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Identification of brominated organic compounds in aquatic biota and exploration of bromine isotope analysis for source apportionmentUnger, Maria January 2010 (has links)
Brominated organic compounds (BOCs) of both natural and anthropogenic origin are abundant in the environment. Most compounds are either clearly natural or clearly anthropogenic but some are of either mixed or uncertain origin. This thesis aims to identify some naturally produced BOCs and to develop a method for analysis of the bromine isotopic composition in BOCs found in the environment. Polybrominated dibenzo-p-dioxins (PBDDs) in the Baltic Sea are believed to be of natural origin although their source is unknown. Since marine sponges are major producers of brominated natural products in tropical waters, BOCs were quantified in a sponge (Ephydatia fluviatilis) from the Baltic Sea (Paper I). The results showed that the sponge does not seem to be a major producer of PBDDs in the Baltic Sea. In this study, mixed brominated/chlorinated dibenzo-p-dioxins were however discovered for the first time in a background environment without an apparent anthropogenic source. The use of nuclear magnetic resonance spectroscopy (NMR) is unusual in analytical environmental chemistry due to its sample requirements. Preparative capillary gas chromatography was used to isolate a sufficient amount of an unidentified BOC from northern bottlenose whale (Hyperoodon ampullatus) blubber (Paper II) to enable NMR analysis for identification of the compound. The bromine isotopic composition of BOCs may give information on the origin and environmental fate of these compounds. The first steps in this process are the development of a method to determine the bromine isotope ratio in environmentally relevant BOCs (Paper III) and measuring the bromine isotope ratio of several standard substances to establish an anthropogenic endpoint (Paper IV). / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.
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Approches archéométriques des productions faïencières françaises au XVIIIe siècle : le cas de la manufacture Babut à Bergerac (env. 1740 -1789)Emery, Laetitia 26 June 2012 (has links) (PDF)
La faïence est une céramique caractérisée par son revêtement vitreux blanc opaque, grâce à l'adjonction d'oxyde d'étain ; sur ce fond on peut apposer les décors polychromes. Résultant d'une technologie abbaside (VIIIe siècle), elle connait son apogée en France au XVIIIe siècle. Les précédentes études menées sur la faïence moderne ont mis en évidence la nécessité de procéder à une approche pluridisciplinaire pour appréhender ce matériau complexe, ses techniques de fabrication, et cerner les enjeux de sa production. Ce travail de recherche s'inscrit dans la continuité pour s'élargir aux productions faïencières du Sud Ouest de la France quelques peu délaissées du point de vue archéométrique. La manufacture Babut, première faïencerie établie à Bergerac, fut sélectionnée dans ce but. La production perdure sur cinquante ans environ, jusqu'à la Révolution Française.En prenant en considération ces observations, cette thèse a permis tout d'abord d'identifier la production du point de vue des matériaux et des techniques, de mettre en place un référentiel géochimique, ainsi qu'établir un corpus stylistique de base pour cette manufacture. Ensuite l'étude a porté sur l'évaluation du potentiel de méthodes d'analyses non destructives pour l'attribution de provenance directe à partir de la surface des glaçures. Et enfin ce travail a permis d'examiner la place de la faïence bergeracoise et de sa production au sein du tissu industriel régional, et les replacer dans le contexte plus général de la production faïencière française à l'aube de la Révolution industrielle.
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Chimie et dépôt de l'aérosol minéral en zone océanique australeHeimburger, Alexie 16 July 2013 (has links) (PDF)
Les apports atmosphériques sont suspectés de jouer un rôle important dans les processus biogéochimiques des régions océaniques HNLC. Des échantillons de dépôt atmosphérique total et d'aérosols ont été collectés en continu entre 2009 et 2010 dans l'océan austral indien, aux îles Kerguelen et de Crozet. Ils ont été mesurés par HR-ICP-MS. Les concentrations en surface des aérosols terrigènes sont basses et ne peuvent rendre compte des flux de dépôt de poussières qui sont plus élevés que ceux précédemment observés pour la région mais qui restent en adéquation avec les modèles atmosphériques. Le calcul des coefficients d'abattement suggère que l'aérosol mesuré en surface n'est pas représentatif de celui qui va générer le dépôt et qui est présent plus haut dans la colonne troposphérique, ce qui interdit ici l'estimation du flux à partir de ces mesures. Les flux de dépôt ont été établis pour une large gamme d'éléments identifiés comme venant de source terrigène ou marine. Pour certains d'entre eux (Pb, As, ...), une contribution anthropique a été observée pendant l'hiver austral. Les flux des éléments crustaux Al, Fe, Mn et Si sont similaires pour Kerguelen et Crozet ; ceux des autres éléments non marins sont différents d'un facteur deux à cinq avec un gradient décroissant de Crozet aux Kerguelen. Les rapports isotopiques de plomb montrent que le dépôt reçu aux Kerguelen provient principalement d'Amérique du sud ; le dépôt à Crozet semble fortement influencé par les apports africains. Les profils de REE pourraient confirmer ces observations. Les concentrations de métaux sont très basses dans les pluies avec une solubilité très élevée.
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Selenium cycling in volcanic environments: the role of soils as reactive interfacesFloor, Geerke Henriette 29 March 2011 (has links)
Selenium (Se) is an element with important health implications that is emitted in significant amounts from volcanoes. Attracted by the fertility of volcanic soils, around 10% of the world population lives within 100 km of an active volcano. Nevertheless, the behaviour of Se in volcanic environments is poorly understood. Therefore, the main aim of this thesis is to investigate the role of soils in the Se cycling in volcanic environments. Prior to the geochemical studies, precise and accurate methods for the determination of Se contents, speciation and isotopic signatures were developed. Afterwards, a combination of field studies and lab controlled experiments were performed with soils from two contrasting European volcanic settings: Mount Etna in Sicily (Italy) and Mount Teide in Tenerife (Spain). The results showed a strong link between Se behaviour and soil development, indicating that Se mobility in volcanic soils is controlled by sorption processes and soil mineralogy. / El selenio (Se) tiene afectas sobre la salud y es emitido por los volcanes. Atraída por la fertilidad de los suelos volcánicos, un 10% de la población mundial vive <100 km de volcanes activos. Sin embargo, el comportamiento geoquímico del Se en ambientes volcánicos es aún poco conocido. El objetivo de esta tesis es contribuir a la comprensión del papel del suelos en el ciclo del Se en medios volcánicos. En una primera etapa se desarrollaron métodos analíticos para determinar el contenido, la especiacíon y las relaciónes isotópicas del Se. Los estudios geoquímicos se realizaron con suelos de dos lugares con características muy distintas: el Monte Etna (Italia) y el volcán Teide (Tenerife). Los estudios de terreno y de laboratorio revelaron una gran interrelación entre el comportamiento del Se y el desarrollo de suelos, y que la movilidad de Se está controlado por los procesos de adsorción y la mineralogía en suelos volcánicos.
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Improving figures of merit and expanding applications for inductively coupled plasma mass spectrometryFinley-Jones, Haley Joy 03 December 2010 (has links)
Although inductively coupled plasma mass spectrometry (ICP-MS) is generally considered a reliable analytical technique, increasing demands on its capabilities require continued research and improvements. ICP-MS is susceptible to both matrix effects and drift, leading to a decline in accuracy and precision. A number of techniques are routinely used to compensate for these issues. Internal standardization is one such solution that requires relatively simple sample preparation and yet offers the possibility of improving both accuracy and precision. In order to be effective, an optimal analyte/internal standard pair must be chosen. Traditionally, analyte/internal standard pairs are chosen based on similarities in mass and/or ionization potential. The present studies sought to develop a program that determined standards based on the minimization of analytical error. 102 masses were monitored over 27 perturbations, i.e., changes to sample matrix and operating parameters. The standard deviations of the analyte/internal standard ratios were then used as a measure of internal standard performance. A thorough statistical analysis was conducted to determine trends between a good analyte/internal standard pair and similarities in chemical property. Similarities in mass offered the strongest relationship to a good internal standard choice, although many exceptions existed. The program was then tested over time and multiple instrument optimizations as well as on a completely different ICP-MS instrument. Results of these tests suggest that the data originally collected for the prediction program is not instrument-specific and thus provided a broader base of useful applications.
Due to its unmatched sensitivity and multielement capabilities, ICP-MS is frequently utilized for biological samples. A more recent application, however, seeks to use ICPMS for the purpose of determining specific associations between metals and proteins. Such speciation requires a high resolution and reproducible separation prior to ICPMS analysis. Gel electrophoresis offers good separation and is well matched with the scanning properties of laser ablation sample introduction. The present study utilized native gel electrophoresis coupled with a uniquely modified electroblot system to improve sensitivity and to elucidate additional information. Chemically modified quartz fiber filters were successfully used as the transfer membrane to improve protein and metal capture efficiency. / text
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Effet du calcium, plomb et cuivre sur la bioaccumulation du cadmium et la production des phytochélatines par Chlamydomonas reinhardtiiAbboud, Pauline 05 1900 (has links)
Dans les milieux contaminés par les métaux, les organismes vivants sont exposés à plusieurs d’entre eux en même temps. Les modèles courants de prédiction des effets biologiques des métaux sur les organismes (p. ex., modèle du ligand biotique, BLM ; modèle de l’ion libre, FIAM), sont des modèles d’équilibre chimique qui prévoient, en présence d'un deuxième métal, une diminution de la bioaccumulation du métal d’intérêt et par la suite une atténuation de ses effets. Les biomarqueurs de toxicité, tels que les phytochélatines (PCs), ont été utilisés comme étant un moyen alternatif pour l’évaluation des effets biologiques. Les phytochélatines sont des polypeptides riches en cystéine dont la structure générale est (γ-glu-cys)n-Gly où n varie de 2 à 11. Leur synthèse semble dépendante de la concentration des ions métalliques ainsi que de la durée de l’ exposition de l’organisme, aux métaux. L'objectif de cette étude était donc de déterminer, dans les mélanges binaires de métaux, la possibilité de prédiction de la synthèse des phytochélatines par les modèles d’équilibres chimiques, tel que le BLM. Pour cela, la quantité de phytochélatines produites en réponse d’une exposition aux mélanges binaires : Cd-Ca, Cd-Cu et Cd-Pb a été mesurée tout en surveillant l’effet direct de la compétition par le biais des concentrations de métaux internalisés. En effet, après six heures d’exposition, la bioaccumulation de Cd diminue en présence du Ca et de très fortes concentrations de Pb et de Cu (de l’ordre de 5×10-6 M). Par contre, avec des concentrations modérées de ces deux métaux, le Cd augmente en présence de Cu et ne semble pas affecté par la présence de Pb. Dans le cas de la compétition Cd-Cu, une bonne corrélation a été observée entre la production de PC2, PC3 et PC4 et la quantité des métaux bioaccumulés. Pour la synthèse des phytochélatines et la bioaccumulation, les effets étaient considérés comme synergiques. Dans le cas du Cd-Ca, les quantités de PC3 et PC4 ont diminué avec le métal internalisé (effet antagoniste), mais ce qui était remarquable était la grande quantité de cystéine (GSH) et PC2 qui ont été produites à de fortes concentrations du Ca. Le Pb seul n’a pas induit les PCs. Par conséquent, il n’y avait pas de variation de la quantité de PCs avec la concentration de Pb à laquelle les algues ont été exposées. La détection et la quantification des PCs ont été faites par chromatographie à haute performance couplée d’un détecteur de fluorescence (HPLC-FL). Tandis que les concentrations métalliques intracellulaires ont été analysées par spectroscopie d’absorption atomique (AAS) ou par spectrométrie de masse à source plasma à couplage inductif (ICP-MS). / In contaminated environments, organisms are often exposed to multiple contaminants at the same time. Based upon the current models for predicting metal effects on organisms (e.g., Biotic Ligand Model, BLM, the free ion model, FIAM), the presence of a second metal is predicted to decrease the bioaccumulation and biological effects of the first. In contrast to this prediction, antagonistic, synergistic and additive effects have been well documented in the literature. Phytochelatins (PCs) are a family of thiol-rich peptides with a general structure (γ-Glu-Cys)n-Gly with n=2-11. PCs are involved in both metal homeostasis and the protection of plants from metal toxicity, through their role as metal chelators. Their synthesis depends upon the metal exposure, the duration of exposure and the biological species involved. Therefore, the objective of this study was to determine, in binary mixtures of metals, if the synthesis of phytochelatins could be predicted using equilibrium models, such as the BLM. The study initially examined binary mixtures: Cd-Ca, Cd-Pb and Cd-Cu by comparing the quantity of internalized metal to the amount of phytochelatins produced by Chlamydomonas reinhardtii in response to a metal stress. The bioaccumulation results, after six hours of exposure, showed that Cd decreased in the presence of Ca and very high concentrations of Pb and Cu. In contrast, it increased in the presence of Cu and remained unchanged in the presence of moderate concentrations of Pb. For mixtures of Cu and Cd, a good correlation was observed between the production of PC2, PC3 and PC4 and the quantity of internalized metals. Both bioaccumulation and phytochelatin synthesis were considered to be synergistic. For mixtures of Cd and Ca, the amount of PC3 and PC4 produced decreased with the internalized metal (antagonistic effect); however, in the presence of added Ca, GSH and PC2 production was much higher than predicted. The detection and quantification of the PCs were performed using an optimized protocol for high performance liquid chromatography coupled with fluorescence detection (HPLC-FL); metal uptake was determined using atomic absorption spectrometry (AAS) or inductively coupled plasma mass spectrometry (ICP-MS).
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Determination of actinide elements in environmental samples by ICP-MSTruscott, Jason Bedford January 2000 (has links)
Methods for the determination of the actinide elements in water, biological, soil and sediment samples have been developed using on-line solid phase extraction and high performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS). Initial applications utilised a commercially available resin, namely TRU-Spec resin, for efficient removal of the matrix prior to elution of uranium and thorium analytes. Comparative analyses of reference materials and natural water samples from Plymouth and Dartmoor demonstrated significant improvement in precision and speed of analysis by using TRU-Spec coupled to ICP-MS compared with alpha spectrometry. Further applications of the TRU-Spec resin for the determination of the transuranic actinide elements neptunium, plutonium and americium, resulted in the successful determination of 239Pu and 237Np in biological reference materials. Detection limits were 700, 850, and 600 attograms (ag) for 237Np, 233Pu, and 241Am, respectively, for a 0.5 ml sample injection, and better than 200 ag/g with 50 ml pre-concentration when sector field (SF) ICP-MS was used. A method for the selective sequential elution of uranium and plutonium was also developed to facilitate the determination of 239Pu without interference due to the 238U1H+ polyatomic ion, caused by high concentrations of 238U in sediment samples. Investigations were performed into the use of a polymeric substrate, which was dynamically coated with chelating dyes such as xylenol orange and 4-(2-pyridylazo) resorcinol, and a silica substrate coated with permanently bonded iminodiacetic acid. The latter was used for the successful determination of uranium and thorium in certified reference material waters. However, the column was found to have a high affinity for iron, making it unsuitable for the determination of the actinides in soil and sediment samples. Subsequently, a polystyrene substrate which was dynamically coated with dipicolinic acid was used for HPLC coupled with SF-ICP-MS. Using this column it was possible to separate the various actinides from each other and from the matrix. In particular, it was possible to separate plutonium and uranium to facilitate interference-free determination of the former. The column also exhibited some selectivity for different oxidation states of Np, Pu and U. Two oxidation states each for plutonium and neptunium were found, tentatively identified as Np(V) and Pu(III) eluting at the solvent front, and Np(IV) and Pu(IV) eluting much later. Detection limits were 12, 8, and 4 fg for 237Np, 239Pu, and 241Am, respectively, for a 0.5 ml injection, and the system was successfully used for the determination of 239Pu in water, biological and soil reference materials.
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Environmental levels of thallium : influence of redox properties and anthropogenic sourcesKarlsson, Ulrika January 2006 (has links)
Thallium is a highly toxic element that humans are exposed to mainly by consumption of drinking water and vegetables grown in soil with high thallium content but also through inhalation of particles in the air. Thallium is also present in fossil fuels, alloys, and in electronic utilities. The increasing use of the element and emissions from notably energy production has lead to a higher load on the surface of the Earth. This study aims at increasing the knowledge about the behaviour of thallium in aquatic environments. Focus has been on the redox chemistry of thallium in relation to its mobility, which is of great importance because Tl(I) and Tl(III) have very different properties in this respect. The relationship between Tl(I) and Tl(III) in surface waters from contaminated and uncontaminated environments was examined by ion chromatography connected on line to ICP-MS (inductively coupled plasma mass spectrometry). It was found in controlled systems that even though Tl(III) is thermodynamically unstable under fresh water conditions Tl(I) was oxidised in the presence of light and iron(III). This was also confirmed in field studies. When lake water samples were exposed to light, Tl(I) was oxidised and thallium was lost from the solution. The most likely explanation for this was adsorption of thallium to particle surfaces. The concentration of thallium in Swedish lakes and soil were measured. In unpolluted lakes the concentration ranges between 4.5-12 ng/l, the sediment concentration was 0.07-1.46 mg/kg. The anthropogenic load was found to have increased since the end of the Second World War although concentrations above background were found since the early industrialisation. In contaminated areas the concentration in soil ranges from 0.64-88 mg/kg, high concentrations were found in systems with alum shale and in soil exposed to runoff from a lead and zinc enrichment plant. The mobilisation of thallium from solid phases in contaminated areas was dependent on pH and about 50% of the leachable content was mobilised already at pH 5-6. Once it had been released to water it was highly mobile. These conditions suggest that in a large part of the Swedish environment a high mobility of thallium can be expected.
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Provenance establishment and authentication of South-East Asian ceramics using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS)Bartle, Emma Kathleen January 2009 (has links)
[Truncated abstract] The sale of fraudulent South-East Asian ceramics constitutes a large proportion of the illegal artefact and antique trade and threatens to undermine the legitimate international market. The sophistication and skill of forgers has reached a level where, using traditional appraisal by eye and hand, even the most experienced specialist is often unable to distinguish between a genuine and fraudulent piece. In addition, the current scientific method of authentication used by the international antiques and art industry, thermoluminescence (TL) dating, carries severe limitations. The technique has an error margin of +/-20 % and requires the removal of a significant piece of the sample being tested, which decreases both the monetary and cultural value of the artefact. Of more concern, forgers have developed methods which produce false test results and which appear to corroborate false claims for the age of artefacts. Consequently, the use of TL dating for authentication of ancient ceramics, especially those of South-East Asian origin, has now come into serious question. The most suitable method for authenticating ceramics is through provenance establishment. Studies published in the literature have investigated the application of various analytical techniques to provide this information for ceramic wares and have highlighted their potential to be used for provenance establishment. However, the value of each of these techniques is limited rendering them generally unsuitable for practical use in the international antiques and art world to authenticate high-value South-East Asian artefacts. Consequently, there is a desperate need for the development of a robust, accurate and non-destructive method which can be practically applied in the industry to authenticate South-East Asian ceramics. ... Minor variations between spectral profiles of artefacts produced in the same country have also been used to further provenance artefacts to a specific production region or kiln site. The results of analyses have been compiled to form a unique reference database which can be added to in the future and used by experts internationally. Adaptation of the developed sampling and analytical methodologies to allow in-situ sampling of large artefacts using the
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Single-cell tracking of therapeutic cells using Laser Ablation-Inductively Coupled Plasma-Mass SpectrometryManagh, Amy J. January 2014 (has links)
Cellular therapy is emerging as a clinically viable strategy in the field of solid organ transplantation, where it is expected to reduce the dependency on conventional immunosuppression. This has produced a demand for highly sensitive methods to monitor the persistence and tissue distribution of administered cells in vivo. However, tracking cells presents significant challenges. In many cases transplanted cells are autologous with the immune system of the transplant recipient, and hence are invisible to typical methods of detection. To enable their differentiation, the cells must be labelled with a suitable, non-toxic and long lifetime label, prior to their administration to patients. In addition, administered cells represent only a small fraction of the recipient's endogenous cells, which necessitates the use of an extremely sensitive detection method. Laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) is an exquisitely sensitive analytical technique, capable of imaging trace elements in complex samples, at high spatial resolution.
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