chronus cria um arquivo no formato excel com diferentes planilhas, nas quais são guardadas as confingurações escolhidas, as informações de cada etapa da redução e os resultados. A capacidade do Chronus para redução de dados U-Pb por LA-ICPMS foi testada usando análises dos padrões de zircão 91500 (1065 Ma, Wiedenbeck et al., 1995) e Plešovice (337 Ma, Sláma et al., 2008), tomando o zircão GJ-1 (608 Ma, Jackson et al., 2004) como padrão primário. A propagação das incertezas do GJ-1 nas análises foi feita de duas maneiras: considerando as incertezas das análises antes e depois das amostras ou usando o Mean Square of the Weighted Deviates (MSWD) das razões de interesse do padrão. A redução de um grande número de amostras permitiu a observação de intensidades não esperadas da massa 202. Esse fenômeno foi observado também especificamente nas análises dos padrões citados anteriormente. Há uma aparente relação entre o conteúdo de Elementos Terras Raras (ETR) dos zircões com as intensidades da massa 202, talvez devido à formação de óxidos de ETR durante o carreamento do material proveniente da câmara de ablação para os detectores.
The U-Pb analysis by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) became popular in geosciences due to its low cost, reasonable precision and rapid analysis. For studies that require a large number of ages, like in sediment provenance studies, this method is advantageous. Although, the high analysis speed is also followed by a big volume of data to be reduced. The project described in this dissertation had the objective to use computational methods to automatize the data reduction process. Using the Visual Basic for Applications programming language, which is intrinsically related to Microsoft Excel, all data reducing steps were included in a single program: Chronus. By using this program it is possible to choose the analyses’ settings (the type of collectors, the analyzed standards, the error propagation method, etc.), automatically import the raw data, subtract the signal of the blank from the samples, correct the samples’ ratios based on the standards’ analyses and calculate the uncertainties. Chronus creates a Excel spreadsheet with many sheets where the settings, the information of each step of data reduction and the results are stored. The capacity of Chronus to reduce U-Pb data obtained by LA-ICPMS was tested using analyses of the 91500 (1065 Ma, Wiedenbeck et al., 1995) and Plešovice (337 Ma, Sláma et al., 2008) zircon standards, using the GJ-1 standard (608 Ma, Jackson et al., 2004) as primary standard. Propagation of the GJ-1’s uncertainties into analyses was done by two different ways: taking into account the uncertainties of GJ-1’s analyses before and after the sample or using the Mean Square of the Weighted Deviates (MSWD) of the standard’s ratios. Reducing a large number of samples allowed the observation of unexpected 202 mass signal. This phenomenon was observed also in the zircon standards discussed previously. It seems to have a relationship between the zircon grains’ Rare Earth Elements (REE) contents and the 200 mass intensity. It might be due to the REE oxide formation during the material transport from the ablation chamber to the detectors.
3
Mora, Claudio Alejandro Salazar. "Idades e cinemática do processo de anatexia de Crosta Continental profunda no domínio Norte da Nappe Socorro-Guaxupé, orógeno Brasilia Meridional." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/44/44143/tde-21012014-090557/.
Повний текст джерелаАнотація:
Na porção W-SW do lobo Guaxupé, pertencente à Nappe Socorro-Guaxupé, nos arredores da cidade de São José do Rio Pardo, é registrado um evento metamórfico e anatético de fácies granulito, sob condições de desidratação da hornblenda, com T >=850ºC. As rochas diatexíticas, que compõem as suítes São José do Rio Pardo (SJRP) e Pinhal, resultam desse evento de alta temperatura, ocorrido há ~625 Ma. As assinaturas geoquímicas e isotópicas sugerem uma geração a partir da anatexia da crosta continental inferior. Além disso, o enriquecimento em potássio da suíte SJRP indica uma afinidade vaugnerítica, a qual é caracterizada por altos conteúdos de Mg, elementos do tipo LILE (large ion lithophile elements), HFSE (high field strenght elements) e ETR-leves, além de valores negativos de \'épsilon\'Nd e razões de Sr iniciais baixas, ~0.706. O magmatismo vaugnerítico implica em um manto litosférico metassomatizado como fonte, o qual foi enriquecido por eventos de subducção precedentes. A presença de pseudomorfos de fusão nesses diatexitos indicam uma evolução quase isotérmica sob presença de líquido anatético. O transporte sin-magmático ocorreu para NE-E. A fonte de calor para esse metamorfismo pode estar associada à delaminação da base do arco magmático. O processo de fusão parcial gerou leucossomas charno-enderbíticos na Unidade Metatexítica, com assinaturas geoquímicas e isotópicas que indicam uma fonte crustal. Dessas rochas, foram separados cristais de zircão que mostraram duas populações distintas. A primeira, tipicamente com cristais prismáticos e bipiramidados, indicam idades em torno de 620 Ma, enquanto que a segunda, com cristais isométricos típicos de alto grau metamórfico, indicam idades em torno de 610 Ma. Em relação ao pico metamórfico de ~625 Ma, as idades mais jovens obtidas sugerem um período de 15 my em que predominaram altas temperaturas. O transporte tectônico para NW, em estado sólido de alta temperatura, é posterior à cinemática sin-magmática para NE, e deve estar associado à compressão da placa superior convergente, dentro desse período de alta temperatura. Esse regime tectônico é compatível com modelos recentes da tectônica Andina onde é descrita uma subducção horizontal (Pampean flat subduction). Dentre as rochas da Unidade Granulítica Basal, também submetida à fusão parcial por desidratação da hornblenda, ocorrem gnaisses com afinidade adakítica, sugerida pelas altas razões Sr/Y = 72.73, La/Yb = 23.07, \'(La/Yb) IND.N\' = 15.56, e teores de #mg = 51.77, Sr = 1062 ppm, Cr = 197 ppm e Ni = 103 ppm. Tal afinidade sugere magmas resultantes da fusão de um slab em subducção. A Nappe Socorro-Guaxupé admite uma evolução que se inicia, cerca de 670-640 Ma, com uma subducção inclinada para a geração de rochas cálcio-alcalinas com alguns membros adakíticos. É seguido um momento de colisão, entre 625 e 610 Ma, com a geração de rochas diatexíticas e metatexíticas de alto potássio, onde o arco migrou primeiramente para o ante-arco (estado subsólido) e depois em direção ao interior da placa superior (estado sólido). A estabilização da nappe se deu quando da colocação dos maciços sieníticos pós-tectônicos, Capituva e Pedra Branca.The W-SW portion of the Guaxupé Domain, nearby the São José do Rio Pardo city, records a granulite facies anatetic event under hornblende dehydration-melting conditions, i.e. T >=850ºC. The diatexitic rocks that are comprised within the São José do Rio Pardo and Pinhal suites resulted from this high-T metamorphic event, ca. 625 Ma. Geochemical and isotopic signatures suggest derivation from the lower continental crust. The K-rich SJRP suite also show geochemical affinity with vaugneritic rocks, suggested by high contents of Mg, LILE, HFSE and light-REE in addition to negative ?Nd and low Sr initial ratio (~0.706). Vaugneritic magmatism implies on a derivation from a metasomatized lithospheric mantle source enriched before partial melting in a previous subduction setting. Once both suites contain melt pseudomorphs, it is then suggested and isothermic evolution under the presence of melt. A syn-magmatic driven transport occurred towards NE-E, and the heat source for high-T conditions could be assigned to mantle delamination under the margmatic arc. Within the Metatexitic Unit, partial melting resulted in charno-enderbitic leucosomes whose geochemical and isotopic signatures indicate crustal sources. From these leucosomes, two different populations of zircon crystals were separated. The first, comprising bypiramidal-prismatic grains, yield ages around 620 Ma, whereas the second typology of zircons is isometric and soccer-ball type, yielding younger ages around 610 Ma. The latter typology is typical of high-T and melt-bearing rocks. Considering the 625 Ma metamorphic peak, the younger ages suggest a 15 my period when high-T conditions prevailed. Top-to-NW transport, under solid-state high-T conditions, can be associated to the compression of the upper convergent plate within this high-T period. Textural features suggest this transport to have occurred after the crystallization of the syn-magmatic rocks. The compression of the upper plate resembles recent models of the Andean orogenic cycle, where the Pampean flat subduction is described. Among the rocks of the Basal Granulitc Unit, which also underwent hornblende-dehydration partial melting, a gneissic rock shows adakitic affinity, suggested by Sr/Y = 72.73, La/Yb = 23.07, \'(La/Yb) IND.N\' = 15.56, #mg = 51.77, Sr = 1062 ppm, Cr = 197 ppm and Ni = 103 ppm. Adakitic magmas are thought to be slab melts. The Socorro-Guaxupé Nappe was built up between 670 and 640 Ma with a steep subduction and generation of calc-alkaline and subordinate adakitic rocks. A collisional setting, generating high-K diatexites and metatexites, took place between 625 and 610 Ma, where the arc firstly migrated (in subsolidus state) towards the forearc and then migrated (in solid state) towards the interior of the upper plate. Post-tectonic Capituva and Pedra Branca syenitic plutons intruded around 610 Ma, recording the arc migration ceasing.
4
Smith, Christopher James Martin. "Advances in U-Pb speleothem chronology using laser ablation MC-ICPMS techniques : applications in quantifying long-term rates of landscape change." Thesis, University of Bristol, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701652.
Повний текст джерелаАнотація:
The development of U-Pb dating techniques for speleothem deposits has enabled the scientific community to exceed the upper limit of the U-Th chronometer (-600 ka), creating new opportunities for innovative research into palaeoenvironmental change over 106-107 year timescales. However, despite the great potential of the technique, its application in research has been limited, with just 21 papers published over the last 17 years. This paucity of research can be attributed to the technical challenges associated with measuring small quantities of radiogenic Pb and limited UlPb ratio spread measurable by low-spatial resolution techniques such as 10-TIMS and MC-ICPMS. In this thesis I investigate the use of in-situ U/Pb ratio analysis by LA MC-ICPMS, to take advantage of the increased spatial resolution compared to conventional low-spatial resolution techniques in order to better resolve UlPb ratio heterogeneity in speleothem calcite. To test the feasibility, accuracy and precision of U-Pb speleothem dating by LA MC-ICPMS, four speleothem samples, previously dated by low-spatial resolution U-Pb methods, were reanalysed using a 193 nm ArF excimer laser ablation system, coupled to a Nu Plasma HR MCICPMS. Following the initial feasibility study, rates of Quatemary landscape evolution were investigated at two field sites: the Ogof Draenen cave system, Brecon Beacons National Park, South Wales, UK; and the Mulu caves of the Gunung Mulu National Park, Malaysian Borneo. In the feasibility study (Chapter 3), U-Pb dating by LA MC-ICPMS of samples of known age, ranging from -0.25-2.50 Ma, were shown to be concordant with conventional low-spatial resolution U-Pb dating results, yielding typical age uncertainties of 5-6% per isochron. Using age-depth modelling techniques, age uncertainties of as little as 2-3% were achieved. Under normal conditions, U/Pb ratio data for a 40-point isochron could obtained in -1 hour by LA MC-ICPMS, with sample consumption rates of as little as -0.026 mg of calcite per isochron. U-Pb dating of speleothem samples from Ogof Draenen (Chapter 4) was used to quantify past rates of fluvial incision in the Usk Valley during the Quaternary, yielding maximum incision rates of between 0.194-0.231 m ka-1 over the last -1250 ka. Scarp retreat rates along western flank of the Usk Valley for the same period were highly variable and localised, with rates of as little as 0.06 m ka-1 at Cwm y Nant up to 0.542 m ka-1 at Cwm Llanwenarth. U-Pb dating of speleothems from the Mulu caves (Chapter 5) presented a greater challenge, with many samples displaying anomalous UlPb ratios, indicating the presence of unsupported common Pb. Despite this, U-Pb dating of flowstone WR-09-18-03 by LA MC-ICPMS yielded a basal age of 1181.3 +278.0/-256.1 ka, equating to a mean incision rate of 0.216 +0.060/-0.41 m ka-1. This result shows a good level of agreement with the mean rate of 0.190 +0.030/-0.040g m ka-1 obtained by Farrant et al. (1995) for palaeomagnetic sediment dating. In summary, U-Pb dating of speleothems by LA MC-ICPMS offers several key advantages over conventional low-spatial techniques, including a significant increase in measurable U/Pb ratio spread for individual isochrons and a major reduction in sample preparation and analysis time, as well as sample consumption rates. Ultimately, this technique represents a new and valuable alternative to conventional low-spatial resolution U-Pb dating methods.
5
Yamagata, Yuko. "Iron isotopic signatures for marine animals of various habitat." Kyoto University, 2019. http://hdl.handle.net/2433/242621.
Повний текст джерела
6
Melleton, Jérémie. "Modalités du recyclage de la croûte continentale dans l'orogène varisque par traçage in situ des zircons hérités (mesures U -Pb/LA-MC-ICPMS)." Phd thesis, Université d'Orléans, 2008. http://tel.archives-ouvertes.fr/tel-00388706.
Повний текст джерелаАнотація:
Ce travail de thèse est essentiellement consacré à l'investigation des populations de zircons et de l'âge des protolithes des formations varisques grâce à une datation U-Pb in situ systématique par le couplage Laser/MC-ICPMS, dans des formations orthodérivées, métasédimentaires et magmatiques tardi-orogéniques du Massif Central français et du domaine Sud armoricain. Cette étude a montré que les populations de zircons sont largement héritées, s'étalant de l'Archéen au Paléozoïque inférieur. L'ensemble des pics d'âges obtenus, ainsi que l'absence d'âge mésoprotérozoïque (1.7-1.1 Ga) accréditent l'affinité gondwanienne de ces formations. Des âges maximum de dépôt sont proposés pour les métasédiments des principales unités définies dans le Massif Central. Ces âges maximum de dépôt sont décroissants suivant l'empilement lithotectonique reconnu. En marge de ce travail, nous avons pu déterminer que les âges de mise en place des granitoïdes du Sillon Houiller (Massif Central) et du golfe du Morbihan se situent aux alentours de 300 Ma. Des âges plus anciens, principalement obtenus sur monazite lors d'études antérieures, ont été réinterprétés comme des âges hérités. L'abondance de zircons hérités d'âge ordovicien et néoprotérozoïque met en évidence la large contribution des métagranites et métasédiments fertiles de ces périodes dans la source des granites tardi-orogéniques varisques. Le granite de Sarzeau expose de plus les traces d'un protolithe silurien. Le recyclage de la croûte continentale est caractérisé par une évolution polycyclique au cours de l'orogénèse varisque, avec tout d'abord l'érosion de formations du craton africain, majoritairement d'âge néoprotérozoïque, puis la superposition des événements magmatiques cambro-ordoviciens et syn-orogéniques varisques.
7
Breton, Thomas. "Isotopes du tungstène : nouvelles applications à l'étude des processus terrestres et astéroïdaux." Toulouse 3, 2014. http://thesesups.ups-tlse.fr/3076/.
Повний текст джерелаАнотація:
Le chronomètre 182Hf-182W (hafnium-tungstène) et les isotopes du tungstène (W) sont aujourd'hui couramment utilisés en cosmochimie, et de plus en plus en géochimie. Ils servent notamment à dater les premières étapes de formation de notre système solaire (radiochronomètre), mais aussi à étudier l'effet des rayonnements cosmiques sur la matière (effets cosmogéniques) ou encore à retracer l'environnement stellaire de notre soleil au moment de sa formation (anomalies nucléosynthétiques). Sur Terre, ils sont utilisés depuis peu pour tester l'hypothèse du " Late Veneer " (vernis tardif) et pour rechercher des signatures géochimiques datant d'avant ce vernis tardif. Toutes ces signatures isotopiques sont dites " indépendantes de la masse " parce qu'elles affectent plus ou moins les différents isotopes, sans lien avec leurs écarts de masses. Ce travail propose une nouvelle application de l'analyse des isotopes du W. Une méthode analytique innovante est présentée pour le fractionnement " dépendant de la masse ", c'est-à-dire le fractionnement des isotopes stables induit par les processus géologiques sur les astéroïdes, les planétésimaux, les planètes et leurs satellites naturels ou encore dans les environnements terrestres : fusion, cristallisation, métamorphisme, altération, hydrothermalisme, contamination, mélanges et bien d'autres. Le fractionnement des isotopes stables du W a été mesuré pour une série d'échantillons terrestres et surtout extraterrestres (chondrites ordinaires, chondrites carbonées, eucrites, météorites de fer). La gamme de variations observées va de -0,03 à +0,57 ‰ par unité de masse atomique. Nous avons mis en évidence que l'altération perturbait le chronomètre 182Hf-182W, les âges des échantillons altérés pouvant n'être que des âges apparents. De façon à mieux comprendre l'effet de l'altération sur le système Hf-W, nous avons mis en place des expériences de lixiviation de roches terrestres (lherzolite et dunite) sous atmosphère contrôlée, en système fermé et en système semi-ouvert. Nous avons complété ces expérimentations par des modélisations numériques à l'aide du logiciel PHREEQC. Les expériences montrent une grande différence de comportement de l'Hf par rapport au W en solution, confortant ce qui avait été observé dans les météorites : le W est beaucoup plus mobile que le Hf, ce qui fractionne le rapport Hf/W de l'échantillon. Ainsi, l'altération perturbe le système Hf-W et le radio-chronomètre associé. Enfin, ayant constaté ces effets de l'altération, nous avons choisi d'étudier une chondrite CR non altérée. En effet ces échantillons sont considérés comme parmi les plus primitifs du système solaire, et présentent des indices d'un début de différenciation. Nous avons donc étudié en détail la météorite de Tafassasset, une CR anormale, non altérée mais très métamorphisée, sur laquelle nous avons réalisé un ensemble d'analyses (182Hf-182W, minéralogie, micro-tomographie X, modélisation de l'évolution du corps parent). Cette météorite s'est révélée être en fait une achondrite primitive partiellement différenciée, et formée très précocement dans l'histoire du système solaire : elle s'est accrétée ~1 Ma après la formation des CAIThe 182Hf-182W chronometer and, more generally, tungsten (W) isotopes are commonly used to address several scientific problems in cosmochemistry and, more recently, in geochemistry. They are, for instance, very useful tools for dating the first stages of our solar system history (radiochronometer), but also for studying the effects of galactic cosmic rays interacting with planetary or asteroidal surfaces (cosmogenic effects), or for glancing at the stellar environment of our nascent solar system (nucleosynthetic anomalies). On Earth, they have recently been used to test the Late Veneer hypothesis and to look for geochemical signatures dating back from before this late event. All these scientific problems use isotope signatures that are called "mass-independent" because they affect more some isotopes than others, independently of their masses. In this work, I propose new applications for the W isotopes system. I present an innovative method for measuring the "mass-dependent" fractionation of W stable isotopes, i. E. The fractionation induced by geological processes on asteroids, planetesimals, planets and their natural satellites, or in terrestrial environments: melting, crystallization, metamorphism, alteration, hydrothermal fluid circulations, contamination, mixing and much more. This new approach has been applied to a series of terrestrial and extraterrestrial samples (ordinary and carbonaceous chondrites, eucrites, iron meteorites). The measured isotope compositions range from -0,03 to +0,57 ‰ par atomic mass unit. It seems that alteration processes disturb the 182Hf-182W clock. As a consequence, 182Hf-182W ages measured on extensively altered samples could be apparent ages and have no chronological meaning. In order to better understand the effects of aqueous alteration on the H-W system, we set up a series of experiments in which we simulated the lixiviation of terrestrial samples (lherzolite and dunite) under controlled atmosphere, in both closed and semi-opened systems. These experiments were compared with PHREEQC geochemical modeling results. Experiments show a significant difference between the behaviors of Hf and W in solution, W being much more mobile than Hf. This is in line with our observations on altered carbonaceous chondrites: alteration may fractionate the Hf/W ratio, thus disturbing the Hf-W system and its associated radiochronometer. Having shown the effects of aqueous alteration on the Hf-W system, we chose to study an unaltered CR chondrite: these samples are of high interest for our knowledge of the early solar system, as they are considered as very pristine while presenting some clues of the earliest steps of differentiation. We studied the Tafassasset meteorite, generally considered as an anomalous and unaltered CR chondrite. We combined various analyses on this sample: 182Hf-182W chronology, micro-tomography, mineralogy and modeling of the thermal evolution of its parent body. This meteorite happened to be a partially differentiated primitive achondrite that accreted early in our solar system history, ca. One million years after CAIs
8
Sabriana, Ortega Georgia Irai. "Développement de méthodes analytiques pour la détermination de l’isotopie du plomb et des éléments traces dans des produits pétroliers (huile, asphaltène, kérogène, roche mère). Application à la datation de la génération du pétrole et de la déposition de la roche mère dans un bassin pétrolier." Thesis, Pau, 2012. http://www.theses.fr/2012PAUU3043/document.
Повний текст джерелаАнотація:
La datation de l’âge de génération des hydrocarbures et de la déposition de la roche mère fournit des informations importantes dans la prospection pétrolière. Dans ce travail, différentes stratégies ont été étudiées pour la détermination des métaux traces, et des rapports isotopiques du plomb dans des produits pétroliers par des techniques de spectrométrie de masse. Les stratégies d’analyses développées dans ce travail ont été utilisées pour estimer l’âge de génération du pétrole, ainsi que l’âge de déposition de la roche mère âge du « New Albany shales » dans le basin d’Illinois, en utilisant les géochronomètres U-Th-Pb. Les ages déterminés par la méthode U-Th-Pb sont en très bon accord avec ceux prédits par les modèles numériques géologiques, ce qui démontre le potentiel de cette approche pour étudier l’histoire de la formation des hydrocarbures et dans la recherche de nouvelles sources d'hydrocarburesTiming crude oil generation and source rock deposition provides important clues in petroleum prospection. In this work, different analytical procedures were developed for trace metals and Pb isotope ratio were determination crude oils and related products. These analytical strategies were then used, for the first time, to assess the applicability of the U-Th-Pb geochronometers for timing source rock deposition age and crude oil generation in the Illinois Basin. Ages determined are in good agreement with those predicted by geological numerical models, demonstrating the potential of these geochronometers to study the history of hydrocarbons formation and to find new hydrocarbon sources
9
Gonzalez, Cécile. "Quantification de l'acidification de l'océan par l'analyse géochimique des coraux profonds." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112009/document.
Повний текст джерелаАнотація:
L’acidification des océans provoquée par l’absorption du CO2 atmosphérique par l’eau de merest devenue une préoccupation écologique majeure et menace déjà les organismes calcifiants. Suiteà la révolution industrielle, le pH de l’océan de surface a diminué de 0,1 unité-pH. En revanche, celuides eaux profondes reste peu documenté. Les isotopes du bore (11B) dans les carbonatesbiogéniques se sont révélés être un puissant outil géochimique pour la reconstitution du pH, mais n’apas encore été appliqué aux coraux profonds. Un travail analytique sur MC-ICPMS Neptune et uneanalyse géochimique de ces coraux ont été effectués afin de reconstituer et quantifier l’acidificationdes océans. De même, la valeur 11B de l’eau de mer utilisée pour calculer les paléo-pH a étérevisitée et l’homogénéité des océans vérifiée.L’analyse de deux colonies modernes de Lophelia pertusa et Madrepora oculata a permis dequantifier un taux d’acidification pendant la fin du XXème siècle pour les eaux de sub-surface en mer deNorvège et cela après établissement d’une calibration expérimentale à partir de coraux de culture.L’analyse géochimique des coraux profonds a mis en évidence un effet vital lié à la physiologie quidoit être considéré pour quantifier avec précision la variabilité du pH. Celui-ci peut être en partiecorrigé par une analyse statistique des isotopes stables B, C et O. Cette étude a aussi révélél’influence de l’hydrodynamique régionale. Enfin les variations naturelles du pH pendant l’Holocène etle Dernier Maximum Glaciaire sur des coraux profonds fossiles méditerranéens ont été établies etcelles pendant l’aube de l’explosion de la diversité biologiqueOcean acidification is caused by the absorption of rising atmospheric CO2 by seawater andrepresents a major environmental issue. Since the beginning of the industrial era, seawater pH hasdecreased by 0.1 pH units and is already threatening calcifying organisms. Boron isotopes (11B) haveproved to be a powerful geochemical tool for the reconstruction of pH variations, but has not yet beenapplied to deep-sea corals (DSC). Accurate and precise measurements of boron isotopes in coralsand seawaters were performed in order to measure small pH variations.The technique of pH reconstruction based on boron isotopes (pH-11B) was used on two specimens of the DSC Madrepora oculata and Lophelia pertusa collected alive in the Norwegian Sea and spanning an age of 40 (3) and 67 (3) years, respectively. Acidification rates were calculated by applying a new pH-11B calibration obtained from the geochemical analysis M. oculata and L. pertusa samples cultured under different pCO2 conditions. The contribution of a biological-related vital effect on d11B was observed at macrometer scale, and a correction was finally suggested based on oxygen and carbon isotopes. Overall, the coral δ 11B-based reconstructions show a pH decrease in the Norwegian Sea since the 1940s, which seems to be related to the local hydrodynamics. The pH-11B technique was also applied to fossil DSC fragments from two “on-mound sediment cores” retrieved in the Siculo-Tunisian Strait with the aim to reconstruct the pH during the Last Glacial Maximum and the Holocene periods. Finally, well-preserved limestone samples from the stratigraphic sequence Nama (551-543 Ma) in Namibia were investigated for 11B to study the pH variations at the beginning of the Cambrian evolutive radiation
10
Boccas, Matthieu. "Développement d’une méthode de micro-échantillonnage de terrain reposant sur un tandem LIBS-portable / Module de récupération des particules induites pour analyses élémentaires et isotopiques : Applications archéologiques." Electronic Thesis or Diss., Pau, 2024. http://www.theses.fr/2024PAUU3038.
Повний текст джерелаАнотація:
Les études archéologiques présentent la particularité d’être fréquemment soumises à des impératifs de préservation stricts des échantillons, ces derniers pouvant être précieux, fragiles et/ou limités en termes de quantité. Dans certains contextes l’échantillonnage peut également nécessiter d’être réalisé in-situ et viser des surfaces ou cibles difficiles d’accès. Malheureusement, peu de méthodes ne permettent de nos jours de pouvoir répondre à toutes ces problématiques à la fois, et un véritable besoin pour des méthodes d’échantillonnage ciblées et peu invasives émerge. Cela est particulièrement vrai notamment lorsque les analyses envisagées reposent sur le prélèvement obligatoire de matière et ne peuvent être substituées par des méthodes non destructives. Pour répondre à cette situation, ce projet de thèse s’est articulé autour de la conception d’une méthode de micro-échantillonnage de terrain par ablation laser portable, permettant un échantillonnage respectueux dans un format adapté au terrain et aux environnements complexes. Après avoir développé la méthode, nous avons exploré son potentiel dans le cas de la datation uranium-thorium d’échantillons de spéléothèmes en calcite, fréquemment associés aux œuvres pariétales préhistoriques. La méthode d’échantillonnage proposée repose sur l’utilisation des capacités naturelles d’ablation laser d’un LIBS-portable (Z300, Sciaps), dont nous avons modifié l’extrémité par impression 3D afin de pouvoir lui greffer un module de collecte des particules. Par cette combinaison, ce système permet d’obtenir à la fois des informations sur site directement à partir des spectres LIBS mais également de collecter les particules induites par laser afin de pouvoir les analyser par différentes techniques de spectrométrie de masse. Nous avons ensuite adapté cette méthode au prélèvement de microéchantillons (~1mg) de calcite (principalement des spéléothèmes mais également des coraux) avec pour objectif leur datation par la méthode U/Th. Dans le cadre de cette application, nous avons également dû définir une méthode de solubilisation de particules collectées par ablation laser afin d’extraire les informations isotopiques qu’elles contiennent. Une première phase de tests préliminaires fut réalisée et deux échantillons (un spéléothème et un corail) furent datés par MC-ICP-MS (nu 1700) avec succès en suivant le protocole de datation conventionnel pour ce type d’analyse. Nous avons par la suite travaillé sur une méthode de préparation chimique alternative en utilisant la méthode de l’extraction au point trouble (ou « CPE ») qui permet entre autres de s’affranchir des contraintes de la méthode conventionnelle, et notamment l’emploi de traceurs radioactifs. Pour cela, nous avons développé et optimisé un système CPE permettant l’extraction quantitative des isotopes de l’uranium et du thorium, dimensionné pour des microéchantillons de calcites d’1 mg concentrés jusqu’à 2 ppm en uranium et thorium total. Cette méthode fut éprouvée au travers de la datation d’échantillons connus, prélevés selon la méthode développée pour ce travail de thèse et analysés par QQQ-ICP-MS (Agilent 8900). Nous sommes parvenus à établir une preuve de concept pour l’ensemble du protocole analytique développé. Enfin, nous avons également exploré une application différente pour cette méthode de prélèvement, en travaillant sur les pigments de cinabre (Hg-S) utilisés dans des fresques murales romaines découvertes à Pompéi. L’ablation laser de ces pigments à cependant conduit à un phénomène de fractionnement isotopique sur le mercure, modifiant leur signature isotopique et mettant ainsi en lumière certaines limites de la méthodeArchaeological studies are often subject to strict preservation requirements, as samples may be valuable, fragile and/or limited in quantity. In some contexts, sampling may also need to be carried out in situ and may involve surfaces or targets that are difficult to access. Unfortunately, few methods are currently able to address all of these issues at once, and there is a real need for targeted, minimally invasive sampling methods. This is particularly the case when the analyses necessarily require the removal of material and cannot be replaced by non-destructive methods. In response to this situation, this PhD project focused on the development of a portable laser ablation field micro-sampling method designed to provide respectful sampling in a format suitable for field use and complex environments. After the development of the method, we explored its potential in the case of uranium-thorium geochronometer dating of geological samples, in particular calcite speleothems often associated with prehistoric cave art. The proposed sampling method exploits the natural laser ablation capabilities of a portable LIBS (Z300, Sciaps), the tip of which has been modified by 3D printing to incorporate a particle collection module.This combination allows to obtain on-site information directly from LIBS spectra and to collect laser-induced particles for ICP-MS analysis. We then adapted this method to the collection of micro-samples (~1mg) of calcite (mainly speleothems, but also corals) with the aim of dating them by the U/Th method. As part of this application, we also had to define a method for solubilising the particles collected by laser ablation in order to extract the isotopic information they contain. A first step of preliminary testing was then carried out and two samples (a speleothem and a coral) were successfully dated by MC-ICP-MS (nu 1700) following the conventional dating protocol for this type of analysis. We then worked on an alternative chemical preparation method using Cloud Point Extraction (CPE), which in this case allows uranium and thorium to be extracted without the constraints of the conventional preparation method, in particular the use of radioactive tracers.To this end, we have developed and optimized a CPE system for quantitative extraction of uranium and thorium isotopes, designed for 1 mg calcite micro-samples containing a maximum concentration of 2 ppm of total uranium and thorium. This method was tested by dating a set of known samples collected using the method developed for this thesis and analyzed by Q3-ICP-MS (Agilent 8900). This final study provided a proof of concept for the entire analytical protocol developed. Finally, we also explored another application for this sampling method, working on cinnabar pigments (Hg-S) used in Roman wall frescoes discovered in Pompeii. However, laser ablation of these pigments led to isotopic fractionation of the mercury, altering its isotopic signature and highlighting certain limitations of the method
Частини книг з теми "Mc-Icpms / icpms"
1
Fisher, Christopher M., and Jeffery D. Vervoort. "Laser ablation-MC-ICPMS." In Reference Module in Earth Systems and Environmental Sciences. Elsevier, 2024. http://dx.doi.org/10.1016/b978-0-323-99762-1.00114-5.
Повний текст джерелаТези доповідей конференцій з теми "Mc-Icpms / icpms"
1
McInnes, Brent, Kai Rankenburg, Brad McDonald, Noreen Evans, and Bruno Vieira Ribeiro. "Comparing CRC-MC-ICPMS to QQQ-ICPMS/MS for in situ Rb-Sr applications." In Goldschmidt 2024. United States of America: Geochemical Society, 2024. https://doi.org/10.46427/gold2024.21472.
Повний текст джерела
2
Scott, Sean, Madeleine Mathews, Amy Plechacek, Gary Krinke, Michael Populin, and Matthew Ginder-Vogel. "Combined 226Ra + 228Ra analysis in groundwater by MC-ICPMS." In Goldschmidt2022. France: European Association of Geochemistry, 2022. http://dx.doi.org/10.46427/gold2022.10255.
Повний текст джерела
3
Hirata, Takafumi, Andy Burrows, and Phil Freedman. "Analytical Capability of a High-Time Resolution-Multiple Collector-ICPMS (HTR-MC-ICPMS) system for Geochemical and Cosmochemical Studies." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.6033.
Повний текст джерела
4
Levier, Martin, Matthieu Roy-Barman, Christophe Colin, and Arnaud Dapoigny. "Seawater 227Ac Analysis by ID-Mc-ICPMS: A GEOTRACES Challenge." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.1466.
Повний текст джерела
5
Bevan, Dan, Christopher D. Coath, Jamie Lewis, Johannes B. Schwieters, Nicholas Lloyd, Grant Craig, and Tim Elliott. "Detrital K-Feldspar Geochronology by Collision Cell MC-ICPMS/MS." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.181.
Повний текст джерела
6
Griffin, Julie M., Jitao Chen, Isabel P. Montañez, Justin Glessner, and Dillon J. Osleger. "SOLUTION-LASER ABLATION MC-ICPMS COMPARISONS OF CONODONT APATITE FOR 87SR/86SR." In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-284126.
Повний текст джерела
7
Ma, Jin-Long, Guan-Hong Zhu, Gang-Jian Wei, and Le Zhang. "The Measurement of Boron Isotope for Geological Standard Materials by Using MC-ICPMS." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.1679.
Повний текст джерела
8
Xu, Juan, and Shouye Yang. "Critical Considerations for Precise Determination of Stable Strontium Isotopic Compositions by MC-ICPMS." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.2944.
Повний текст джерела
9
Xu, Lei, Jin-Hui Yang, Zhao-Chu Hu, and Lei Xu. "Microbeam isotopic analysis of geological samples by LA-MC-ICPMS. IAG Young Scientists Award." In Goldschmidt2022. France: European Association of Geochemistry, 2022. http://dx.doi.org/10.46427/gold2022.9734.
Повний текст джерела
10
Schannor, Mathias, Heike Traub, Marcus Oelze, Jochen Vogl, and Björn Meermann. "Developing matrix-matched standards for LA-MC-ICPMS analysis of Cu isotopes in biological material." In Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.19355.
Повний текст джерелаЗвіти організацій з теми "Mc-Icpms / icpms"
1
Williams, R. Analysis of Uranium and Plutonium by MC-ICPMS. Office of Scientific and Technical Information (OSTI), February 2005. http://dx.doi.org/10.2172/917910.
Повний текст джерела
2
Williams, R., V. Genetti, and E. Ramon. Purification of U and Pu from Bulk Environmental Samples for Analysis by MC-ICPMS. Office of Scientific and Technical Information (OSTI), February 2005. http://dx.doi.org/10.2172/917901.
Повний текст джерела