Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2018-03-12T17:39:30Z No. of bitstreams: 1 Tese Manuel Moreira.pdf: 26683391 bytes, checksum: 22f4cca548ed444677c5428a580b351d (MD5) / Made available in DSpace on 2018-03-12T17:39:30Z (GMT). No. of bitstreams: 1 Tese Manuel Moreira.pdf: 26683391 bytes, checksum: 22f4cca548ed444677c5428a580b351d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ / A acumulação dos elementos-traço nos sedimentos desempenha um importante papel na ciclagem destes elementos nos ambientes marinhos, associado a variáveis formas de retenção no reservatório sedimentar, em diferentes escalas temporais. No presente estudo foi avaliado o fracionamento geoquímico de Fe, Mn, As, Cd, Co, Cr, Cu, Mo, Ni, Pb e Zn entre as frações solúveis em HCl, associada à pirita (FeS2) e associada à fração orgânica, como forma de elucidar os processos que determinam a acumulação destes elementos nos sedimentos da plataforma continental do Sistema de Ressurgência de Cabo Frio (SRCF) nos últimos 8.000 anos. Foi observado que o fracionamento dos elementos Fe, Mn, As, Cr, Ni, Pb e Zn apresenta uma maior proporção na fração solúvel em HCl nos três testemunhos sedimentares coletados ao longo da plataforma continental. O Cu em todas as estações apresentou uma maior proporção na fração da matéria orgânica. O Cd (plataforma interna) e o Pb (plataforma externa) apresentaram uma fração da matéria orgânica importante. O Mo apresentou uma fração pirítica mais importante. O fracionamento geoquímico demonstrou que as formas nas quais os elementos foram acumulados, indicam fortemente influência da diagênese sedimentar. As concentrações de Fe e de S pirítico não foram fatores limitantes no grau de piritização dos elementos-traço. A associação de elementos-traço, tanto à fração ligada à MO quanto à fração ligada à pirita, contribuiu para determinar a retenção de elementos nos sedimentos. Quanto mais intensos foram os processos de re-oxidação do ciclo do S (indicados pela assinatura isotópica da pirita, δ34S), maior foi o grau de piritização do Pb, ao contrário do encontrado para Fe, Cu e Mo, em áreas específicas da plataforma. A estabilização do nível do mar foi o principal evento paleo-oceanográfico determinando a variação vertical da acumulação nos últimos 8.000 anos cal AP, sendo que a variabilidade dos fluxos dos elementos estudados (em relação ao somatório das frações não-detríticas obtidas na extração sequencial) não tendeu a acompanhar a variabilidade do fracionamento geoquímico. Mesmo sob condições oxidantes da coluna d’água, pode ser encontrado um sinergismo da associação à MO e à pirita, contribuindo para determinar a retenção de elementos como Cd, Co, Cu, Mo e Pb nos sedimentos / The accumulation of trace elements in the sediments plays an important role in the cycling of these elements in marine environments, associated with different forms of retention in the sedimentary reservoir, at different time scales. In the present study, the geochemical fractionation of Fe, Mn, As, Cd, Co, Cr, Cu, Mo, Ni, Pb and Zn was evaluated between the fractions soluble in HCl, associated with pyrite (FeS2) and associated with the organic fraction, To elucidate the processes that determine the accumulation of these elements in sediments of the continental shelf of the Cabo Frio Upwelling System (CFUS) in the last 8,000 years. It was observed that the fractionation of the elements Fe, Mn, As, Cr, Ni, Pb and Zn presents a higher proportion in the soluble fraction in HCl in the three sediment cores collected along the continental shelf. Cu in all seasons presented a higher proportion in the fraction of organic matter. The Cd (inner shelf) and the Pb (outer shelf) presented a fraction of the important organic matter. Mo presented a more important pyritic fraction. Geochemical fractionation has shown that the forms in which the elements are being accumulated are strongly influenced by sedimentary diagenesis. The concentrations of Fe and S pyritic were not limiting factors in the degree of piritization of trace elements. The association of trace elements to the fraction bound to the MO and to the fraction bound to pyrite contributed to determine the retention of elements in the sediments. The more intense the S-cycle re-oxidation processes (indicated by the isotopic signature of pyrite, δ34S), the higher the Pb pyritization degree, as opposed to Fe, Cu and Mo, in specific areas of the shelf. The stabilization of the sea level was the main paleo-oceanographic event determining the vertical variation of the accumulation in the last 8,000 years BP. The variability of the fluxes of the elements studied (in relation to the sum of the non-detrital fractions obtained in the sequential extraction) did not tend to follow the variability of the geochemical fractionation. Even under oxidizing conditions of the water column, a synergism of the association with OM and pyrite can be found, contributing to determine the retention of elements such as Cd, Co, Cu, Mo and Pb in the sediments

Foi desenvolvido um programa computacional escrito na linguagem de programação C++ denominado CALFRAC para quantificar o processo de cristalização fracionada em sistemas ígneos, utilizando para isso as concentrações dos elementos maiores, menores e traços. O algoritmo moderniza, torna mais eficiente e aprimora os programas publicados na literatura e possui a grande vantagem de poder calcular, automaticamente, todas as possíveis combinações de evolução das amostras envolvidas na diferenciação, além de associar aos cálculos os elementos-traço, os quais servem para confirmar os resultados sugeridos pelos ajustes dos elementos maiores e menores. O CALFRAC calcula a fração total subtraída do magma inicial e as frações referentes a cada mineral fracionado através do cálculo do balanço de massa, utilizando as concentrações de elementos maiores e menores, empregando os métodos de estimativa de máxima verossimilhança e dos multiplicadores de Lagrange para a resolução por mínimos quadrados, enquanto para os elementos-traço o programa utiliza a Equação de Rayleigh. Em ambos os casos a média dos erros percentuais relativos é usada como indicação das melhores evoluções. O programa CALFRAC foi aplicado na investigação da possibilidade de diferenciação por cristalização fracionada em amostras de soleiras de diabásio da Bacia do Paraná, que ocorrem nos municípios de Salto do Itararé, Ponta Grossa, Prudentópolis, Rebouças, Irati, Reserva e Jaguariaíva (PR), as quais foram coletadas para essa finalidade. Nas 33 amostras coletadas foram realizadas determinações de elementos maiores, menores e traços, incluindo terras raras, empregando-se os métodos de Fluorescência de Raios X e Ativação Neutrônica. Os resultados fornecidos pelo programa foram insatisfatórios, não sendo possível estabelecer um percurso de diferenciação das rochas mais primitivas para as mais diferenciadas das intrusões, devido ao fato de que provavelmente muitas das amostras analisadas representam a mistura de magmas com porções contendo acumulação de fases minerais causada pelo próprio processo de cristalização fracionada in situ. / CALFRAC is a computer program written in C++ programming language developed to quantify fractional crystallization processes in igneous systems. Major, minor and trace element concentrations are used as input for calculations. The new algorithm enhances and makes the program more efficient than those published in the literature. Besides it is capable to automatically calculating all possible rock sample combinations involving differentiation by fractional crystallization process, using in addition trace element concentrations to corroborate the results obtained by the fitting of major and minor element abundances. CALFRAC calculates the total fraction subtracted from the original magma and the percentage of each fractionated mineral by solving least-squares mass balance equations based on major and minor element concentrations. The methods of maximum likelihood estimate and Lagrange multipliers are used to solve the equations, whereas for the quantification of trace elements the program uses the Rayleigh Equation. In both cases the mean relative percentage errors is used as an indication of the best results. The program CALFRAC was applied to investigate the possibility of differentiation by fractional crystallization of diabase samples from Paraná Basin sills, which outcrop nearby Salto do Itararé, Ponta Grossa, Prudentópolis, Rebouças, Irati, Reserva and Jaguariaíva towns (PR). The 33 collected samples were analyzed for major, minor and trace elements, including rare earths, employing X-Ray Fluorescence and Neutron Activation methods. The program output was not satisfactory, since it was not possible to establish a differentiation sequence from the more primitive to the more differentiated rocks of the intrusions. This is probably due to the fact that many rock samples are the result of mixing of magmatic melts with mineral accumulation zones, which were formed by the in situ fractional crystallization process.

Cette thèse a pour objectifs de documenter les variations spatiotemporelles de la zone de minimum d’oxygène (OMZ) du Pacifique Nord-Est, et d’identifier les mécanismes qui ont causé ces variations. L’étude est fondée sur l’analyse géochimique des composants majeurs, mineurs et traces de sédiments prélevés dans le Pacifique Nord-Est, en combinant des mesures par ICP-MS et scanneur XRF. Ces mesures ont permis de distinguer l’effet de la productivité biologique de celui de la ventilation océanique sur l’oxygénation du sédiment. J’ai pu mettre en évidence le rôle prépondérant de la productivité au niveau de la Basse Californie (23°N), qui varie en phase avec les températures en Atlantique Nord durant les 120.000 dernières années. Par ailleurs, la ventilation océanique a probablement joué un rôle important au niveau du golfe de Papagayo (12°N), par l’advection de masses d’eau provenant des hautes latitudes nord et sud. L’intensité de l’OMZ du Pacifique Nord-Est serait donc influencée par des modifications des circulations océaniques et atmosphériques, liées aux climats des hautes latitudes des deux hémisphères. / This thesis aims at documenting the spatiotemporal variations of the Oxygen Minimum Zone (OMZ) of the northeastern Pacific, and identifying the mechanisms that caused theses variations. The study is based on the geochemical analyses of major, minor, and trace elements of sediments from the northeastern Pacific, by combining ICP-MS and XRF scans measurements. These measurements allowed distinguishing the effect of biologic productivity and oceanic ventilation on sediment oxygenation. I was able to highlight the predominant impact of the productivity off the Baja California Margin (23°N), which varied in phase with the high northern Atlantic temperature across the past 120,000 years. Moreover, oceanic ventilation did play an important role off the Papagayo Gulf (12°N), because of the advection of water mass coming from the high northern and southern latitudes. OMS intensity in the northeastern Pacific could thus be influenced by changes in the atmospheric and oceanic circulation, in relation to high northern and southern latitudes climates.

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Dans cette thèse nous avons simulé la distribution d’éléments traces en Méditerranée, dans le but de mieux contraindre la circulation thermohaline et les cycles biogéochimiques. Pour cela, nous avons utilisé le modèle dynamique à haute résolution NEMO-MED12 couplé avec le modèle de biogéochimie marine PISCES.La Méditerranée offre un cadre particulièrement attrayant pour l’étude des traceurs géochimiques. Il s’agit d’une mer semi-fermée, ce qui permet de mieux contraindre les différentes sources et puits des éléments (poussières atmosphériques, fleuves …). Plus particulièrement, nous avons modélisé le tritium (3H), traceur transitoire couramment utilisé pour l’étude de la variabilité interannuelle de la circulation thermohaline. Nous avons aussi simulé les isotopes de l’hélium (3He, 4He), traceurs conservatifs injectés par l’activité volcanique sous-marine et les sédiments, pour contraindre la circulation profonde. Nous nous sommes intéressés également à la composition isotopique du Néodyme (Nd), traceur permettant d’étudier les échanges de matière avec les marges continentales, ainsi qu’à la modélisation du radiocarbone (14C), qui permet d’avoir des informations uniques sur les variations de la circulation thermohaline et des processus de mélange sur les périodes récentes et passées.Cette ensemble de simulations nouvelles et la confrontation avec des observations récentes d’éléments traces issues de différents programmes d’observation (GEOTRACES, METEOR, PALEOMEX), a apporté une expertise nouvelle et supplémentaire sur la dynamique et les cycles biogéochimique en mer Méditerranée. Ce travail contribue à améliorer le modèle régional NEMO/Med12/PISCES développé pour ce bassin, apporte une expertise essentielle pour développer notre aptitude à prévoir l’évolution future de ce bassin sous la pression du changement anthropique. / Useful diagnostics of the ventilation of the ocean’s interior are derived from geochemical tracers characterized by simple boundary conditions at the ocean’s surface, and a conservative behavior in marine waters. In this thesis, we simulated explicitly some trace elements distribution in the Mediterranean to better constrain the thermohaline circulation and biogeochemical cycles. We used a high resolution physical/biogeochemical model NEMO-MED12-PISCES.The Mediterranean offers a particularly attractive setting for studying geochemical tracers. It’s a semi-enclosed basin, which makes it easier to quantify the various sources and sinks of the elements (atmospheric dust, rivers ...). In particular, we modeled tritium (3H), a transient tracer currently used for the study of the interannual variability of the thermohaline circulation. We also simulated helium isotopes (3He, 4He), useful tracers for investigating the deep ocean circulation.We have simulated the isotopic composition of neodymium (Nd), tracer adapted to investigate the exchanges between dissolved/particulate phases, with the continental margins, and to constrain the modern and paleo thermohaline circulation, as well as radiocarbon (14C), an ideal tracer for studying air-sea gas exchange and for assessing the ventilation rate of the deep water masses over very long timescales.This study is part of the work carried out to assess the robustness of the NEMO-MED12 model, which will be used to study the evolution of the climate and its effect on the biogeochemical cycles in the Mediterranean Sea, and to improve our ability to predict the future evolution of the Mediterranean Sea under the increasing anthropogenic pressure.

No description available.

No description available.

Les métaux et les métalloïdes sont naturellement présents dans l’ensemble de la biosphère et les premières formes de vie ont su bénéficier des plus abondants comme macronutriments. Catégorisés dans le tableau périodique des éléments selon leurs caractéristiques chimiques, les métaux sont également divisés en deux grandes catégories : les métaux essentiels et non essentiels. Se retrouvent parmi les métaux essentiels, le sélénium, le calcium et le zinc, nécessaires aux fonctionnements cellulaires tandis que le cadmium, le plomb et le mercure sont des exemples de métaux dits non essentiels puisqu’ils ne sont pas requis pour les fonctions biologiques. Cependant, peu importe leur essentialité, les métaux peuvent engendrer des effets délétères lorsque leur concentration intracellulaire dépasse un certain seuil, propre à la nature chimique, ou spéciation, de chaque métal et de la tolérance de chaque organisme. Si la toxicité d’un métal dépend de sa spéciation, sa spéciation est également dépendante des conditions du milieu, qu’il soit aquatique ou cellulaire. De plus, la spéciation d’un métal est déterminante de sa biodisponibilité, et donc, de sa bioaccumulation. Considérant que les activités anthropiques et les points de sources naturelles ponctuels contribuent à la remobilisation et à l’augmentation des concentrations de métaux dans les écosystèmes, notamment les milieux aquatiques, déterminer la spéciation des métaux afin de mieux prédire leur biodisponibilité et leur bioaccumulation par les organismes est essentiel. L‘objectif général de cette thèse est d’étudier, par l’entremise de trois modèles d’organismes aquatiques, la bioaccumulation des métaux à l’interface rivière-estuaire, leur gestion intracellulaire et, plus particulièrement pour le mercure, son effet toxicologique suivant sa distribution subcellulaire. Dans un premier temps, nous avons mené une étude sur les facteurs biogéochimiques influençant la distribution et la bioaccumulation du mercure et des éléments de terres rares par la mye commune (Mya arenaria) à l’embouchure de la rivière Romaine et Mingan dans la région de la Côte-Nord au Québec. Nous avons également mesuré les concentrations d’éléments traces essentiels et d’autres métaux non essentiels dans une perspective d’évaluation du risque et des bénéfices à la consommation de cette espèce pour quatre groupes de population. Par la signature isotopique de soufre des myes, nos résultats ont démontré que les myes influencées par les eaux marines accumulaient des concentrations plus faibles de mercure total, de méthylmercure et de terres rares. Nous avons observé que la matière organique des sédiments joue un rôle dans la rétention du mercure total et du méthylmercure dans ce compartiment tandis que les éléments de terres étaient davantage liés à la concentration de fer. Nous avons également identifié les sédiments comme un compartiment de transfert de ces métaux vers les myes. En ce qui a trait à l’évaluation du risque à la consommation, à la suite de la comparaison des concentrations de métaux non essentiels à des valeurs de référence, la consommation des myes de tous les secteurs à l’étude ne pose pas de risque pour la santé des consommateurs.trices. En contrepartie, l’évaluation de l’apport nutritionnel a indiqué que les myes présentent une source élevée en fer et en sélénium et que leur consommation est recommandée. Dans un second temps, nous avons évalué la gestion intracellulaire de métaux selon leurs caractéristiques chimiques dans le foie de la perchaude (Perca flavescens) du lac Saint-Pierre, une espèce de poisson exposée chroniquement à de faibles concentrations polymétalliques. Par l’entremise de résultats suivant l’approche de fractionnement subcellulaire, nous avons démontré des profils de distribution subcellulaire distincts entre les métaux selon leur classification chimique. Les métaux de classe A et intermédiaires étaient préférentiellement associés aux fractions sensibles. Nos résultats ont démontré une distribution subcellulaire divergente entre le méthylmercure, le cadmium et le cuivre. Contrairement au cadmium et au cuivre qui sont associés à la fraction protéines thermosensibles du cystosol (HSP), le méthylmercure est davantage lié aux fractions sensibles. Finalement, une comparaison des proportions de méthylmercure, de cuivre et de cadmium entre la perchaude et d’autres espèces de poissons a permis de confirmer que les métaux se distribuent dans le milieu intracellulaire en raison de leur affinité et sans égard à la bioaccumulation, réfutant ainsi le principe de débordement subcellulaire. Finalement, nous avons lié la distribution subcellulaire du méthylmercure dans le foie du grand brochet (Esox lucius) d’une sous-section de la rivière Saint-Maurice à un marqueur de stress oxydant. Considérant le foie total, nos résultats ont permis de corréler les concentrations de méthylmercure et de sélénium à une augmentation de la peroxydation des lipides dans le foie. Cette relation soulève un intérêt afin d’approfondir les connaissances sur les mécanismes cellulaires pouvant exacerber les effets conjoints potentiels entre le méthylmercure et le sélénium. De plus, nous avons observé une corrélation positive entre la concentration de méthylmercure associée à la fraction mitochondriale et l’augmentation de la peroxydation des lipides dans le foie, jusqu'alors indéterminée. Les résultats de cette thèse mettent en lumière la pertinence et la nécessité de considérer la spéciation des métaux, leur bioaccumulation et leur distribution subcellulaire dans l’évaluation de leurs effets indésirables, puisque ces processus sont intrinsèquement liés. / Metals and metalloids are naturally present throughout the biosphere and the first forms of life were able to benefit from the most abundant as macronutrients. Categorized in the periodic table of elements according to their chemical characteristics, metals are also divided into two main categories: essential and non-essential metals. Among the essential metals are selenium, calcium, and zinc, necessary for cellular functions, while cadmium, lead and mercury are examples of so-called non-essential metals since they are not required for biological functions. However, regardless of their essentiality, metals can cause deleterious effects when their intracellular concentration exceeds a certain threshold, specific to the chemical nature, or speciation, of each metal and the tolerance of each organism. If the toxicity of a metal depends on its speciation, its speciation is also dependent on the conditions of the environment, whether aquatic or cellular. Moreover, the speciation of a metal determines its bioavailability, and therefore, its bioaccumulation. Considering that anthropogenic activities and point natural sources contribute to the remobilization and increase of metal concentrations in ecosystems, especially aquatic environments, assessing the speciation of metals to better predict their bioavailability and their bioaccumulation by organisms is essential. The general objective of this thesis is to study, through three models of aquatic organisms, the bioaccumulation of metals at the river-estuary interface, their intracellular handling and, in particular for mercury, its toxicological effect according to its subcellular distribution. First, we conducted a study on the biogeochemical factors influencing the distribution and bioaccumulation of mercury and rare earth elements by the soft-shell clam (Mya arenaria) at the mouth of the Romaine and Mingan rivers in the Côte-Nord region of Quebec. We also measured the concentrations of essential trace elements and other non-essential metals to assess health concerns and nutritional benefits for four population subgroups. Through the isotopic sulfur signature of clams, our results demonstrated that clams influenced by marine waters accumulated lower concentrations of total mercury, methylmercury, and rare earth elements. We observed that organic matter plays a role in the retention of total mercury and methylmercury in sediments whilst the retention of rare earth elements was more related to the iron concentration in sediments. We have also identified sediments as a transfer compartment of these metals to clams. Considering the health risk and benefits following the consumption of soft-shell clams, the comparison of the concentrations of non-essential metals with reference values for food safety, showed that their consumption should not pose a health risk to the consumer. On the other hand, the evaluation of the nutritional intake indicated that clams are a high source of iron and selenium. Second, we evaluated the intracellular management of metals according to their chemical characteristics in the liver of yellow perch (Perca flavescens) from Lake Saint-Pierre, a species of fish chronically exposed to low polymetallic concentrations. Through results following the subcellular partitioning approach, we demonstrated distinct subcellular distribution patterns between metals according to their chemical classification. Class A and intermediate metals were preferentially associated with metal-sensitive fractions. Our results showed a divergent subcellular distribution between methylmercury, cadmium, and copper. Unlike cadmium and copper which are associated with the heat-stable protein (HSP) fraction, methylmercury was bound to the metal-sensitive fractions. Finally, a comparison of the proportions of methylmercury, copper, and cadmium between yellow perch and other species of fish confirmed that metals distribute in the intracellular environment due to their chemical affinity and regardless of the bioaccumulation level, thus refuting the principle of the spillover effect. Finally, we linked the subcellular distribution of methylmercury in the liver of northern pike (Esox lucius) from a subsection of the Saint-Maurice River to an oxidative stress biomarker. Considering the total liver, our results correlated methylmercury and selenium concentrations with an increase in lipid peroxidation in the whole liver. This relationship raises the interest to deepen our knowledge on the cellular mechanisms that can exacerbate the potential joint effects of methylmercury and selenium. Moreover, among the subcellular fractions, we observed a positive correlation between the concentration of methylmercury associated with the mitochondrial fraction and the increase of lipid peroxidation in the whole liver, which was hitherto undetermined. The results of this thesis highlight the relevance and the need to consider the speciation of metals, their bioaccumulation, and their subcellular distribution in the assessment of their adverse effects, since these processes are intrinsically linked.

Einleitung: Mangan (Mn) ist ein essentielles Spurenelement, welches als integraler Bestandteil von Metalloenzymen oder als Kofaktor zahlreiche Stoffwechselprozesse katalysiert. Häufig wird der Versorgungsstatus von Pferden über eine Blutanalyse im Serum überprüft, obwohl wissenschaftlich belegte Referenzbereiche für Pferde bislang nicht etabliert wurden. Es liegen für Pferde kaum Untersuchungen vor, die Effekte einer Supplementierung bei definierter Mn-Aufnahme betrachtet haben. In der Literatur finden sich im Allgemeinen nur wenige Untersuchungen zu Mn bei Pferden. Ziel der Studie: Das Ziel dieser Untersuchung war die Etablierung von Mn-Referenzintervallen für adulte Warmblutpferde im Plasma, Serum und Vollblut sowie die Überprüfung von Effekten einer oralen Mn-Supplementierung mit unterschiedlichen Verbindungen (organisch vs. anorganisch) auf die Mn-Konzentrationen im Blut und in der Milch von Stuten und auf die Mn-Blutkonzentrationen von deren Saugfohlen. Tiere, Material und Methoden: Für die Referenzwerterhebung wurden von 270 gesunden, adulten Warmblutpferden im Alter von 3-25 Jahren einmalig Blutproben gewonnen, um im Lithium Heparin (LH)-Plasma, Serum und Vollblut die Mn-Konzentration mittels Atomabsorptionsspektrometrie (AAS) und Massenspektrometrie mit induktiv gekoppeltem Plasma (ICP-MS) zu analysieren. Zeitgleich entnommene Futterproben ermöglichten die Bestimmung des Mn-Gehaltes der korrespondierenden Fütterung. In eine 90-tägige, randomisierte, placebo-kontrollierte Supplementierungsphase wurden 33 laktierende Stuten und deren Saugfohlen einbezogen und in drei Fütterungsgruppen (Placebo n = 11, MnChelat n = 11, MnSulfat n = 11) eingeteilt. Zusätzlich zur Basisration (Heu ad libitum, Mischration: Mn-Aufnahme ca. 100 mg/kg Trockenmasse (TM)) erhielten die Stuten täglich 200 g eines Ergänzungsfutters entweder als Placebo oder mit 560 mg Mn als Mn-Sulfat oder Mn-Chelat zugesetzt. Blut- und Milchanalysen wurden mittels ICP-MS an 14-tägig gewonnenen Proben von Stuten und Fohlen durchgeführt. Die Daten wurden unter Verwendung der kommerziellen Software Statistica®, IBM SPSS Statistics 27 und XLSTAT statistisch ausgewertet. Die Referenzintervalle wurden nach den Empfehlungen des Clinical and Laboratory Standards Institute und der International Federation of Clinical Chemistry and Laboratory Medicine berechnet, wonach sie den Bereich zwischen 2,5. und 97,5. Perzentil der analysierten Mn-Konzentrationen umfassen. Ein Methodenvergleich für die AAS und ICP-MS erfolgte mittels Passing-Bablok-Regression. Daten aus der Mn-Supplementierungsstudie wurden mittels des Shapiro-Wilks-Testes auf Normalverteilung überprüft. Die Daten waren nicht normalverteilt, sodass Tests für nicht-parametrische Daten angewendet wurden. Das Signifikanzniveau lag bei p < 0,05. Die Darstellung der Daten erfolgt als Median und dem 25./75. Perzentil. Ergebnisse: Die Mn-Aufnahme (587 – 1702 mg/Tag) war bei allen Pferden deutlich höher als die Mn-Versorgungsempfehlung von 485-545 mg/Tag. Die Pferde zeigten bei der Referenzwerterhebung im Vollblut mit medianen Mn-Konzentrationen von 12,4 µg/l (Interquartilsbereich: 9,10-16,1 µg/l) signifikant höhere Mn-Werte (p < 0,0001) als im korrespondierenden Serum (Median: 1,65 µg/l; Interquartilsbereich: 1,39-1,95 µg/l) oder LH-Plasma (Median: 1,35 µg/l; Interquartilsbereich: 1,01-1,71 µg/l). Diese Ergebnisse ließen sich auch durch die Supplementierungsstudie bestätigen. Die Stuten wiesen im Vollblut (Median: 15,6 µg/l; Interquartilsbereich: 12,8 - 18,5 µg/l) zehnfach höhere Mn-Konzentrationen als im Serum (Median: 1,54 µg/l; Interquartilsbereich: 1,20 - 1,90 µg/l) auf. Auch die Fohlen wiesen 16,4-fach höhere Mn-Konzentrationen im Vollblut (Median: 21,3 µg/l; Interquartilsbereich: 16,7 - 28,1 µg/l) im Vergleich zum Serum (Median: 1,50 µg/l; Interquartilsbereich: 1,30 - 1,70 µg/l) auf. Die Mn-Vollblutspiegel der Fohlen entsprachen der 1,6-fachen Mn-Konzentration ihrer Mutterstuten und unterschieden sich signifikant (p < 0,01). Die Milch enthielt mediane Mn-Konzentrationen von 0,012 mg/kg. Die Mn-Supplementierung hatte keinen Effekt auf die Mn-Spiegel in der Milch oder im Blut von Stuten und deren Fohlen. Im Methodenvergleich ergaben sich für LH-Plasma und Serum zwischen der AAS und der ICP-MS statistisch signifikante Abweichungen in den Mn-Bestimmungen, wohingegen beide Verfahren für das Vollblut vergleichbare Ergebnisse lieferten. Schlussfolgerung: Vollblut zeigt durchschnittlich 10-fach höhere Mn-Konzentrationen als Serum oder LH-Plasma. Bei der Bewertung von Mn-Konzentrationen im Blut muss daher beachtet werden, welches Probenmaterial analysiert wurde und welche Methode angewandt wird, da es zwischen AAS und ICP-MS in Serum und Plasma zu relevanten Unterschieden kommen kann. Die Mn-Supplementierung beeinflusste die Mn-Konzentrationen im Blut nicht. Darüber hinaus waren die Mn-Spiegel im Vollblut der Fohlen im Vergleich zu den Stuten höher, obwohl die Mn-Konzentrationen unabhängig von der Supplementierung in der Stutenmilch niedrig waren. Aufgrund des geringen Mn-Gehaltes in der Milch ist eine frühzeitige Mn-Ergänzung, vorzugsweise über Raufutter notwendig, um die Mn-Versorgung der Fohlen sicherzustellen. Die kalkulierte Mn-Aufnahme der Pferde in dieser Studie zeigt, dass aufgrund der hohen Mn-Gehalte im Raufutter ein Mn-Mangel in der Praxis selten vorkommt.:Inhaltsverzeichnis Seite 1 Einleitung 1 2 Literaturübersicht 2 2.1 Vorkommen und chemische Eigenschaften von Mangan 2 2.2 Manganstoffwechsel 3 2.2.1 Absorption und Verdaulichkeit 3 2.2.2 Transport im Blut 3 2.2.3 Retention und Speicherung 4 2.2.4 Exkretion 4 2.3 Funktionen von Mangan im Stoffwechsel 5 2.3.1 Modulation von oxidativem Stress 5 2.3.2 Kohlenhydratstoffwechsel 5 2.3.3 Fettstoffwechsel 6 2.3.4 Harnstoffsynthese 6 2.3.5 Fruchtbarkeit und Reproduktion 7 2.3.6 Knorpel- und Knochenstoffwechsel 7 2.4 Manganmangel 7 2.5 Toxizität von Mangan 8 2.6 Mangan in der Pferdefütterung 9 2.6.1 Manganbedarf von Pferden 9 2.6.2 Manganversorgung von Stute und Fohlen 10 2.6.3 Mangangehalte in pferdetypischen Futtermitteln 10 2.6.3.1 Native Mangangehalte in Futtermitteln 10 2.6.3.2 Rechtliche Grundlagen zur Manganergänzung 11 2.6.3.3 Manganverbindungen zur Ergänzung 12 2.7 Diagnostik der Manganversorgung 12 2.7.1 Referenzintervalle 12 2.7.2 Blut 13 2.7.2.1 Plasma und Serum 13 2.7.2.2 Vollblut 13 2.7.3 Haar 14 2.7.4 Leber und andere Gewebe 14 2.7.5 Mangan-abhängige Superoxid-Dismutase 15 3 Publikationen 16 3.1 Mangankonzentrationen im Vollblut, Plasma und Serum adulter Warmblutpferde an drei Standorten in Deutschland 16 3.2 Effekte einer oralen Mangan-Supplementierung mit unterschiedlichen Verbindungen auf die Mangan-Vollblut- und Serumkonzentrationen von Stuten und Saugfohlen 32 4 Diskussion 45 4.1 Manganreferenzintervalle im Blut und Supplementierungseffekte 45 4.2 Diagnostik in der Praxis 48 4.3 Schlussfolgerungen 49 5 Zusammenfassung 50 6 Summary 52 7 Literaturverzeichnis 54 8 Anhang 65 8.1 Liste der Kongressbeiträge im Rahmen dieser Arbeit 65 8.2 Sonstige Kongressbeitrage 65 9 Danksagung 66 / Introduction: Manganese (Mn) is an essential trace element that catalyzes numerous metabolic processes as an integral component of metalloenzymes or as a cofactor. The supply status of horses is often monitored by means of blood serum analysis, although scientifically proven reference ranges for horses have not yet been established. There are only limited studies available for horses that have examined the effects of supplementation with a defined Mn intake. In general, there are only few studies on Mn in horses in the literature. Aim of the study: The aim of this study was to establish Mn reference intervals for adult warm-blooded horses in plasma, serum and whole blood and to investigate the effects of oral Mn supplementation with different compounds (organic vs. inorganic) on the Mn concentrations in the blood and milk of mares and the Mn concentrations in the blood of their suckling foals. Animals, material and methods: For the reference value survey, blood samples were taken once from 270 healthy, adult warm-blooded horses aged 3-25 years in order to determine the Mn concentration in lithium heparin (LH) plasma, serum and whole blood by means of atomic absorption spectrometry (AAS) and inductively coupled plasma mass spectrometry (ICP-MS). Accompanying feed samples were taken to confirm the Mn content of the corresponding feed. In a 90-day, randomized, placebo-controlled supplementation phase, 33 lactating mares and their suckling foals were included and divided into three feeding groups (placebo n = 11, MnChelat n = 11, MnSulfat n = 11). In addition to the routine ration (hay ad libitum, mixed ration: Mn intake approx. 100 mg / kg dry matter), the mares received 200 g of a supplementary feed daily either as a placebo or with 560 mg of Mn added as Mn sulfate or Mn chelate. Blood and milk analysis were performed using ICP-MS on samples taken from mares and foals biweekly. All data were statistically assessed with commercial software packages (Statistica®, IBM SPSS Statistics 27, XLSTAT). The reference intervals were calculated according to the recommendations of the Clinical and Laboratory Standards Institute and the International Federation of Clinical Chemistry and Laboratory Medicine, according to which they range between 2.5. and 97.5. percentile of the analyzed Mn concentrations. A comparison of methods for AAS and ICP-MS was carried out using Passing-Bablok regression. Data from the Mn supplementation study were checked for normal distribution using the Shapiro-Wilks test. As the data were not normally distributed, tests for non-parametric data were subsequently used for analyses. Level of significance was set at p < 0.05. Data are presented as median and 25. /75. percentile. Results: In all horses Mn intake (587-1702 mg/day) was significantly higher than the current recommendations for Mn supply (485-545 mg/day). Analyses verified significantly (p < 0.0001) higher Mn whole-blood concentrations in horses (median 12.4 µg/L; interquartile range: 9.10-16.1 µg/L) than in the corresponding serum (median: 1.65 µg/L; interquartile range: 1.39-1.95 µg/L) or LH plasma (median: 1.35 µg/L; interquartile range: 1.01-1.71 µg/L). These results could also be confirmed by the supplementation study. The mares showed 10-fold Mn concentrations in whole blood (median: 15.6 µg/L; interquartile range: 12.8-18.5 µg/L) compared to the serum (median: 1.54 µg/L; interquartile range: 1, 20-1.90 µg/L). The foals also had Mn whole blood concentrations 16.4 times higher (median: 21.3 µg/L; interquartile range: 16.7-28.1 µg/L) compared to the serum Mn concentrations (median: 1.50 µg/L; interquartile range: 1.30-1.70 µg/L). Additionally, Mn whole blood levels of the foals corresponded to 1.6 times the Mn concentration of their dams and thus differed significantly (p < 0.01). The milk contained median Mn concentrations of 0.012 mg/kg. Mn supplementation had no effect on Mn levels in milk or blood of mares and their foals. A comparison of methods showed statistically significant deviations in the Mn determinations for LH plasma and serum between the AAS and the ICP-MS, whereas they provided comparable results for whole blood. Conclusion: Whole blood shows an average of 10 times higher Mn concentrations than serum or LH plasma. When evaluating Mn concentrations, it must therefore be taken into consideration which sample material is analyzed and which method is used, as relevant differences were found between AAS and ICP-MS in serum and plasma. Blood Mn concentrations were not affected by the Mn supplementation. However, the Mn levels differed significantly between serum and whole blood. In addition, the Mn concentrations in whole blood of suckling foals were higher compared to their dams, although the Mn concentrations in the mare's milk were low regardless of the supplementation. Due to low Mn content in milk, early Mn supplementation, preferably by forages, is necessary to ensure that foals are supplied with Mn according to their requirement. The calculated Mn intake of the horses in this study shows that due to the high Mn content in roughage, Mn deficiency rarely occurs in practice.:Inhaltsverzeichnis Seite 1 Einleitung 1 2 Literaturübersicht 2 2.1 Vorkommen und chemische Eigenschaften von Mangan 2 2.2 Manganstoffwechsel 3 2.2.1 Absorption und Verdaulichkeit 3 2.2.2 Transport im Blut 3 2.2.3 Retention und Speicherung 4 2.2.4 Exkretion 4 2.3 Funktionen von Mangan im Stoffwechsel 5 2.3.1 Modulation von oxidativem Stress 5 2.3.2 Kohlenhydratstoffwechsel 5 2.3.3 Fettstoffwechsel 6 2.3.4 Harnstoffsynthese 6 2.3.5 Fruchtbarkeit und Reproduktion 7 2.3.6 Knorpel- und Knochenstoffwechsel 7 2.4 Manganmangel 7 2.5 Toxizität von Mangan 8 2.6 Mangan in der Pferdefütterung 9 2.6.1 Manganbedarf von Pferden 9 2.6.2 Manganversorgung von Stute und Fohlen 10 2.6.3 Mangangehalte in pferdetypischen Futtermitteln 10 2.6.3.1 Native Mangangehalte in Futtermitteln 10 2.6.3.2 Rechtliche Grundlagen zur Manganergänzung 11 2.6.3.3 Manganverbindungen zur Ergänzung 12 2.7 Diagnostik der Manganversorgung 12 2.7.1 Referenzintervalle 12 2.7.2 Blut 13 2.7.2.1 Plasma und Serum 13 2.7.2.2 Vollblut 13 2.7.3 Haar 14 2.7.4 Leber und andere Gewebe 14 2.7.5 Mangan-abhängige Superoxid-Dismutase 15 3 Publikationen 16 3.1 Mangankonzentrationen im Vollblut, Plasma und Serum adulter Warmblutpferde an drei Standorten in Deutschland 16 3.2 Effekte einer oralen Mangan-Supplementierung mit unterschiedlichen Verbindungen auf die Mangan-Vollblut- und Serumkonzentrationen von Stuten und Saugfohlen 32 4 Diskussion 45 4.1 Manganreferenzintervalle im Blut und Supplementierungseffekte 45 4.2 Diagnostik in der Praxis 48 4.3 Schlussfolgerungen 49 5 Zusammenfassung 50 6 Summary 52 7 Literaturverzeichnis 54 8 Anhang 65 8.1 Liste der Kongressbeiträge im Rahmen dieser Arbeit 65 8.2 Sonstige Kongressbeitrage 65 9 Danksagung 66

This master's thesis covers an investigation of the reduction behavior of different iron oxides when electrolytically reduced with molten salt electrolysis (MSE). The tested iron oxides were wüstite (FeO), hematite (Fe2O3), magnetite (Fe3O4) and magnetite ore concentrate from the Tapuli deposit in Pajala, Norrbotten, Sweden. The properties of the Tapuli magnetite ore and magnetite ore concentrate were analysed from a mineralogical perspective to evaluate how the raw ore material influences the concentrate and its reduction by the MSE technology. The electrolytic experiments were performed in an Inconel 625 cell body within a pit-furnace. The different iron oxides were tested separately. The reduction samples were constructed of one or three iron oxide briquettes of 20 g each within a molybdenum mesh attached on a molybdenum tray with molybdenum wires. The molten electrolyte was kept at 500°C with an applied voltage of 1.7 or 2.1 V. The used electrolyte was sodium hydroxide (NaOH). The mineralogical examination shows that the Tapuli ore varies in composition between different locations of the deposit with respect to magnetite grain size and skarn composition and grain size. Point analyses with Laser Ablation Single Collector Inductively Coupled Plasma Mass Spectrometry (LA-SC-ICP-MS) on magnetite grains in thin sections from five drill cores fromdifferent parts of the deposit show that the element composition in the magnetite grains vary between the samples. Core-to-rim analyses for Fe, Mg, Mn and Al reveal relatively homogenous grades throughout the grains, with a few exceptions. Phase analysis with XRD shows that reduction has occurred in all tested iron oxides. Without prevention, the reduction products from trials on Fe2O3, Fe3O4 and magnetite ore concentrate show distinct XRD peaks of the by-product NaFeO2. According to XRD, the addition of Na2O seems to have reduced the NaFeO2 formation. Interestingly, no NaFeO2 was formed in the FeO trials. This might be explained by the absence of Fe3+ in FeO. The variation of the current-time curves of the trials is interpreted to depend on the voltage applied, the number of briquettes, briquette decomposition and Na2O addition. Electrolysis in molten NaOH can be used to reduce iron oxides. Despite this, NaOH might not be a suitable electrolyte for this process due to its interaction with Fe2O3 and Fe3O4 resulting information of NaFeO2. Na2O can be used as an additive to prevent formation of NaFeO2 but sharply decreases the current response, thus having an apparent negative effect on the process efficiency. Another preventive measure that can be tested is to calibrate the process voltage to decompose the NaFeO2 but not NaOH. Due to the shown interaction tendency of NaOH, other electrolytes should however be considered for this process. Regarding the Tapuli ore concentrate, more tests are needed to draw conclusions about how the trace elements effects its electrolytic behavior. / Denna masteruppsats avhandlar en undersökning av reduktionsbeteendet hos olika järnoxider vid elektrolytisk reduktion i saltsmälta (molten salt electrolysis (MSE)). Järnoxiderna som har testats är wüstit (FeO), hematit (Fe2O3), magnetit (Fe3O4) och magnetitmalmkoncentrat från malmfyndigheten Tapuli i Pajala, Norrbotten, Sverige. Malmkoncentratets egenskaper har analyserats ur mineralogisk synvinkel för att utvärdera hur den råa malmens mineralogi påverkar koncentratet och dess reduktionsbeteende vid elektrolys i saltsmälta. Elektrolysexperimenten utfördes i cellkropp av Inconel 625 placerad i en gropugn. De olika järnoxiderna testades separat. Reduktionsproverna utgjordes av en eller tre järnoxidbriketter på 20 g inuti ett molybdennät, fastvirade på en molybdenbricka med molybdentråd. Den smälta elektrolyten hölls vid en temperatur av 500°C med en applicerad spänning av 1.7 eller 2.1 V. Elektrolyten som användes var natriumhydroxid (NaOH). Den mineralogiska undersökningen visar att tapulimalmens sammansättning varierar mellan olika delar av fyndigheten med avseende på magnetitens kornstorlek och skarnets sammansättning och kornstorlek. Punktanalyser med Laser Ablation Single Collector Inductively Coupled Plasma Mass Spectrometry (LA-SC-ICP-MS) på magnetitkorn i tunnslip från fem olika borrkärnor visar att elementkoncentrationerna i magnetitkornen varierar mellan proverna. Core-to-rim-analyser på magnetitkornen visar att halterna av Fe, Mg, Mn och Al är tämligen homogena genom hela magnetitkornet med undantag av några få avvikande punkter. Fasanalys med XRD indikerar att reduktion har skett i alla försök. Utan prevention visar reduktionsprodukterna från försöken på Fe2O3, Fe3O4 och magnetitmalmkoncentrat klara indikationer av biprodukten NaFeO2. Enligt XRD verkar tillsats av Na2O ha minskat bildningen av Na2O för Fe2O3, Fe3O4 och Tapuli magnetitmalmkoncentrat. Intressant är att ingen NaFeO2 bildades i försöken med FeO. Förklaringen till detta skulle kunna vara avsaknaden av Fe3+ i FeO. De varierande ström-tidkurvorna från försöken tolkas bero på den applicerade spänningen, antalet briketter, brikettsönderdelning och tillsats av Na2O. Elektrolys i smält NaOH kan användas för att reducera järnoxider. Trots detta kanske NaOH inte är lämplig som elektrolyt i denna process, detta på grund av dess påvisade interaktion med Fe2O3 och Fe3O4 som resulterar i bildning av NaFeO2. Na2O kan tillsättas för att förhindra bildning av NaFeO2 men har en kraftigt negativ effekt på strömstyrkan i processen vilket minskar processens effektivitet. En annan preventiv åtgärd som kan testas är att kalibrera processens spänning så att NaFeO2 sönderdelas men inte NaOH. På grund av den konstaterade interaktionstendensen hos NaOH bör andra elektrolyter tas i beaktande för denna process. Angående magnetitmalmskoncentratet från Tapuli behövs fler tester för att dra slutsatser kring hur spårelementen påverkar dess uppförande vid smältelektrolys.