La thèse a soulevé deux défis dans l’analyse des métaux dans le riz : (i) un dosage multiélémentaire dans le but de la classification du riz selon l’origine géographique, et (ii) la spéciation du sélénium, élément essentiel dans la nutrition, dans le but de l’identification des cibles moléculaires de son assimilation et stockage. Une méthode d’analyse multiélémentaire par l’ICP MS combinée avec des techniques chimiométriques a été proposée comme outil pour la discrimination des riz selon leurs origines géographiques. Les concentrations des 21 éléments ont été analysées par le diagramme en radar, l’analyse en composantes principales, et l’analyse discriminante linéaire. Le riz thaï (riz jasmin) a pu être discriminé des riz étrangers. De plus, l’analyse discriminante a permis de de différencier les riz produits dans les différentes régions de Thaïlande. L’approche de protéomique assistée par l’ICP MS a permis l’identification d’une douzaine de protéines accumulant préférentiellement le sélénium sous forme de sélénomethionine et de sélénocystéine (en proportion 2:1). / The PhD work is focused on two major analytical chemistry challenges concerning rice characterization: (i) the geographical origin classification of rice based on multi-element fingerprinting and (ii) speciation of selenium with the goal of the identification of molecular target of it assimilation and storage in rice. The methods based on the multi-element fingerprinting by inductively coupled plasma mass spectrometry (ICP-MS) in combination with multivariate statistical techniques were developed and validated as tools for authentication of rice. Twenty-one key variables were assessed by a radar plot technique and multivariate data analysis, including principal component analysis (PCA) and discriminant analysis (DA) enabling classification according to geographical origin. Thai jasmine rice could be clearly differentiated from foreign rice samples. In addition, the DA could be used to classify Thai jasmine rice obtained from different regions in Thailand. In the second part of the project, an analytical ICP-MS-assisted proteomic method was developed for the identification of Se-containing proteins in rice. Selenium was found to be present as both selenomethionine (SeMet) and selenocysteine (SeCys) in a dozen of rice proteins with the Se/S substitution ratio two times higher for SeMet than that for SeCys.

O leite é um alimento completo. Contém micronutrientes, aminoácidos, ácidos graxos em proporções adequadas à nutrição humana. Sua composição pode ser simplificadamente dividida em água, lipídios, glicídios, proteínas e sais minerais. Todavia, a composição do leite não é absoluta. Fatores como raça, sistema de produção, alimentação e clima podem influenciar a qualidade do produto final. Os reflexos da globalização na agropecuária leiteira brasileira resultaram na implantação da Rede Brasileira de Laboratórios Centralizados da Qualidade de Leite (RBQL). A Instrução Normativa nº 51 (IN51), que faz parte do Programa Nacional de Melhoria da Qualidade do Leite (PNMQL), aprovou os regulamentos técnicos de produção, identidade e qualidade do leite tipo A, do leite tipo B, do leite tipo C, do leite pasteurizado e do leite cru refrigerado e o regulamento técnico da coleta de leite cru refrigerado e seu transporte. Cabe à indústria leiteira brasileira, cujo leite é predominantemente oriundo das raças Holandesa, Gir, Girolanda, Jersey, Pardo Suíço e Guzerá, garantir a qualidade do produto comercializado. O desenvolvimento de um sistema de medição confiável é primordial no campo industrial, científico e comercial. Assim sendo, a proposta desse trabalho foi avaliar quimicamente marcas de leite comercial UHT bovino, com diferentes quantidades de gordura e de diferentes unidades federativas do Brasil comprados no comércio da cidade de Piracicaba SP e comparar os valores determinados com os reportados pelos fabricantes na tabela de \"Informações Nutricionais\" nas embalagens, além de investigar a potencialidade da INAA na quantificação química da matriz alimentar em questão. Outro objetivo desse trabalho foi comparar quimicamente o leite oriundo de tanques de resfriamento do estado de Minas Gerais com tanques de resfriamento do estado do Rio Grande do Sul e comparar quimicamente o leite amostrado diretamente de animais de quatro propriedades do estado de São Paulo, fazendo inferências aos limites estabelecidos pela IN51, as legislações vigentes nacional e internacionalmente. Realizou-se também análise exploratória de algumas fontes de nutrientes na alimentação de gado bovino. Com os resultados, observou-se que a preparação das amostras e os procedimentos para a INAA foram empregados com sucesso para a determinação de Br, Ca, Co, Cs, Fe, K, Na, Rb e Zn. Em relação ao comparativo dos valores determinados com os valores declarados pelos fabricantes, Ca apresentou uma tendência dos valores medidos serem menores que os informados, diferentemente do ocorrido com o Na. Dos 16 elementos químicos quantificados pela INAA e ICP-MS, 10 apresentaram diferenças significativas (p < 0,01) entre as propriedades rurais do estado de Minas Gerais e do estado do Rio Grande do Sul. Dos elementos químicos que foram quantificados pela INAA, Br, Cs, K e Rb já foram mencionados em trabalhos desenvolvidos no Laboratório de Radioisótopos como importantes para a discriminação de sistema de produção de diversas culturas. Para o estudo do leite oriundo dos animais, os valores médios determinados para os parâmetros da qualidade, atendiam os limites estabelecidos pela IN51. Para os 16 elementos químicos determinados pela INAA e ICP-MS, Co e Mn foram os únicos em que não se verificaram diferenças significativas (p < 0,05) entre as quatro propriedades pelo teste das comparações múltiplas de Tukey. Pela análise de agrupamento, constatou-se que a raça é primordial para a separação dos grupos, entretanto, o sistema de produção também deve ser levado em consideração. Em relação aos limites máximos de tolerância (LMT) estabelecidos pela legislação brasileira e que possuem valores específicos para leite, verificou-se que As não excedeu os limites máximos estabelecidos, contudo, atenção deve ser dada aos elementos químicos Cr e Se por possuírem valores médios superiores aos LMT. Através dos resultados das frações de massa de volumosos e concentrados, destinados à alimentação de gado bovino, foi possível diferenciar a matriz da fonte de nutriente, bem como a origem / Milk is a complete food. It contains micronutrients, aminoacids, and fatty acids in adequate amounts for human intake. In a simple way, its composition can be divided into water, lipids, lactose, proteins and mineral salts. The composition of milk, however, is not an absolute one. Features such as breed, production system, nourishment and climate can affect the final product quality. The reflex of globalization on the Brazilian dairy husbandry resulted in the creation of the Brazilian Network of Milk Quality Central Laboratories (Rede Brasileira de Laboratórios Centralizados de Qualidade de Leite - RBQL). The Normative Instruction 51 (IN51), a constituent part of the National Milk Quality Improvement Program (PNMQL) has approved the technical regulations of production, identity and quality of type-A milk, type-B milk, type-C milk, pasteurized milk, and refrigerated raw milk as well as the technical regulation for refrigerated raw milk collecting and transportation. The Brazilian dairy industry, with milk mostly deriving from breeds Holandesa, Gir, Girolanda, Jersey, Pardo Suiço and Guzera, is in charge of insuring the quality of the commercialized product. Developing a reliable measuring system is essential in the industrial, scientific and commercial fields. Thus, the aim of this work is to chemically evaluate the brands of commercial UHT bovine milk with different amounts of fat and from different states of Brazil, purchased in the city of Piracicaba, state of São Paulo, and compare the established values with those informed by the manufacturers in the \"Nutritional Facts\" table in the packages labels, in addition to investigating the INAA potentiality in the chemical quantification of the respective feeding matrix. Another goal was to chemically compare the milk deriving from cooling tanks in the state of Minas Gerais and those from cooling tanks in the state of São Paulo, thus inferring on the limits established by the IN51, the national and international legislations in force. Also an exploratory analysis of a few nutrient sources of bovine cattle feeding was observed. The results indicated that the sample preparation and INAA procedures were successfully employed to determine Br, Ca, Co, Cs, Fe, K, Na, Rb and Zn. As to the comparison between the established values and those stated by the manufacturers, the Ca values tended to be lower than the informed ones, unlike what happened to Na. Out of 16 chemical elements quantified by INAA and ICP-MS, 10 showed significant differences (p < 0.01) between the rural properties in the state of Minas Gerais and those in the state of Rio Grande do Sul. Out of the chemical elements quantified by INAA, Br, Cs, K and Rb have already been pointed in works developed at the Laboratory of Radioisotopes as important to discriminate the production system of several crops. In the study of animal-derived milk, the mean values determined for the quality parameters met the limits established by the IN51. For the 16 chemical elements determined by INAA and ICP-MS, Co and Mn were the only ones showing no significant differences (p < 0.05) among all four properties by the Tukey multiple comparison test. Through the cluster analysis the breed was verified to be essential to the separation of groups, however, the production system is also to be taken into account. As to the maximum tolerance limits (MTL) established by the Brazilian legislation and having specific values for milk, the As did not exceed the maximum limits established, yet, attention must be paid to Cr and Se since their mean values are beyond the MTL. The mass fraction results determined in roughages and concentrates for bovine cattle feeding made possible the distinction of the nutrient source matrix and their origin

[pt] Os elementos de maior interesse no biodiesel são os resíduos de catálise do processo produtivo (Na e K), os delimitados por legislação ambiental vigente (S, por exemplo) e os elementos venenosos aos catalisadores automotivos (Pb, V, P e Hg); porém, pesquisas orientadas no sentido de produzir metodologias analíticas para a realização de determinações em biodiesel vêm buscando um mapeamento elementar mais completo do combustível. Técnicas como ICP OES, ICP-MS com célula de reação/colisão, FAAS, GFAAS têm sido usualmente empregadas em determinações diretas ou não, mas ainda existem combinações de preparo de amostra e técnica analítica a ser pesquisadas. O presente trabalho teve como objetivo a avaliação de um sistema de decomposição ácida de amostra de biodiesel, visando à decomposição ácida da maior quantidade possível de matéria orgânica presente na matriz e a consequente determinação em ICP-MS. O processo de decomposição ácida, avaliado pela concentração de carbono residual, determinado em ICP OES, não requer grandes quantidades nem de energia térmica e nem do agente oxidante e ainda permite, após processo de redução da matriz nítrica remanescente, uma determinação direta em ICP-MS utilizando padrões aquosos na confecção das curvas e sem a necessidade de célula de colisão/reação. Foram determinados Ag, Ba, Cu, Mn, Mo, Ni, Ti e Zn em amostras de biodiesel de 4 matérias-primas diferentes e em duas amostras certificadas de biodiesel (NIST) e, tanto os resultados de recuperação, que variaram entre 90 e 110 por cento, quanto o comparativo realizado com as metodologias por ICP OES, validaram os resultados. / [en] Biodiesel appeared in this scenario as an alternative short-term, compatible with the current technologies and without the necessity of major modifications. The elements of greatest interest are the residue of catalyst of the production process (Na, K), those limited by environmental regulations (S) and those that act like poisons for the catalyst system of vehicles (Pb, V, P and Hg), but researches aimed to produce analytical methodologies for determinations in Biodiesel, have sought to achieve a multielement mapping of the fuel (Woods ET AL, 2007). Techniques like ICP OES, ICP-MS with reaction cell, FAAS, GFAAS have been usually used in direct or indirect determinations, but still there are combinations of sample preparation and analytical techniques to be studied. This present work sought to evaluate an analyzing system in ICP-MS after a digestion procedure looking for the minimal quantity of organic matter at the final sample. The preliminary results showed that the digestion process, evaluated by the concentration of residual carbon determined by ICP OES, it can be fast and does not require large amounts of energy and oxidizing agent. And still allow, after reducing the nitric matrix, the use of aqueous standards at the calibration curve. It was monitored Ag, Ba, Cu, Mn, Mo, Ni, Ti and Zn in 4 different sources of raw material for biodiesel, and the method was validated by the analysis of two NIST standards by the comparison with ICP OES results and by the recover results ranged between 90 and 110 per cent.

Les travaux de thèse portent sur le développement de méthodes pour la caractérisation des nanoparticules (NPs) de dioxyde de titane (TiO2) dans les aliments. L’étude a été séparée distinctement en deux axes. Le développement de la méthode AF4-ICP-MS (I) au sein de la Plateforme Nano-Sécurité du CEA de Grenoble et le développement de la méthode Sp-ICP-MS (II) au sein du Laboratoire de la Sécurité Aliments de l’Anses à Maisons-Alfort.Pour le premier axe, les interactions électrostatiques entre les particules et la membrane de l’AF4 ont été étudiées. La charge de surface (potentiel zêta) a été mesuré pour différentes type de particule et membrane en fonction de plusieurs paramètres du solvant tel que le pH, la force ionique ainsi que la présence de tensio-actifs. Suite aux nombreuses analyses effectuées plusieurs conditions de solvant ont été identifiées comme favorable à la répulsion électrostatique entre les particules et la membrane ce qui permettrai de diminuer les pertes de particules au niveau de la membrane. Plusieurs conditions ont donc été testées directement pour l’analyse de NPs de TiO2 en AF4-ICP-MS. Il a ainsi été montré que les conditions favorisant les répulsions électrostatiques permettaient d’améliorer le taux dé récupération des particules au niveau du système AF4. Cependant les analyses ont aussi montré que les NPs de TiO2 n’étaient pas suffisamment dispersées pour pouvoir obtenir une distribution en taille fiable.Le second volet de la thèse, a eu pour but, dans un premier temps, d’optimiser le traitement de données de la méthode Sp-ICP-MS. Plusieurs améliorations ont été réalisées comme le calcul automatique du seuil bruit de fond-particule, le calcul de l'efficacité de transport où encore l'ajout de paramètres de contrôle qualité. Ce traitement de données a ensuite été comparée à un logiciel dédié aux analyses par Sp-ICP-MS et a permis de mettre en avant que la feuille de calcul interne donne des résultats avec une meilleure justesse, tout en fournissant des paramètres supplémentaires.Dans un second temps une optimisation de la méthode Sp-ICP-MS a été réalisée. Plusieurs paramètres ont donc été évalués comme le choix de l’isotope de titane, le temps d’acquisition, le type de solvant pour disperser les particules, ainsi que le mode de prélèvement de l’échantillon et son débit.Enfin, plusieurs aliments ont été analysés après avoir mis en place un protocole d’extraction des NPs. Les résultats obtenus ont permis de déterminer une distribution en taille des NPs de TiO2 présentes dans les échantillons. / The thesis focuses on the development of methods for the titanium dioxide (TiO2) nanoparticles (NPs) characterization in food products. The study was separated distinctly into two axes. The development of the AF4-ICP-MS (I) method within the CEA Nano-Safety Platform in Grenoble and the development of the Sp-ICP-MS (II) method within the Food Safety Laboratory of the Anses in Maisons-Alfort.For the first axis, the electrostatic interactions between the particles and the AF4 membrane were studied. The surface charge (zeta potential) was measured for particles and membranes depending on several solvent parameters such as pH, ionic strength and the presence of surfactants. Following the several analyzes carried out, several solvent conditions have been identified as promoting the electrostatic repulsion between the particles and the membrane, which will make it possible to reduce the losses of particles at the level of the membrane. Several conditions were therefore directly tested for NPs analysis of TiO2 in AF4-ICP-MS. It has thus been shown that the conditions favoring electrostatic repulsions make it possible to improve the efficiency of the particles at the level of the AF4 system. However, the analyzes also showed that the TiO2 NPs were not sufficiently dispersed to obtain a reliable size distribution.The second part of the thesis aimed at first optimizing the data treatment of the Sp-ICP-MS method. Several improvements have been made such as the automatic calculation of the background-particle threshold, the calculation of the transport efficiency or the addition of quality control parameters. This data treatment was then compared to a software dedicated to analyzes by Sp-ICP-MS and made it possible to highlight that the internal spreadsheet gives results with a better accuracy, while providing additional parameters.In a second time an optimization of the Sp-ICP-MS method was carried out. Several parameters were therefore evaluated such as the choice of the titanium isotope, the acquisition time, the type of solvent to disperse the particles, as well as the sample collection mode and its flow rate.Finally, several foods were analyzed after setting up an extraction protocol for NPs. The results obtained made it possible to determine a size distribution of the NPs of TiO2 present in the samples.

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Oxidative stress is imbalance between oxidant and antioxidant levels in living systems. Human cells are protected from reactive oxygen species by endogenous enzymatic antioxidants. Most of these compounds require particular redox metals in their structures as cofactors to allow them to scavenge the free radicals such as Cu, Zn-SOD, Mn-SOD and catalase (Fe). The aim of this study was to quantify these metals in human cells to evaluate their effectiveness as novel biomarkers for measuring oxidative stress. The metals (Zn, Cu, Fe, Mn) were measured in vitro in skeletal muscle cells (C2C12) which were incubated under hypoxia/hyperoxia conditions generated by varying oxygen level from 1%-60% for 24 and 48 hours. Two methods were used to perform the analysis. ICP-MS was applied to liquid samples to quantify Zn, Cu, Fe and Mn in cell populations. And LA-ICP-MS was employed to solid samples to measure their intensity in individual cells. The data acquired from both techniques are positively correlated confirming the reliability of the two approaches. All elements of interest were successfully measured except Mn which was not detected in single cells using LA-ICP-MS due to the limit of detection. Interestingly, the results showed that their concentration increased dramatically in cells grown at 25%-60% O2, the most significant increase was in Cu at 60%O2. None showed any increase at 5%-15% O2 indicating normoxia states. At 1%O2, all elements except Fe showed a significant increase and the most remarkable growth was in Mn. More interestingly, increasing incubation to 48 hours for liquid samples had differing effects on the elements. Zn and Cu concentrations were unaffected by increasing incubation time except at 60%O2 where they showed further growth. In contrast, Mn concentration grew sharply over oxygen levels of 30%-50% with no further effect at 1%, while Fe concentration decreased at 1%O2 and grew steadily over oxygen levels of 5%-60%. It can be concluded that all four elements were significantly affected by stress conditions applied to cells, but at different rates. Importantly, a novel analytical method was introduced in this current study since there have been no previous reported investigations measuring changes in concentration of redox-active elements in human cells subjected to different controlled oxidative stress conditions in vitro.

El número de aplicaciones de la energía laser en el campo científico crece día a día. Estas no solo se han extendido en los campos de química, física y ciencia de materiales, sino también en biología y medicina. Este artículo es una breve introducción a los principios fundamentales del funcionamiento del láser, así como a su aplicación en el campo de la química. / The number of applications of lasers in science is constantly growing, with applications stretching from chemistry, physics and materials science to biology and medicine. This article provides a short overview of the fundamentals of lasers and an introduction to the application of lasers and laser ablation in chemistry.

La richesse en Th et en U de la monazite en fait un excellent géochronomètre pour dater les roches magmatiques et métamorphiques de la croûte terrestre. Peu sensible à la diffusion du Pb dans sa structure cristalline, elle peut enregistrer des évènements géologiques de haute température sans risque de remise à zéro de son géochronomètre. Réservoir principal des actinides et des lanthanides, elle participe à de nombreuses réactions minéralogiques, faisant aussi d’elle un très bon traceur pétrogénétique. Coupler sa chimie à son isotopie permet donc d’interpréter précisément la nature des processus géologiques dont elle enregistre l'âge. L’étude de trois objets géologiques distincts a permis de montrer que la monazite est très sensible aux interactions avec les fluides. Ils vont induire sa dissolution partielle ou totale, suivie de la recristallisation de nouveaux grains. De multiples paramètres vont influencer son comportement face au fluide. Ainsi, à basse température (350°C - 450°C) dans un microgranite, un fluide riche en fluor et carbonates va favoriser la dissolution-précipitation de la monazite, alors qu’un fluide riche en éléments alcalins n’aura aucun effet sur elle. Par contre, à plus haute température (> 600°C) dans des roches métapélitiques, ce même fluide va induire sa dissolution-précipitation. En fonction de la mobilité du Pb, du Th et de l’U, le mécanisme de dissolution-précipitation peut avoir différents impacts sur le géochronomètre : ainsi, l'âge des grains recristallisés peut soit correspondre à l’âge du grain initial, soit dater l’interaction avec le fluide, soit n’avoir aucune signification géologique. Les systèmes isotopiques U-Pb et Th-Pb peuvent également être affectés par l’incorporation de Pb commun dans la monazite lors de sa cristallisation (jusqu’à plusieurs centaines de ppm), ce qui va artificiellement vieillir les âges enregistrés. L'ensemble de ces observations montre que l'âge enregistré par la monazite s'interprète au cas par cas. Dans l’avenir, l’optimisation de l’utilisation de la monazite comme géochronomètre doit passer par (1) une amélioration des techniques d’analyses (augmentation de la résolution spatiale pour résoudre des problèmes géologiques à l’échelle nanométrique, standardisation avec des monazites homogènes) et (2) un couplage de différents types d’analyses (chimie, datation, isotopes de l’oxygène). Ceci devrait permettre d’interpréter aux mieux les âges qu’elle enregistre. / Monazite is regarded as a robust geochronometer in magmatic and metamorphic crustal rocks because it contains high concentrations of Th, and to a lesser extent U. Insensitive to lead diffusion, it possibly records high temperature geological events without resetting. On the other hand, monazite strongly controls the lanthanide and actinide budget in the host-rock and is involved in numerous chemical reactions, which makes it a good petrogenetic tracer as well. Therefore, the coupling of age and chemical data in monazite allows an accurate interpretation of the geological event which is recorded by monazite crystallization. However, monazite is very sensitive to interactions with fluids, which possibly result in its partial or complete dissolution, followed by recrystallization of new grains. The present study has shown that the behavior of monazite during fluid-rock interaction is controlled by several parameters: fluid and rock composition, ligands, pH and temperature. At low temperatures (350°C - 450°C) in a microgranite, monazite is easily disturbed by dissolutionprecipitation in presence of F and CO2 -rich fluid, while an alkali-bearing fluid has no effects on it. By contrast, at higher temperatures (> 600 ° C) in metapelitic rocks, the same alkalibearing fluid induces dissolution-precipitation of monazite. The impact of this process on the geochronometer of depends on Pb, Th and U mobility in the fluid: as a result, the newly formed grained record either the same age as the initial crystal, the age of fluid/rock interaction, or an apparent age without any geological significance. The U-Pb and Th-Pb isotopic systems in monazite can also be affected by the incorporation of common Pb during crystallization (up to several hundred ppm), then increasing artificially the recorded ages. This work has demonstrated that the correct interpretation of the age data in monazite relies on a careful characterization of each geological example and cannot rely simply on commonly accepted paradigms. In the future, optimizing the use of monazite as geochronometer implies to (1) improve the analytical methods (increasing spatial resolution to solve geological problems at the nanometric scale, use of homogeneous monazites as standards) and (2) use a range of geochemical tools (major- and trace elements, U-Th-Pb dating, oxygen isotopes). This would help to better interpret the ages recorded by monazite.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-02-16T15:35:47Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) TESE FINAL NANDIZIA SANTOS.pdf: 2193955 bytes, checksum: ad0f8d4d96ef22fde9239fd8d08f9c60 (MD5) / Made available in DSpace on 2017-02-16T15:35:47Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) TESE FINAL NANDIZIA SANTOS.pdf: 2193955 bytes, checksum: ad0f8d4d96ef22fde9239fd8d08f9c60 (MD5) Previous issue date: 2016-06-27 / CAPES / A elevada concentração de urânio e tório no meio ambiente possibilita maior exposição do homem aos radionuclídeos naturais, necessitando assim, de avaliação devido aos riscos potenciais à saúde humana. No estado da Paraíba, no município de São José de Espinharas, encontra-se uma reserva de urânio, expondo, assim, seus habitantes. Amostras biológicas como cabelo e sangue podem ser utilizadas como bioindicadores para populações expostas, natural ou ocupacionalmente. O presente estudo visou a biomonitoração desses elementos em humanos, através de amostras de cabelo e sangue utilizando o ICP-MS. As concentrações sanguíneas dos doadores apresentaram-se bastante reduzidas, inferiores ao limite de detecção (0,001µg. g-1) para a metodologia proposta. Entretanto, as concentrações de urânio e tório no cabelo para os habitantes de São José de Espinharas variaram de 3,27 a 191,50 µg.g-1 e 0,30 a 9,44 µg.g-1, com médias de 20,73 µg.g-1 e 3,72 µg.g-1, respectivamente. Foram avaliados também, municípios adjacentes, sendo eles: São Mamede, São José do Sabugi e Patos. Os intervalos de concentração e as médias encontradas foram: para urânio de 10,10 a 337,20 µg.g-1 (187,24 µg.g-1 ), 17,87 a 362,38 µg.g-1 (120,90 µg.g-1 ) e 4,08 a 0,30 µg.g-1 ( 7,31 µg.g1 ); e para tório de 0,05 a 21,01 µg.g-1 (5,45 µg.g-1), 0,08 a 6,41 µg.g-1 (2,08 µg.g-1), 0,23 a 7,23 µg.g-1 (4,09 µg.g-1), respectivamente. A média geral do referido estudo foi de 68 µg.g-1 para urânio, e 3,61 µg.g-1 para o tório. Indivíduos cujas concentrações de urânio encontram-se inferiores a 100 µg.g-1 podem ser considerados como não expostos. Demonstrando este fato, os resultados de urânio e tório sérico, indicaram ausência desses elementos na corrente sanguínea. Entretanto, em amostras de cabelo, alguns doadores apresentaram concentrações superiores a este valor, necessitando assim de avaliações adicionais em matrizes diferentes, para testes confirmatórios. Concentrações de tório em cabelo são pouco pesquisadas, não havendo valores para referência. Sugerem-se análises das águas e alimentos para maiores esclarecimentos da exposição e possível intoxicação, visto que, são fontes importantes de contaminação. / The high concentration of uranium and thorium in the environment allows for greater human exposure to natural radionuclides, thus requiring, evaluation of the potential risks to human health. In the state of Paraíba, in São José de Espinharas is a uranium reserves, thereby exposing its inhabitants. Biological samples such as hair and blood can be used as bioindicators of exposed populations, natural or occupationally. The present study aimed biomonitoring of these elements in humans, through hair and blood samples using ICP-MS. Blood concentrations of the donors had to be quite low, below the detection limit (0.001µg. g1 ) for the proposed methodology. However the concentrations of uranium and thorium hair for the inhabitants of São José de Espinharas ranged from 3.27 to 191.50 μg.g-1 and 0.30 to 9.44 μg.g-1, with an average of 20.73 μg.g-1 and 3.72μg.g-1, respectively. Were also evaluated, adjacent municipalities, namely: São Mamede, São José do Sabugi and Patos. The concentration ranges and averages were: uranium to 10.10 to 337.20 μg.g-1 (187.24 μg.g-1), 17.87 to 362.38 μg.g-1 (120.90 μg.g-1) and 4.08 to 0.30 μg.g-1 (7.31 μg.g-1); and thorium from 0.05 to 21.01 μg.g-1 (5.45 μg.g-1), 0.08 to 6.41 μg.g-1 (2.08 μg.g-1), 0.23 to 7.23 μg.g-1 (4.09 μg.g-1), respectively. The overall average of the study was 68 μg.g-1 for uranium, and 3.61 μg.g-1 for thorium. Individuals whose uranium concentrations are below 100 μg.g-1 can be considered unexposed. Demonstrating this fact, the results of uranium and thorium serum, demonstrating the absence of these elements in the bloodstream. However, in hair samples, some donors presented concentrations greater than this value, thus requiring additional assessments in different matrices, for confirmatory tests. Thorium concentrations in hair are little studied, with no values for reference. It is suggested analyzes of water and food for more exposure clarification and possible poisoning, as are important sources of contamination.

No Brasil, ainda não há a realização de pesquisas envolvendo a determinação de elementos químicos em fluidos biológicos e a elaboração de valores de referência para a sua população infantil. O biomonitoramento de elementos químicos apresenta essencial importância na avaliação da saúde humana, no entanto, na análise dos dados dos estudos brasileiros de biomonitoramento, os resultados obtidos são geralmente comparados com valores estipulados para outros países, o que pode gerar uma estimativa equivocada do risco. Sendo assim, o objetivo do presente estudo foi descrever as concentrações médias urinárias de elementos químicos essenciais e não essenciais em crianças brasileiras em fase escolar (6-14 anos), propondo valores de referência para Cd, Co, Li, Mo, Pt e Sb. Para o desenvolvimento do estudo, foram utilizadas amostras de urina obtidas pela \"Pesquisa Nacional para Avaliação do Impacto da Iodação do Sal\" (PNAISAL), sendo tomada uma amostragem de 6.965, escolhidas aleatoriamente, abrangendo 19 unidades da federação e comtemplando as 5 regiões brasileiras. As determinações dos elementos químicos foram realizadas por método de ajuste de matriz, com simples diluição de urina e análise direta por espectrometria de massas com plasma acoplado indutivamente (ICP-MS). Foi realizada dosagem de creatinina nas amostras para ajuste de matriz e correção de possíveis efeitos de diluição. As concentrações médias obtidas para os elementos Cd, Co, Li, Mo, Pt e Sb foram 0,267, 0,769, 7,949, 66,839, 0,022 e 2,389 ?g/g de creatinina, respectivamente. Os dados obtidos foram comparados com resultados de estudos de biomonitoramento para população adulta brasileira e de outros países, evidenciando a necessidade da estipulação de valores próprios para a população infantil brasileira. / There is no research involving the determination of chemical elements in biological fluids and the development of reference values in Brazil for its child population. Human biomonitoring of chemical elements has great importance in human health assessment, however, in analysis of Brazilian biomonitoring studies, the results are usually compared with values established for other countries, which can lead to an erroneous estimate of the risk. Thus, the aim of this study was to determine the concentration of essential and nonessential elements in Brazilian children (6-14 years), proposing reference values for Cd, Co, Li, Mo, Pt and Sb. To develop the study, urine samples obtained by the \"Pesquisa Nacional para Avaliação do Impacto da Iodação do Sal\" (PNAISAL) were used, taking a sample of 6,965 randomly chosen, covering all Brazilian regions. Samples were directly analyzed by inductively coupled plasma mass spectrometry ICP-MS against matrix-matching calibration. Creatinine measurement was done to correct possible effects of sample dilution. The mean concentrations obtained for Cd, Co, Li, Mo, Sb and Pt elements were 0.267, 0.769, 7.949, 66.839, 0.022 and 2.389 ?g/g of creatinine, respectively. The data were compared with results from biomonitoring studies for Brazilian adult and foreign populations, highlighting the need for stipulation of reference values for Brazilian child population.