O Estuário de Caravelas, localizado na costa nordeste brasileira (extremo sul da Bahia) é considerado uma zona relativamente não impactada, com importante papel econômico e ecológico, devido a presença de fragmentos de Mata Atlântica, manguezais e sua localização próxima ao Complexo recifal de Abrolhos, o maior e mais importante do Oceano Atlântico Sul. No entanto, especialmente no último século, este estuário tem sido sujeito a impactos naturais e antrópicos que podem ter contribuído com mudanças neste sistema. Portanto, este estudo, baseado em uma abordagem \"multiproxy\", como análise de metais traço, elementos maiores, mineralogia, parâmetros descritivos da composição da matéria orgânica como COT, NT, razão Corg/Ntotal, &#948;13C, teve o objetivo de avaliar registro deposicional natural e antropogênico, do último século em 3 testemunhos datados por 210Pb e 137Cs. As taxas de sedimentação obtidas através do modelo CRS foram de 1,07 &#177; 0,13 cm ano-1 para o testemunho T2 (estuário médio), 0,65 &#177; 0,06 cm ano-1 para o testemunho T5 e 0,85 &#177; 0,09 cm ano-1 (desembocadura). O testemunho localizado no estuário médio (T2) apresentou uma maior influência terrígena com contribuição de plantas C3 para a matéria orgânica (- 26,50 < &#948;13C < -24,39; 21,38 < Corg/Ntotal < 37,67) e teores maiores do argilomineral caulinita, enquanto os testemunhos T5 e T8, localizados próximo a desembocadura do estuário, apresentaram uma maior influência marinha (- 26,48 < &#948;13C < -23,24; 4,18 < Corg/Ntotal < 21,34). Além disso, uma mudança significativa nos \"proxies\" orgânicos e inorgânicos, no início da década de 1960, mostrou a influência da abertura natural de um canal (Boca do Tomba) na hidrodinâmica e na distribuição dos sedimentos. A distribuição de elementos maiores e metais traço não apresentou um enriquecimento significativo e foi associada ao aporte litogênico, indicando o papel do Grupo Barreiras como uma importante fonte de material terrígeno para o estuário de Caravelas. / The Caravelas estuary, located on the Brazilian northeast coast (extreme South of Bahia) is considered a relatively unimpacted zone, with an important economic and ecological role, due to the presence of fragments of Atlantic Forest and mangroves, and its location next to the Abrolhos Bank, the largest and most important reefs of the south Atlantic Ocean. However, especially in the last century, this estuary has been subject to natural and anthropogenic impacts that may have contributed to changes in this system. Therefore, this study, based on a multiproxy approach, such as analysis of trace metals, major elements, mineralogy, parameters describing the composition of organic matter such as TOC, TN, Corg/Ntotal ratio, &#948;13C, had the main goal of evaluating the natural and anthropogenic depositional record, of the last century, in 3 sediment cores dated by 210Pb and 137Cs. The sedimentation rates obtained through CRS model were 1,07 &#177; 0,13 cm y-1 for sediment core T2 (middle estuary), 0,65 &#177; 0,06 cm y-1 for the T5 and 0,85 &#177; 0,09 cm y-1 for T8 (estuary mouth). The sediment core T2 showed a greater terrigenous influence with C3 plant contribution to the organic matter (- 26,50 < &#948;13C < -24,39; 21,38 < Corg/Ntotal < 37,67) and higher contents of kaolinite, meanwhile sediment cores T5 and T8, located at the mouth of the estuary, had a greater marine influence (- 26,48 < &#948;13C < -23,24; 4,18 < Corg/Ntotal < 21,34) and higher contents of calcite and aragonite. Furthermore, a significant change in the organic and inorganic proxies in the early 1960s showed the influence of the natural opening of an inlet (Boca do Tomba) on hydrodynamics and sediment deposition. Finally, the distribution of major and trace elements did not present a significant enrichment and was associated to lithogenic contribution, indicating the role of the Barreiras Group as an important source of terrigenous material to the Caravelas estuary.

Neste trabalho, a decomposição por via úmida em sistema fechado assistida por radiação micro-ondas (MW-AD) e a decomposição por via úmida em sistema fechado assistida por radiação micro-ondas e ultravioleta (MW-UV) foram avaliadas para amostras comerciais de biodiesel para posterior determinação de Ba, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sr, V e Zn por espectrometria de massa com setor eletromagnético com plasma indutivamente acoplado (SF-ICP-MS). A MW-AD empregando ácido diluído foi primeiramente avaliada sendo possível a decomposição de até 700 mg de biodiesel com HNO3 7 mol L-1 e 2 mL de H2O2 30% (m/m). As soluções finais apresentaram teor de carbono residual (RCC) de 8,7% e acidez residual (RA) de 4%. Posteriormente, com o objetivo de obter maior eficiência de decomposição, o método MW-UV foi avaliado para a decomposição de biodiesel. Com o emprego deste método até 950 mg de amostra foram decompostas com HNO3 7 mol L-1 e soluções finais com RCC de 17,4% e RA de 19,3% foram obtidas. As soluções finais, para ambos os métodos, foram adequadas para a determinação de elementos traço por SF-ICP-MS. Possíveis interferências na etapa de determinação dos analitos, causadas pela presença de carbono residual, foram estudadas através do emprego de padrão interno 115In e de ensaios de recuperação de analito para monitorar a formação de espécies poliatômicas no plasma. Os resultados obtidos mostraram a necessidade da utilização de padrão interno, sendo o instrumento operado no modo de baixa resolução para a determinação da maioria dos analitos, com exceção de 52Cr, para o qual o instrumento foi operado no modo de média resolução. A exatidão dos métodos propostos foi avaliada mediante a análise de material de referência certificado, obtendo-se resultados concordantes, com nível de confiança de 95% (teste t-student), com os valores certificados para a maioria dos elementos. Ensaios de adição de analito também foram feitos para a avaliação da exatidão e recuperações de 92 à 109% foram obtidas. Os limites de detecção (LD) obtidos para o método MW-UV foram inferiores aos obtidos para MW-AD, na faixa de 0,08 a 6,9 ng g-1 e 1,0 a 14 ng g-1, respectivamente. / In this work, the microwave-assisted digestion (MW-AD) and microwave-assisted ultraviolet digestion (MW-UV) were evaluated for commercial biodiesel samples for subsequent determination of Ba, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sr, V and Zn by sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). Using the MW-AD method with diluted acid up to 700 mg of biodiesel were digested with 7 mol L-1 HNO3 and 2 mL of 30% (w/w) H2O2. Final solutions presented residual carbon content (RCC) of 8.7% and residual acidity (RA) of 4%. In order to improve the digestion efficiency, the MW-UV method was evaluated for biodiesel digestion. Using MW-UV method up to 950 mg of sample were digested with 7 mol L-1 HNO3 and the final solutions with RCC of 17.4% and RA of 19.3% were obtained. The final solutions obtained for both methods were suitable for the determination of trace elements by SF-ICP-MS. Interferences in the determination step were studied using 115In as internal standard and analyte recovery to monitor the formation of polyatomic species in the plasma. The low resolution mode was used for the determination of almost of the analytes with the exception of 52Cr that was determine using medium resolution mode. Accuracy of the investigated methods were evaluated by analysis of certified reference material and the values obtained were in agreement with 95% confidence level (t-student test) with the certified values for all elements. Analyte recovery was also performed to evaluate the accuracy and recoveries of 92 to 109% were obtained. The limits of detection (LOD) obtained by the MW-UV method were lower than MW-AD method and are in the range of 0.08 to 6.9 ng g -1 and 1.0 to 14 ng g -1, respectively.

Cogumelos são espécies de fungos que têm a capacidade de reter radionuclídeos e elementos estáveis, importantes do ponto de vista tóxicológico e radiológico do meio ambiente. Estudos têm demonstrado que cogumelos podem ser utilizados como bioacumuladores na monitoração e na avaliação de contaminação e qualidade do ecossistema. No presente estudo, foram determinados os radionuclídeos 226Ra, 228Ra, 210Pb e os elementos As, Co, Cr, Cs, Fe, K, La, Mn, Na, Sc, U, Th e Zn em 24 amostras de cogumelos e de solos coletadas na região do Planalto de Poços de Caldas. O Planalto de Poços de Caldas é um exemplo de região de anomalia radioativa, apresentando cerca de 70 delas. No presente estudo, dois grupos de amostragem (do total de sete grupos) foram realizados em locais que apresentam tais anomalias. A determinação dos elementos estáveis foi realizada por Análise por Ativação com Nêutrons. As determinações de 226Ra, 228Ra e 210Pb nas amostras de cogumelos foram realizadas por separação radioquímica e suas atividades foram quantificadas em contador proporcional de fluxo gasoso Alfa e Beta Total. A determinação destes mesmos radionuclídeos nos solos foi realizada por Espectrometria Gama. A determinação dos isótopos de tório nos cogumelos foi realizada por separação radioquímica e quantificada por Espectrometria Alfa. O controle analítico de todas as metodologias utilizadas no presente trabalho foi realizado com o uso de materiais de referência certificados. Foram também analisadas amostras de cogumelos de uma região que não apresenta anomalia radioativa e os resultados comparados com os valores obtidos no Planalto de Poços de Caldas, podendo assim comprovar que cogumelos atuam como indicadores de contaminação radioativa do meio ambiente. As concentrações e atividades mais elevadas foram encontradas nas amostras coletadas nas zonas rurais do Planalto de Poços de Caldas, onde ocorrem as maiores anomalias radioativas na região. Pelos resultados obtidos, pode-se comprovar a eficiência do cogumelo como indicador de contaminação radioativa ambiental, sendo estes apropriados para avaliar os níveis de radioatividade em áreas de Materiais Radioativos de Ocorrência Natural. / Mushrooms are fungi species capable of retaining radionuclides and stable elements that are important to the environment from the toxicological and radiological point of view. Studies have shown that mushrooms can be used as bioaccumulators in monitoring and evaluation of contamination and quality of ecosystems. The present study determined the radionuclides 226Ra, 228Ra and 210Pb and the elements As, Co, Cr, Cs, Fe, K, La, Mn, Na, Sc, U, Th and Zn in 24 samples of mushrooms and soils collected on the Poços de Caldas plateau. The Poços de Caldas plateau has around 70 radioactive anomolies. In the present study, two groups of samples (of a total of seven groups) were taken from areas with radioactive anomalies. The determination of the stable elements was carried out by Neutron Activation Analysis. The determination of 226Ra, 228Ra and 210Pb in mushroom samples was carried out by radiochemical separation and their activities were measured in a Total Alpha and Beta Gas Flow Proportional Counter. These radionuclides were determined in soil by Gamma Spectrometry. The determination of thorium isotopes in mushrooms was carried out also by radiochemical separation and measured by Alpha Spectrometry. The analytical control of the methods utilized in this study was carried out with certified reference materials. Samples of mushrooms of a region that presented no radioactive anomaly were analyzed and compared with values obtained from the Poços Caldas Plateau, in order to identify the behavior of mushrooms as radioactive contamination indicators in their natural environment. Higher concentrations and activities were found in samples collected in the rural area of the Poços de Caldas Plateau, which has the largest radioactive anomalies in the region. The results show that mushrooms are efficient indicators of environmental radioactive contamination and are appropriate to evaluate levels of radioactivity in areas which contain naturally occurring radioactive materials.

Depuis près de 55 ans, TIGF exploite, dans le sud-ouest de la France deux stockages de gaz naturel en aquifère. Le gaz stocké est essentiellement composé de méthane (CH4 à plus de 90 %), mais il contient également d’autres hydrocarbures légers (< C4H10), du diazote (N2), du dioxyde de carbone (CO2), de produits soufrés (H2S, mercaptans) et des composés métalliques présents sous formes de traces ou ultra-traces. L’objectif de la thèse est l’étude du transfert de ces composés vers l’aquifère avec comme cas d’étude : le mercure. Un dispositif expérimental a donc été conçu et développé pour (i) mesurer la solubilité dans l’eau du mercure gazeux présent dans le gaz stocké, ainsi que (ii) pour étudier les phénomènes d’adsorption sur la roche dans les conditions de pression (60 bar) et de température (45°C) du réservoir naturel. Les résultats expérimentaux obtenus en laboratoire ont été utilisés dans un modèle numérique afin de simuler le comportement du réservoir et évaluer notamment les quantités de mercure susceptibles de rester en son sein lors de l’exploitation du stockage. / For nearly 55 years, TIGF operates two gas storages in an aquifer in the southwest of France. The stored gas is mainly composed of methane (CH4 over 90%) but it also contains other light hydrocarbons (<C4H10), nitrogen (N2), carbon dioxide (CO2), sulfur compounds (H2S, mercaptans) and some metallic compounds at traces or ultra traces level. The objective of this thesis was to study the transfer of these compounds to the aquifer with special regard to mercury. An experimental device has been designed and developed to measure (i) the mercury solubility in water and (ii) to study the phenomena of adsorption on the rock in the natural reservoir’s conditions (60 bar and 45°C). The laboratory results were used in a numerical code to simulate the behavior of the reservoir and assess the mercury amount that may remain in it during the storage operation.

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'hydrocarbures. / Timing 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.

Ce travail de recherche porte sur la mise en place d’outils permettant d’évaluer le transfert en éléments trace des sols agricoles vers les plantes. Il a été ciblé sur quatre éléments trace métalliques réglementés dans le sol et/ou la plante à savoir le cadmium, le cuivre, le plomb, le zinc, ainsi qu’un élément trace supplémentaire en voie de réglementation, l’arsenic. Dans un premier temps, un protocole d’échantillonnage a été développé afin de disposer d’un outil de diagnostic pré-récolte. Le cahier des charges a été défini de telle façon que ce protocole soit opérationnel, représentatif de la parcelle, applicable pour différentes parcelles et cultures et autorise une spatialisation de la concentration en éléments trace. Il est de type aléatoire stratifié afin de pouvoir couvrir la totalité de la surface étudiée. Dans un second temps, l’étude s’est portée sur le développement d’une méthode d’analyse des sols par électrochimie afin de disposer d’un outil d’évaluation de la biodisponibilité potentielle des éléments traces et donc du risque de transfert sol - plante. Pour ce faire, les concentrations des éléments sous leurs formes électrolabiles ont été déterminées par voltammétrie de redissolution anodique utilisant des électrodes sérigraphiées élaborées au laboratoire. La méthode a été développée et validée à partir d’une solution de sol de référence minéralisé. Elle a été par la suite appliquée à des solutions de différents sols agricoles obtenues par lixiviation selon un protocole normalisé (NF ISO 18772). / This study concerns the establishment of tools, which allow evaluating the transfer of trace elements from agricultural soils to plants. It focused on four metal trace elements regulated in soil and/or in plants, which are cadmium, copper, lead, zinc, as well as a trace element in the process of regulation, arsenic. First, a sampling protocol was developed in order to dispose of a tool of pre-harvest diagnostic. The specifications were defined such that this protocol is operational, representative of the parcel, applicable to various parcels and crops and authorizes a spatial distribution of the trace element concentration. It is based on random stratified type in order to be able to cover the whole of the considered area. Then, the study focused on the development of a soil analysis method by electrochemistry in order to dispose of a tool for assessing the potential bioavailability of trace elements and therefore the risk of the soil - plant transfer. For that, the electrolabile form concentrations of these elements were determined by anodic stripping voltammetry using screen printed electrodes produced at the laboratory. The method was developed and validated from a solution of a mineralized certified reference soil. It was subsequently applied to solutions of different agricultural soils obtained by leaching according to a normalized protocol (NF ISO 18772).

Parmi les systèmes dédiés à l’analyse directe des solides, la vaporisation électrothermique occupe une place de choix. Elle offre plusieurs avantages. Le temps de préparation des échantillons est considérablement réduit. Il n’y a pas de dilution induite par la minéralisation et les risques de pertes ou de contaminations durant cette étape sont éliminés. Son principe de fonctionnement consiste à transformer, par chauffage, quelques milligrammes d’échantillon en un aérosol, qui est ensuite transporté dans un spectromètre d’émission atomique par plasma à couplage inductif, où la composition élémentaire est mesurée. Une première étude fondamentale a permis de mieux comprendre la dynamique de l’aérosol formé et de définir les meilleures conditions opératoires. L’utilisation de cette technique pour la détermination élémentaire dans les végétaux a présenté cependant des difficultés supplémentaires : difficulté d’étalonnage, effets de matrice et grandes variabilités sur les concentrations mesurées. L’utilisation d’un support de cellulose pour les solutions étalons a permis d’harmoniser les conditions de formation de l’aérosol pour l’échantillon et pour l’étalon, et d’obtenir ainsi des résultats justes. Les effets de matrices ont pu être considérablement réduits par une calcination préalable des échantillons. Le manque de précision des mesures, causée par le manque d’homogénéité des échantillons, a pu être limitée en de réduisant significativement la taille des particules solides. Ces résultats obtenus sur des poudres ont permis d’autres applications comme l’analyse d’échantillons entiers ou la cartographie de la composition chimique d’organes végétaux. / Among the systems dedicated to the direct analysis of the solids, electrothermal vaporization takes up a place of choice. It offers several advantages. The preparation time of the samples is considerably reduced. There is no dilution induced by the digestion and the risks of losses or contaminations during this stage are eliminated. Its functioning consists to convert, by heating, a few milligrams of sample into an aerosol which is then transported in an inductively coupled plasma atomic emission spectrometer, where the elemental composition of the sample is determinate. A first fundamental study allowed to better understand the dynamics of the formed aerosol and to define the best operating conditions. However, the use of this technique to determine the elemental composition of solid plant samples presented additional difficulties: difficulty of calibration, matrix effects and important imprecision on the measured concentrations. The use of a cellulose support for the standard solutions allowed to harmonize the formation of the aerosol between the sample and the standard, and to obtain accurate results. The matrix effects can be considerably reduced by a preliminary dry-ashing of the samples. The variability of measurements, caused by the lack of homogeneity of the samples, was limited by reducing significantly the size of the solid particles. These results, obtained on powders, allowed other applications as the analysis of whole plant samples or the imaging of the chemical composition of plant organs.

Les sols contaminés par les éléments traces potentiellement toxiques (PTTE) ont souvent des conséquences graves pour les écosystèmes terrestres. Plusieurs options de phytoremediaction ont été développées pour remédier les sols contaminés ; cependantl'efficacité et la capacité de ces techniques à réduire les concentrations excessives des éléments traces ou leur (phyto) disponibilité dans les sols contaminés doivent être évaluées Le présent travail s’est intéressé à étudier l'efficacité de deux options de de phytorémédiation, la phytostabilisation et la phytoextraction assistées par des amendements organiques et minéraux, à remédier les fortes concentrations de PTTE dans un sol naturel et dans un technosol contaminés. Les concentrations totales des éléments traces dissous ont été déterminées dans l'eau interstitielle du sol. L'intensité de l'exposition du sol a été évaluée par des capteurs DGT (gradient de diffusion dans les couches minces). Le phytodisponibilité des PTTE a été caractérisée par des tests de germination avec des haricots nains cultivés sur les sols contaminés pour lesquels les concentrations foliaires en éléments traces ont été déterminées. Ensuite un modèle de réseau de neurones artificiels a été appliqué pour comprendre les facteurs les plus pertinents sur la variabilité de la phytodisponibilité des PTTE. Les deux options ont étécapables de réduire les concentrations ou la phytodisponibilité des PTTE en présence des amendements. Les réseaux de neurones artificiels ont été très efficaces pour prédire les résultats manquants et pour déterminer les paramètres de contrôle de la variabilité de la phytodisponibilité des PTTE à partir des paramètres du sol. / Soils contaminated with potentially toxic trace elements (PTTE) often have serious consequences for terrestrial ecosystems. Several phytoremediaction have been developped to reclaim contaminated soils; however the efficiency and capacity of these techniques to reduce excessive concentrations of trace elements or their (phyto) availability in contaminated soils have to be assessed. The present work is focused on studying the effectiveness of two phyoremediation options such as phytostabilisation and phytoextraction assisted by organic and inorganic amendments to remediatethe high concentrations of PTTE in contaminated natural soils and technosoils. Total PTTE concentrations were determined in soil pore water (SPW) sampled by Rhizon soil moisture samplers. The soil exposure intensity was assessed by DGT (diffusive gradient in thin films) probes. The PTTE phytoavailability was characterized by growing dwarf beans on potted soils and analyzing their foliar PTTE concentrations. Then a model of artificial neural network was applied to understand the factors most relevant for the variability on the phytoavailability of trace elements. Both options were found to be able to reduce the concentrations or phytoavailability of PTTE in the presence of amendments. The artificial neural network has been very effective to predict missing results and to determine the control parameters of the variability of the PTTE phytoavailoability from the soil parameters.

Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references. / Pb and Pb isotopes in the ocean have varied on decadal to centennial time scales due to anthropogenic Pb inputs. Thus, tracing the temporal variation of Pb and Pb isotopes in the ocean provides information on the major sources of Pb and the transport of Pb from sources to the ocean surface and into the ocean interior. In this thesis study, first, a method was developed for the analysis of dissolved Pb and other trace elements in seawater using single batch nitrilotriacetate resin extraction and isotope dilution ICP-MS, which was applied in analyzing seawater Pb concentrations in the rest of the study. A -550 year history of the Pb and Pb isotopes in the deep North Atlantic Ocean is reconstructed using a deep-sea coral, showing the infiltration of anthropogenic Pb to deep sea. Comparing the results to the surface North Atlantic Ocean Pb record using a Transit Time Distribution model, the mean transit time of Pb is estimated to be -64 years. This is longer than the transit time estimate assuming simple advection from a source, showing the importance of advective-diffusive mixing in the transport of Pb to the ocean interior. The later part of the thesis investigates Pb in the Indian Ocean, where no useful Pb data have been previously reported. First, using annually-banded surface growing corals, I reconstruct variations of Pb and isotopes in the surface waters of the central and eastern Indian Oceans during the past half-century. Results of the study show the increase of Pb concentrations from the mid-1970s, and major sources of the Pb are discussed, including leaded gasoline and coal burning, based on their emission histories and Pb isotope signatures. Second, Pb concentration and isotope profiles are presented from the northern and western Indian Oceans. Higher Pb concentrations and lower Pb isotope ratios (206Pb/ 207Pb, 208Pb/207Pb) are found in the upper water column (<I 500m) as a result of anthropogenic Pb inputs, and their distributions are largely controlled by the water circulation in the Indian Ocean. / by Jong-Mi Lee. / Ph.D.

O presente estudo propõe uma metodologia para dissolução de tecidos biológicos em sistema de micro-ondas com radiação focalizada e posterior análise elementar por espectrometria de massas com plasma acoplado indutivamente (ICPMS). Foram determinados os elementos arsênio (As), cádmio (Cd), cobre (Cu), chumbo (Pb), níquel (Ni), vanádio (V) e zinco (Zn). A matriz nitro-peroxo-sulfúrica foi comparada com outra sem o ácido sulfúrico e apresentou melhor padrão de recuperação (acima de 90%) na quantificação dos elementos certificados no material de referência TORT-2. As interferências causadas pela presença do ácido sulfúrico na matriz digestora foram contornadas com o uso da célula de reação/colisão com gás hélio (He) e adição deste ácido na composição da curva de quantificação. O ganho analítico proporcionado pelo método de digestão em matriz sulfúrica, em sistema não pressurizado, baseia-se no incremento da temperatura reacional e na degradação completa da matéria orgânica. As digestões tradicionalmente realizadas para quantificação por ICPMS, compostas unicamente de ácido nítrico (HNO3) e peróxido de hidrogênio (H2O2), não apresentam a mesma eficiência na degradação da matéria orgânica em sistemas abertos. Por fim, este método foi aplicado satisfatoriamente em amostras de tecido hepático de peixe Mugil liza (tainha), comprovando sua eficiência em monitorar a bioacumulação, utilizando-se da sensibilidade da técnica multielementar de ICPMS / This study proposes a methodology for dissolution of biological tissues in microwave system with focused radiation and subsequent elemental analysis by mass spectrometry with inductively coupled plasma (ICPMS). The elements arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), vanadium (V) and zinc (Zn) were identified and quantified. The nitro-peroxo-sulfuric acid matrix was compared to another without sulfuric acid and showed better recovery (above 90%) in the quantification of elements in certified reference material TORT-2. The interferences caused by the presence of sulfuric acid in digesting matrix were bypassed by the use of ORS (octapole reaction system) with helium (He) gas and the addition of this acid in the composition of the quantification curve. The gain provided by the analytical method of digestion with sulfuric acid matrix in non-pressurized system, is based on increasing the reaction temperature and the complete degradation of organic matter. Digestions traditionally performed for quantification by ICPMS, composed only with nitric acid (HNO3) and hydrogen peroxide (H2O2), are not as efficient in the degradation of organic matter in open systems. Finally, this method was satisfactorily applied in samples of liver tissue of fish Mugil liza (mullet), proving its effectiveness in monitoring the bioaccumulation, using the sensitivity of multielemental ICPMS technique