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"Procedimentos de fracionamento comparados a modelo de atenuação para a avaliação de mobilidade de metais pesados em sedimentos da Baía de Sepetiba, Rio de Janeiro" / EXTRACTION PROCEDURE COMPARED TO ATTENUATION MODEL TO ASSESS HEAVY METALS MOBILITY IN SEDIMENTS FROM SEPETIBA BAY, RIO DE JANEIROAndreza Portella Ribeiro 11 December 2006 (has links)
A baía de Sepetiba, localizada a 60 km na direção Oeste da região metropolitana do Rio de Janeiro, vem sendo submetida, nas últimas décadas, a um considerável desenvolvimento populacional e industrial, contando hoje com aproximadamente 400 indústrias (em sua maioria metalúrgicas) instaladas nas bacias de drenagem da baía, as quais lançam seus resíduos diretamente na baía ou nos corpos d'água da região. Além disso, o Porto de Sepetiba trouxe muitos investimentos industriais para a área. Toda esta expansão industrial e urbana resultou em uma série de impactos ambientais, devido ao lançamento de efluentes domésticos e industriais, os quais são ricos em metais pesados e outras substâncias potencialmente tóxicas. O objetivo deste trabalho foi avaliar a contaminação e mobilidade dos metais Cd, Cu, Ni, Pb e Zn, em sedimentos da baía de Sepetiba. Foram determinados os Sulfetos Voláteis em Ácido (AVS) e os Metais Extraídos Simultaneamente (SEM) em 65 amostras de sedimentos, coletadas de modo a cobrir toda a área da baía. Os resultados obtidos na extração ácida mostraram que os metais Cd, Cu, Pb e Zn apresentaram as mais altas concentrações extraíveis na região NE (principalmente na saídas dos rios Guandu e Canal de São Francisco), enquanto que as mais altas concentrações de Ni foram observadas na porção Oeste da baía. A comparação dos valores dos SEM com os valores guias de qualidade de sedimento (VGQS) canadenses (TEL e PEL) indicou que os metais Cd e Zn apresentaram teores nos quais é freqüente a ocorrência de efeitos negativos à biota (valores acima do PEL); já os metais Cu e Pb e Ni apresentaram concentrações que indicam uma baixa probabilidade de ocorrência de efeitos adversos aos organismos aquáticos de Sepetiba. Por outro lado, a razão S[SEM]/[AVS], ficou abaixo de 1 na porção NE, sugerindo que, apesar das altas concentrações dos metais na região, estes estão retidos no sedimento, na forma de sulfetos. Foram também determinadas as concentrações totais dos metais nos sedimentos, e observou-se que o padrão de distribuição das concentrações totais seguiu o mesmo padrão observado para os SEM, com as mais altas concentrações na porção NE da baía, classificando a área como nivel 2, com relação ao Zn, e como nível 1, com relação aos metais Cd, Cu, Pb e Ni, de acordo com a Resolução CONAMA 344/04. Apresenta-se um modelo geoestatístico, o modelo de atenuação das concentrações, que tem como proposta estimar a mobilidade de um elemento nos sedimentos. O modelo proposto mostrou os mais altos valores de atenuação para Zn, Cd, Cu e Pb na região NE, indicando que a mobilidade destes metais na região é baixa, o que está de acordo com as conclusões obtidas com o modelo S[SEM]/[AVS], indicando boas possibilidades de aplicação do modelo em estudos de contaminação de sistemas estuarinos por metais. / Sepetiba bay, located about 60 km west of the metropolitan region of Rio de Janeiro city, has undergone notable development in the last decades, with the establishment of about 400 industrial plants in its basin, basically metallurgical, which release its industrial waste either straight into the bay or through local rivers. The Sepetiba harbor also brought up a lot of industrial investment in that area. This urban and industrial expansion caused several environmental impacts, mainly due to the presence of heavy metals and other potentially toxic substances present in the effluents discharged into the bay. This work aimed to assess heavy metal (Cd, Cu, Ni, Pb e Zn) contamination and mobility in sediments from Sepetiba bay. The acid-volatile sulfides (AVS) and the concentration of simultaneously extracted metals (S[SEM) were determined in 65 sediment samples from Sepetiba bay, representing the whole area. The results obtained showed that Cd, Cu, Pb and Zn presented higher concentrations in the northeastern area (mainly in the mouth of Guandu and Canal de São Francisco rivers), while the highest concentration of Ni were observed in the western region of the bay. The comparison between SEM concentrations with the Canadian Sediment Quality Guidelines (TEL and PEL) indicated that Cd and Zn presented values which may hazard to aquatic organisms (concentration levels above PEL); the elements Cu, Pb and Ni presented concentration levels below PEL, suggesting low probability of toxicological effects to the aquatic organisms. On the other hand, the ratio S[SEM]/[AVS] was below 1 in the northeastern region, indicating that, in spite of the high concentration of the analyzed metals in this area, they are trapped in the sediment, as sulfides. The total metal concentrations in the sediments were also determined and the same distribution pattern obtained for the SEM were observed, with high concentrations in the northeastern region of the bay, classifying the area as level 2, for Zn, and as level 1, for Cd, Cu, Pb and Ni, according to the CONAMA 344/04 act. A geostatiscal approach is presented, the attenuation of concentrations model, which aims to estimate metal mobility in sediments. The proposed model showed the highest attenuation values for Zn, Cd, Cu and Pb in the northeastern region, indicating that the mobility of these metals is low in this region, suggesting low availability, which is in good agreement with the results obtained by the S[SEM]/[AVS] model. These results indicate good possibilities of applying this model in metal contamination studies in estuarine ecosystems.
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Avaliação de teores de metais e arsênio na Estação Antártica Comandante Ferraz após incêndio de 2012 / Evaluation of metal and Arsenic levels on the Comandante Ferraz Antarctic Station after 2012 fireEdgar Hideki Shinagawa 19 December 2016 (has links)
Em fevereiro de 2012 um incêndio atingiu a Estação Antártica Comandante Ferraz (EACF), consumindo cerca de 70% das instalações, liberando diversos compostos para o meio ambiente. Desde então, processos de remoção de resíduos vêm sendo realizados. Com base no cenário de efeitos ambientais em um ambiente antártico, amostras de solo e sedimento foram coletadas em diferentes períodos pós-acidente a fim de se avaliar os efeitos do incêndio. As amostras foram tratadas através de digestão ácida e as concentrações parciais de metais e As foram quantificadas através de ICP-OES. O Fator de Enriquecimento foi utilizado para avaliação dos impactos causados no solo, enquanto que comparação com os valores estabelecidos pela legislação canadense (TEL e PEL) foi utilizada na avaliação do grau de contaminação do sedimento. Os resultados indicaram a introdução de Pb, Cu e Zn antropogênico em parte das amostras de solo coletadas ao redor da antiga estação antártica, cujos Fatores de Enriquecimento chegaram a, respectivamente, 208,9; 189,7 e 111,6; sendo estes presentes sob a forma de fragmentos metálicos. Também indicaram que os processos de remoção de resíduos podem ter sido tanto responsáveis pela redução nos teores de metais, como por ter reintroduzido estes elementos em outros pontos mobilizando-os durante a movimentação de resíduos. Além disso, não foram encontradas evidências de alterações significativas nos teores de Hg em solo e metais e As em sedimento marinho. / In February 2012, a fire at the Comandante Ferraz Antarctic Station (EACF) destroyed approximately 70% of the Brazilian research station. This event released many substances and residues to the region and, since then, operations for the removal of the fire wastes have been executed. Based on the scenario of environmental effects on an Antarctic environment, soil and sediment samples were collected in several different moments after the accident to study the impacts of the fire. The samples were treated through acid digestion and the partial levels of metals and As were quantified through ICP-OES. Enrichment factor was used to evaluate the impacts caused in soils, and comparisons with Canadian environmental quality guidelines (TEL and PEL) were used to assess the intensity of the sediment contamination. The results indicated the introduction of anthropogenic Cu, Pb and Zn in some of the collected soil samples around the former Antarctic station, with enrichment factors of 189.7, 208.9 and 111.6, respectively, elements those present in metallic fragments. Moreover, the analysis of the generated data showed that the procedures for wastes removal could have been responsible for the decrease in the elements\' content as well as the reintroduction of those elements due to the mobilization of the wastes in some of the sampled sites. Furthermore, there\'s no evidences of significate changes on Hg levels in soil or metal and As levels in marine sediment.
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Nouvelles méthodes de détermination des métaux dans les cendres volantes / New methods of metals determination in fly ash samplesStankova, Alice 08 February 2010 (has links)
Les déchets solides générés par notre société sont nombreux. Les cendres volantes sont des déchets solides produits lors de la combustion de déchets domestiques ou industriels dans des incinérateurs. Les cendres volantes sont également produites par la combustion du charbon dans les centrales à charbon. Les cendres volantes sont des résultats de ces combustions et représentent importante quantité de déchets produits chaque année par notre société. Les possibilités de recyclage de ces déchets sont nombreuses : dans la construction, l'industrie routière. Elles sont également stockées pour une utilisation ultérieure. Les origines différentes des charbons et déchets incinérés conduisent à une minéralogie et une composition élémentaire complexe. En tant que sous-produit le devenir des cendres volantes est important à déterminer, aussi la détermination de la composition élémentaire de ces cendres volantes est-elle indispensable.Les méthodes classiques de préparation des échantillons solides sont la minéralisation acide ou la fusion alcaline. Ces procédures prennent du temps et supposent l’utilisation de réactif, de plus la digestion complète n'est pas toujours assurée. Le risque de contamination par les réactifs employés est important au cours de ces méthodes classiques de préparation. Au cours de la dernière décennie, le développement d’analyse directe d'échantillons solides en utilisant des méthodes d'ablation laser a été important en raison de la nécessité de réduire le temps d'analyse et de réduire aussi la consommation de réactifs. Dans ce travail, deux méthodes basées sur l'ablation par laser seront étudiées pour l'analyse des cendres: Laser Induced Breakdown Spectroscopy (LIBS) et Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). La spectrométrie LIBS sera étudiée pour la détermination quantitative des éléments majeurs dans les échantillons de cendres alors que le couplage ablation laser ICP / MS sera employé pour détermination des éléments traces. L'optimisation de la sensibilité et les stratégies d'étalonnage sont les principaux problèmes traités dans ce travail. La préparation des échantillons et l’optimisation ont été effectuées pour déterminer les éléments tels que Al, As, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Sr, V et Zn par les deux méthodes.Les performances analytiques telles que les limites de détection, justesse ont été obtenus à la suite d'optimisations appropriées des liants et de la sélection de l’étalon interne approprié. En conclusion, l’analyse directe de solides en utilisant les techniques basées sur l’ablation laser développées dans ce travail conduisent à une justesse acceptable pour la détermination des éléments majeurs et traces dans les cendres volantes / Solid waste generated by our society are numerous, fly ashes are produced during the combustion of domestic or industrial waste in incinerators. Fly ashes are also produced through coal combustion in coal fired power plants. Fly ashes are results of these combustions and represent important quantity of waste produced every year by our society. They have variable use – in construction, road industry, or they can be stocked for further use. As they are result of different origin, they have complex mineral and elemental composition. As a by-product or as a recycled product fly ashes fate is important to determine. In this view the determination of the elemental composition of fly ashes is the aim of this work.Conventional methods of sample preparation are acid digestion or alkali fusion. These procedures are time and reagent consuming and complete digestion is not assured. The potential contamination of the reagents employed is important during these classical sample preparation methods. During the past decade, development of direct solid sampling using laser ablation methods was important due to the need of reducing analysis time and also reducing reagent consumption. In this work, two methods based on laser ablation will be studied for fly ash analysis: Laser Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). LIBS will be studied for quantitative determination of major elements in fly ash samples while Laser ablation / ICP MS will be employed for trace element determination.The sensitivity optimization and different calibration strategies are key problems of laser sampling methods. Sample preparation and condition optimisation were performed to determine major, minor and trace elements such as Al, As, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Sr, V and Zn by both methods – LIBS for major elements and LA-ICP-MS for minor and trace elements.Analytical properties such as detection limits, accuracy and analytical working curves were obtained following suitable optimisation of binders and internal standards. Compromise binder and analytical conditions were selected to determine the elements in fly ash samples.In conclusion, direct solid sampling using laser ablation followed by LIBS or for solid introduction into ICP was found to determine major, minor and trace elements in fly ashes, improving pellets mechanical stability, high samples sensitivity and acceptable accuracy and detection limits.
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Approches archéométriques des productions faïencières françaises au XVIIIe siècle : le cas de la manufacture Babut à Bergerac (env. 1740 - 1789) / Archeometrical approaches to french faiences productions of the eighteenth century : the manufacture Babut in Bergerac (circa 1740 - 1789)Emery, Laetitia 26 June 2012 (has links)
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. / Faiences are ceramics defined by a white and opaque glaze, due to the addition of tin oxide decorated or not. This technology appeared during the Abbasid period (VIIIth) and was imported in France around the XIIIth century; they peaked in the XVIIIth century. The previous studies realized on the modern faïences, underline the importance of proceeding to a pluridisciplinarity approach to comprehend this complex material, in the frame of a more global research program on faiences, this work focuses on the production of the South West of France, which have only received limited archaeometrics studies over the last years. The manufacture selected is the fabric of Jean Babut established in the city of Bergerac. The production lasted fifty years until the French Revolution. By analysing all the different results, this work establishes the possibility to proceed to the identification of the production site from technical and material standpoints, to establish a reference group based on the chemical analysis and to design a stylistic reference corpus. A non-destructive methodological approach was developed to evaluate the potential of non-destructive methods to reattribute faiences to a center of production. In addition, this work also reestablishes the production of faiences in the local industrial context and in the french production before the Industrial Revolution.
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Advanced analytical methods for platinum group elements:applications in the research of catalyst materials, recycling and environmental issuesSuoranta, T. (Terhi) 02 August 2016 (has links)
Abstract
Platinum group elements (PGEs) have a high commercial value and variety of applications in different fields of industry. One of the well-known applications is the use of palladium, platinum and rhodium in the catalytic converters of automobiles to reduce the amount of harmful gases emitted to the environment. Advanced analytical methods are needed to deal with issues related to development of new catalyst materials, recycling of PGEs from spent materials and for monitoring PGE emissions to the environment.
In the first part of this study the emphasis was on the catalyst materials. Especially, reliable determination of ruthenium content in catalyst materials required further studies. Consequently, acid digestions in closed vessels using a microwave oven or high pressure asher were compared with a previously reported fusion method. Furthermore, the recovery of PGEs from spent materials is important due to many factors, for example, the high value of these metals, environmental aspects related to their production and possible availability issues in the future. Thus, utilization of microwave-assisted leaching and cloud point extraction (CPE) for the recovery of palladium, platinum, rhodium and ruthenium from catalyst materials was investigated.
The second part of this study concentrated on the PGEs in environmental samples and the analytical challenges related to PGE determinations with inductively coupled plasma mass spectrometry (ICP-MS). Due to the use of PGEs in catalytic converters of automobiles, they are emitted to the roadside environment. The use of Pleurozium schreberi, a terrestrial moss, for active biomonitoring of these emissions was evaluated. Advanced analytical methods were needed to perform interference-free determinations of palladium, platinum and rhodium in these samples. Two alternative approaches for interference elimination were studied. Firstly, the interfering elements were removed using CPE as a chemical separation method. Secondly, interferences were eliminated using ammonia as a reaction gas with the novel ICP-MS/MS (inductively coupled plasma tandem mass spectrometry) technique. / Tiivistelmä
Platinaryhmän alkuaineita hyödynnetään monissa teknisissä sovelluksissa. Yksi tunnetuimmista on autoliikenteen haitallisten päästöjen vähentäminen käyttäen palladiumia, platinaa ja rodiumia autojen pakokaasukatalysaattoreissa. Luotettavia analyysimenetelmiä tarvitaan esimerkiksi kehitettäessä uusia katalyyttimateriaaleja, kierrätettäessä platinaryhmän alkuaineita käytetyistä materiaaleista tai seurattaessa platinaryhmän alkuaineiden määrää ympäristössä.
Tämän tutkimuksen ensimmäinen osa liittyi katalyyttien ruteniumpitoisuuksien määrittämiseen ja platinaryhmän alkuaineiden kierrätykseen katalyyttimateriaaleista. Erityisesti näytteenhajotusvaihe aiheuttaa usein ongelmia ruteniummäärityksissä. Tämän vuoksi tutkimuksessa verrattiin keskenään mikroaaltotekniikalla tai korkeapainetuhkistimella suoritettuja happohajotuksia ja aiemmin raportoidulla sulatemenetelmällä suoritettuja hajotuksia. Mikroaaltoavusteista liuotusta sovellettiin yhdessä samepisteuuton kanssa tutkittaessa katalyyttimateriaalien palladiumin, platinan, rodiumin ja ruteniumin kierrätysmahdollisuuksia. Aihe on ajankohtainen, kun huomioidaan platinaryhmän alkuaineiden korkea hinta, niiden tuotantoon liittyvät ympäristöasiat sekä saatavuuteen liittyvät epävarmuustekijät.
Tutkimuksen toisessa osassa keskityttiin ympäristönäytteisiin ja erityisesti niiden ICP-MS -analytiikan (induktiiviplasmamassaspektrometria) haasteisiin. Autojen katalysaattoreista lähtöisin olevia platinaryhmän alkuaineita päätyy ympäristöön lähinnä teiden varsille. Näitä päästöjä arvioitiin aktiivista biomonitorointia käyttäen. Spektraaliset häiriöt vaikeuttivat kerättyjen sammalnäytteiden (Pleurozium schreberi) palladium-, platina- ja rodiumpitoisuuksien määrityksiä. Tämän vuoksi mittauksissa esiintyvien häiriöiden poistossa hyödynnettiin kahta eri lähestymistapaa. Näistä ensimmäisessä häiritsevät alkuaineet poistettiin kemiallisen erotusmenetelmän, samepisteuuton, avulla. Toisessa tavassa häiriöt poistettiin uudella ICP-MS/MS -tekniikalla (induktiiviplasmatandemmassaspektrometria) käyttäen ammoniakkia reaktiokaasuna.
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A Multiview Extension Of The ICP AlgorithmPooja, A 01 1900 (has links) (PDF)
The Iterative Closest Point (ICP) algorithm has been an extremely popular method for 3D points or surface registration. Given two point sets, it simultaneously solves for correspondences and estimates the motion between these two point sets. However, by only registering two such views at a time, ICP fails to exploit the redundant information available in multiple views that have overlapping regions. In this thesis, a multiview extension of the ICP algorithm is provided that simultaneously averages the redundant information available in the views with overlapping regions. Variants of this method that carry out such simultaneous registration in a causal manner and that utilize the transitivity property of point correspondences are also provided. The improved accuracy in registration of these motion averaged approaches in comparison with the conventional ICP method is established through extensive experiments. In addition, the motion averaged approaches are compared with the existing multiview techniques of Bergevin et. al. and Benjemaa et. al. The results of the methods applied to the Happy Buddha and the Stanford Bunny datasets of 3D Stanford repository and to the Pooh and the Bunny datasets of the Ohio (MSU/WSU) Range Image database are also presented.
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Diodes lasers DFB à couplage par l'indice émettant entre 2 µm et 3,3 µm sur substrat GaSb / Index coupled distributed feedback GaSb based laser diode in the 2µm to 3.3µm rangeGaimard, Quentin 17 December 2014 (has links)
Le développement d'un procédé de détection de gaz atmosphériques à l'état de traces en temps réel, fiable, robuste, sélectif, sensible et portable, est impératif pour répondre à des enjeux sanitaires, écologiques et industriels. La spectroscopie par diodes laser accordables est une des voies envisagées pour pourvoir à ce besoin. Elle nécessite le développement de diodes lasers mono-fréquences émettant en régime continu à température ambiante entre 2 µm et 3.3 µm. Nous reportons ici les modélisations et développements technologiques nécessaires à la fabrication de lasers à contre-réaction répartie – à couplage par l'indice, réseau du 1er et 2nd ordre, sur substrat antimoniure – ainsi que les résultats obtenus. Dans la première partie de ce document, après avoir dressé le contexte de l'étude, nous introduirons la théorie des lasers à contre-réaction répartie et présenterons les modélisations qui ont permis de décrire nos structures. La seconde partie est dédiée aux développements des procédés technologiques qui ont permis de mettre en place deux filières de fabrication de composants – à savoir des lasers DFB à ailettes et lasers DFB à réseau enterré. La troisième partie expose les performances des composants fabriqués et présente les premières mesures d'analyse de gaz effectuées. Ces travaux ont conduit au développement de deux nouvelles filières de fabrication de composants : des diodes lasers mono-fréquences présentant une puissance élevée et une forte sélectivité modale. Les prototypes fabriqués seront utilisés sur des systèmes de spectroscopie. / Development of a reliable, real-time, selective, sensitive and suitable technique for atmospheric trace gas spectroscopy is a critical challenge in science and engineering, for sanitary, ecological and industrial issues. Tunable single-frequency lasers in the 2µm to 3.3µm wavelength range, working in continuous regime at room temperature, can be used in absorption spectroscopy to identify and quantify several atmospheric gases. We report here on the design, the technological development and the performances of 1st and 2nd order index-coupled distributed-feedback (DFB) antimonide-lasers diodes in the 2µm to 3.3µm wavelength range. The first part of this document establishes the context of the thesis, introduces the DFB theory and our modelisation. The second part presents the technological fabrication of the two different components: the side wall corrugated DFB lasers and the buried DFB lasers. The third part shows the performances of the components and the first tests on gas measurement.This work has led to the development of two different kinds of single-frequency laser diodes with high optical power and spectral purity. The fabricated prototypes will soon be used on gas spectroscopy set-up.
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Metodologia para o controle de qualidade e segurança do leite em relação à presença de contaminantes inorgânicosEsteves, Wesley Tinoco 02 December 2014 (has links)
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Previous issue date: 2014-12-02 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente trabalho buscou estabelecer um método para a
determinação de contaminantes inorgânicos em leite cru que fosse
compatível com aplicações em larga escala, como os programas
regulatórios de monitoramento de contaminantes em leite. Para tal,
foi proposta uma abordagem utilizando a técnica de espectrometria
de emissão atômica em plasma (ICP-AES) sem mineralização das
amostras, que foram solubilizadas em solução contendo etanolamina
e ácido cítrico. Estudos foram conduzidos a fim de estabelecer
condições instrumentais em que fosse possível utilizar o preparo
amostral proposto mantendo o compromisso com a sensibilidade,
exatidão e desempenho analítico necessários a fim de se atingir os
limites de detecção requeridos por legislações relacionadas à
segurança alimentar. A proporção ideal de diluição da amostra na
solução de etanolamina e ácido cítrico foi de 1:2 (amostra:solução) e
os valores mais adequados dos parâmetros instrumentais foram
1300W para a radiofrequência do plasma, 0,50L.min-1 para a vazão
do gás auxiliar e 0,60L.min-1 para a vazão do gás de nebulização. Os
limites de quantificação obtidos para Cd, Co, Cr, Cu e Pb foram,
respectivamente, 6,54, 6,57, 14,8, 14,3 e 27,4 μg.mL-1. / This study aimed to establish a method for the determination of
inorganic contaminants in raw milk that was compatible with largescale
applications, such as regulatory programs for the monitoring of
contaminants in milk. For this purpose, an approach using the
technique of atomic emission spectrometry (ICP-AES) with no
mineralization of the samples, which was solubilized in a solution
containing ethanolamine and citric acid, has been proposed. Studies
were conducted in order to establish experimental conditions in
which it was possible to use the proposed sample preparation and
keeping the commitment to sensitivity, accuracy and the analytical
performance required by legislations related to food safety. The ideal
ratio of sample dilution was 1:2 (sample:solution) and the most
suitable values for instrumental parameters were 1300W for the
plasma radiofrequency power, 0.50L.min-1 for the flow of auxiliary
gas and 0.60L.min-1 for the flow of nebulizer gas. The quantification
limits obtained for Cd, Co, Cr, Cu and Pb were, respectively, 6.54,
6.57, 14.8, 14.3 and 27.4 μg.mL-1.
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[en] DETERMINATION OF BIOMOLECULES DERIVED FROM PLATINUM-BASED ONCOLITIC COMPOUNDS IN DIFFERENT CELL LINES / [pt] DETERMINAÇÃO DE BIOMOLÉCULAS DERIVADAS DE COMPOSTOS ONCOLÍTICOS À BASE DE PLATINA EM DIFERENTES LINHAGENS CELULARES29 November 2021 (has links)
[pt] A utilização de drogas à base de platina é o tratamento de primeira linha para diversos tipos de câncer. Pacientes tratados com estas drogas apresentam resultados melhores que os obtidos com outros regimes de quimioterapia para os mesmos tipos de malignidades. As principais limitações para a utilização destes compostos são os efeitos colaterais severos e a resistência dos tumores ao tratamento. A cisplatina foi a primeira droga dessa categoria a ser empregada. Desde o final dos anos 70 até hoje, esta droga vem sendo amplamente utilizada e com sucesso substancial. Acredita-se que o principal mecanismo de ação desta classe de medicamentos seja a ligação de dois sítios ativos da platina com o DNA
das células tumorais, impedindo sua multiplicação e finalmente induzindo a apoptose, o que provoca a redução, e em alguns casos a eliminação, dos tumores. Entretanto, devido à complexidade dos mecanismos envolvidos, uma descrição clara da atuação intracelular destas drogas ainda não foi estabelecida. A combinação de técnicas de separação como eletroforese ou cromatografia líquida de alta performance com técnicas de espectrometria atômica tem se apresentado como uma poderosa alternativa para investigação de fenômenos biológicos que envolvem, de alguma maneira, espécies metálicas. A hifenação destas técnicas permite a separação e detecção em linha de biomoléculas contendo metais, possibilitando a obtenção de informações únicas sobre os processos biológicos. O presente trabalho apresenta o desenvolvimento de métodos analíticos utilizando eletroforese em gel de agarose (GE), cromatografia líquida de alta eficiência (HPLC) e espectrometria de massa com plasma indutivamente acoplado (ICP-MS) para a determinação de biomoléculas contendo platina em materiais biológicos. O
principal objetivo do trabalho é fornecer ferramentas analíticas para o estudo dos mecanismos de ação de drogas à base de platina em humanos. Foram utilizados diversos materiais biológicos, como sangue, urina e culturas de células. A cromatografia líquida em fase reversa foi usada na determinação das drogas intactas e de seus produtos de hidrólise; a cromatografia de exclusão por tamanho foi empregada para a avaliação de proteínas presentes nas amostras enquanto a cromatografia de par iônico para separação de fragmentos de DNA. A detecção de platina nos eluatos por ICP-MS permitiu a obtenção de cromatogramas limpos apresentando claramente as moléculas contendo platina. A evidência da aplicabilidade dos métodos desenvolvidos foi avaliada com a prospecção de biomarcadores de eficiência do tratamento com cisplatina. Diversas linhagens celulares foram expostas a diferentes tratamentos com cisplatina e tiveram seus comportamentos avaliados. A determinação de adutos de DNA contendo platina apresentou-se como uma interessante perspectiva para a obtenção de um biomarcador de resistência ao tratamento com cisplatina. / [en] The use of platinum-based drugs is the first line treatment for many cancers. Patients treated with these drugs present better outcome when compared with other chemotherapy regimens for the same types of malignancies. The major limitations to the use of these drugs are the severe side effects and resistance
tumors present to the treatment. Cisplatin was the first platinum-based drug to be approved for human use. Since the late 1970 s until today, this drug has been widely used with great success. It is believed that the major mechanism of action of these drugs is the binding of two active sites of platinum complexes with the DNA of the tumor cells, preventing their multiplication and finally inducing apoptosis, that leads to a reduction, and in some cases eliminating, tumors. However, due to the complexity of the mechanisms involved, a clear description of the intracellular action of these drugs has not been established. The
combination of separation techniques such as electrophoresis or high performance liquid chromatography with atomic spectrometric techniques has emerged as a powerful alternative for investigation metal-related biological phenomena. The so called hyphenation of these techniques allows the separation and detection of
biomolecules containing metals, making possible to obtain unique information about biological processes. This work presents the development of analytical methodologies using agarose gel electrophoresis (GE), high performance liquid chromatography (HPLC) and inductively coupled plasma with mass spectrometry
(ICP-MS) for the determination of platinum-containing biomolecules in biological materials. The main objective of this work is to provide analytical tools for the study of the mechanisms of action of platinum-based drugs in humans. Various biological materials such as blood, urine and cell cultures were used. Reverse phase liquid chromatography was used for the determination of intact drugs and its hydrolysis products; size exclusion chromatography was used to assess the protein profile in samples while the ion-pair chromatography for separation of DNA fragments. The detection of platinum in the eluates by ICP-MS allowed the obtention of clean chromatograms clearly presenting the platinum-containing molecules. The evidence of the applicability of the developed methods was assessed with the search for biomarkers of efficacy of treatment with cisplatin. Several cell lines were exposed to different treatments of cisplatin and their behavior were evaluated. The determination of DNA adducts containing platinum presented an interesting approach for obtaining a marker of resistance to cisplatin treatment.
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Stanovení platinových kovů ve velkých městských aglomeracích / Determination of platinum group metals in great urban agglomerationsJežek, Stanislav January 2016 (has links)
The aim of this thesis is the actual elaboration literature search concerning the issue of platinum group metals in the environment, determination of platinum and palladium in great urban agglomerations. It includes chemical and physical properties, occurrence and platinum and palladium cycle in the environment. It also contains methods for extraction and determination of platinum and palladium.
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