O objetivo deste estudo foi avaliar parâmetros tais como, moagem, tamanho de partículas, homogeneidade, segregação, dissolução de amostras e amostragem de suspensão, visando o desenvolvimento de método para a determinação de Ir, Pd, Pt e Rh por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) em sílica mesoporosa para uso catalítico. Após a moagem em moinho eletrônico de almofariz e pistilo, a análise do tamanho e distribuição das partículas revelou que 89% das partículas apresentam tamanhos <100 &#181;m e 23% com tamanho <5 &#181;m. Na avaliação de segregação dos analitos na amostra, os resultados obtidos para amostra com moagem grosseira, indicaram que os elementos estão distribuídos de maneira heterogênea entre as frações. Entretanto, a moagem fina aumentou a homogeneidade e esta pode ser uma etapa importante e necessária no sentido de evitar segregação da amostra. A análise por difração e de Raios-X mostrou que não ocorreram reações mecanoquímicas durante a moagem e por fluorescência de Raios-X forneceu resultados discrepantes entre os laboratórios, o pode estar relacionado com a heterogeneidade que induziu erros de amostragem. A avaliação de desempenho do ICP OES foi feita a partir do estabelecimento de parâmetros de mérito como seletividade, repetibilidade, estabilidade, robutez e limite de detecção. Na otimização foram considerados os parâmetros potência, vazão de nebulização e vazão de gás auxiliar. Foi feito um estudo em solução aquosa e em meio da amostra para escolha das linhas de emissão dos elementos Ir, Pd, Pt, Rh e dos candidatos a padrões internos. Apesar dos bons resultados encontrados em solução aquosa, o aumento do sinal de fundo em meio da amostra restringiu a escolha dos comprimentos de onda. Para o estudo da dissolução das amostras foram avaliados quatro procedimentos em forno de micro-ondas com frasco fechado. Os melhores resultados foram obtidos com 150 mg de amostra, 6 mL de água régia e 210 ºC de aquecimento durante 60 min. As determinações por ICP OES usando padrões internos Ru para Pd, Yb para Pt e Dy para Rh foram aquelas que forneceram os resultados mais coerentes com aqueles obtidos por fluorescência de Raios-X. Nos estudos visando à introdução de amostra na forma de suspensão foram avaliados: a massa de amostra para o preparo da suspensão, o efeito da concentração de ácido nítrico e o uso de padrão interno na tentativa de corrigir erros de matriz. 60 mg de amostra com um volume final de 20 mL de ácido nítrico 0,5% (v v-1) foram os escolhidos. Entretanto, a determinação dos elementos via suspensão mostrou resultados muito inferiores aos valores de concentrações esperados. Irídio foi investigado somente para otimização de ICP OES porque a sílica mesoporosa para uso de catalisador automotivo tem não esse elemento em sua composição. / The aim of this study was to evaluate parameters such as grinding, particle size, homogeneity, segregation, sample dissolution and slurry sampling for method development for the determination of Ir, Pd, Pt and Rh in silica mesoporosa for catalyst using inductively coupled plasma optical emission spectrometry (ICP OES). After the grind in an electronic grider with mill and pistil, the analysis of the particle size distribution showed 89% of particles with sizes <100 &#181;m and 23% of particles with sizes <5&#181;m. The separation in different particle size fractions showed that the sample with coarse grind (as sent to the lab) is not homogenous for the elements in comparison with that submitted to grind. X-Ray Diffraction and X-Ray Fluorescence analysis did not showed chemical reactions during the grinding, however a discrepancy between results of different laboratories. The performance of ICP OES was made by using figures of merit such as selectivity, repeatability, stability, robustness and limit of detection. In the optimization of ICP OES power supply, nebulizer flow rate and auxiliary gas flow rate were considered. Studies were conducted in aqueous and in the sample solution to choose emission wavelengths for Ir, Pd, Pt, Rh and internal standard candidates. Despite the good results obtained in aqueous solution, increasing the background signal in sample media restricted the choice of the emission wavelengths. For sample dissolution four procedures using microwave oven with closed-vessel were evaluated. The best results were obtained with 150 mg of the sample, 6 mL of aqua-regia and 210 ºC of heating, during 60 min. Determinations by ICP OES using internal standards Ru for Pd, Yb for Pt, and Dy for Rh were those who provided more consistent results in comparison with those obtained by x-ray fluorescence. For slurry sampling introduction sush parameters were evaluated: the mass of sample to prepare the slurry, the effect of the nitric acid concentration and the use of internal standard to correct matrix effects. 60 mg of the sample with a final volume of 20 mL of nitric acid 0.5% (v v-1) were chosen. However, the determination of Pd, Pt and Rh via suspension showed concentrations below to those expected, as determined by ICP OES in solution. Iridium was investigated only for ICP OES optimization because the silica mesoporosa for automobile catalyst use have not this element in its composition.

A cominuição de amostras geológicas envolve etapas para reduzir seus grãos garantindo sua representatividade, com o auxílio de vários equipamentos de moagem de amostras. São duas as contaminações que podem ser causadas durante o uso desses equipamentos. A primeira é a contaminação primária, pelo contato face a face entre a amostra e os componentes do sistema de moagem, e a segunda é a contaminação cruzada, derivada do material de outras amostras, previamente tratadas, que esteja depositado na superfície dos equipamentos de moagem. São limitadas as informações encontradas na literatura acerca das contaminações primárias, a maioria dos autores presumindo que a mesma seja maior na etapa final dos processos de tratamento. Ainda assim, se faz necessário um estudo sistemático sobre as possibilidades de contaminação primária, durante as diversas etapas de tratamento das amostras. Para esta pesquisa foram utilizadas amostras de quartzo puro, coletado na Fazenda Batatal, em Diamantina, Minas Gerais, com o exame da contaminação primária causada pelo uso dos equipamentos de fragmentação (britador de mandíbulas primário de aço manganês, britador de mandíbulas secundário de carbeto de tungstênio e prensa hidráulica com acessórios de fragmentação em aço) e, a seguir, os de pulverização (moinho de anéis de ágata, carbeto de tungstênio e aço-Cr). O quartzo, um dos materiais mais puros encontrados na natureza, é o que apresenta dureza suficientemente alta para promover intensos processos de interação e contaminação mais extrema. Posteriormente, avaliou-se a possibilidade da contaminação cruzada em quartzo causada pelo tratamento prévio de amostras de basalto (o RS132, da Formação Serra Geral, Rio Grande do Sul) e de granito (o ITU-06.04A, da intrusão Salto, Salto, São Paulo), utilizadas como padrões nos laboratórios do Instituto de Geociências da Universidade de São Paulo, IGc-USP, com composições determinadas por fluorescência de raios X (FRX), no Laboratório de FRX do IGc-USP. As determinações químicas em soluções convenientemente preparadas de amostras de quartzo, utilizadas nas etapas de contaminação primária e cruzada, foram realizadas por espectrometria óptica com plasma indutivo acoplado (ICP-OES) e espectrometria de massa com plasma indutivo acoplado (ICP-MS) no Laboratório de Química e ICP-OES/MS do IGc-USP. Para estudos da contaminação primária foram geradas alíquotas Q1A, Q1B, Q1C, Q2A, Q2B, Q2C, Q3A, Q3B e Q3C (1 identifica tratamento por britador primário de ferro fundido, 2 o britador secundário de CW, 3 a prensa de aço-carbono; e A, B e C identificam os moinhos de anéis na moagem final: ágata, CW e aço-cromo). Nos estudos da contaminação cruzada foram geradas quatro alíquotas, Q4A-Gcc e Q4B-Gcc (quartzo pulverizado, respectivamente, em moinho de anéis de ágata e de CW, após pulverização do granito), e Q4A-Bcc e Q4B-Bcc (quartzo pulverizado nos mesmos moinhos, após tratamento do basalto). A única contaminação registrada foi causada pelos equipamentos durante cominuição primária do quartzo. A ambientação dos moinhos realizada após a moagem de granito ou basalto foi efetuada mediante limpeza rotineira, seguida de moagem com areia quartzosa (a seguir descartada), procedimento efetivo para evitar contaminação cruzada, por remover o material (basáltico ou granítico) aderido às superfícies dos equipamentos. O britador primário de aço manganês colabora com contaminações por Fe e Mn e elementos Cr, Mo, Cu, Sc e Nb, em teores menores. O britador de mandíbulas secundário de CW contaminou com W, provavelmente também com C (determinado por programa Total-Quant), e com algo de Al. A prensa em aço carbono contamina em níveis de 50 ppm de Fe, e teores menores de Cr e Mn. Moinhos pulverizadores de aço temperado contaminaram principalmente com Fe e Cr e, em teores menores, com Mn, W, Ni, Zn, Mo, e V. Cu e Sc aparecem também em níveis extremamente baixos nas amostras tratadas, e podem ser adicionados por estes moinhos. O moinho de anéis de CW contaminou com W (1000 ppm) e Co (70 ppm), aparecendo ainda C com teores apreciáveis; também contamina com Ta e Nb (em torno de 2 e 0,6 ppm, respectivamente). As determinações de vários elementos-traço no quartzo pulverizado em moinho de anéis de ágata ficaram muito próximas, ou abaixo, do limite de detecção das técnicas utilizadas, não se documentando nenhuma contaminação por efeito da utilização deste equipamento. / The grinding of geologic samples is performed to reduce grain size of the constituting minerals and to preserve a representative sample of the original material, with the help of several grinding and milling equipments. The primary and a secondary or crossed contamination are the possible effects that can be produced during these processes. The first is caused by the interaction between the components of the grinding equipments and the sample, the second derives from contamination by other geologic materials previously ground in those equipments. The information found in the previous literature on the subject is relatively limited, most authors assuming that the main contamination may be produced during the final stages of comminution, the one leading to the generation of fine powders. Thus, there is a need to conduct a systematic survey about extent and possibility of primary contaminations. The materials used are samples of pure quartz crystals from the Fazenda Batatal, city of Diamantina, Minas Gerais state, with research initially centered on the examination of primary contamination caused by the fragmentation equipment (manganese steel primary crusher, W carbide secondary crusher, hydraulic press with steel anvil) and then grinding to fine powder (ring grinders equipped with agate, W carbide or chrome-steel rings). Quartz, one of the purest substances found in nature, is a hard mineral that interacts vigorously with the grinding equipment, therefore causing more extreme contamination. A second round was performed testing crossed contamination in quartz caused by previous grinding of basalt (RS 132, Serra Geral Formation, Rio Grande do Sul state) and granite (ITU-06.04A, from the Salto intrusion, city of Salto, São Paulo state), used as standards at the chemistry laboratories of the Instituto de Geociências, Universidade de São Paulo (IGc-USP), with their compositions determined by XRF at Igc-USP. The other chemical determinations, performed on samples of quartz solutions, for checking primary as well as crossed contamination, were performed on ICP-OES and ICPMS equipments, at the Chemistry and ICP-OES/MS Laboratory of Igc-USP. For the testing of primary contamination, the quartz aliquots Q1A, Q1B, Q1C, Q2A, Q2B, Q2C, Q3A, Q3B, and Q3C were prepared (1, 2 and 3 identify, respectively, primary jaw crusher with iron jaws, the secondary crusher with W carbide jaws and the hydraulic press with carbon steel anvil; A, B and C stand for the three used ring grinders, respectively equipped with agate, W carbide and chrome steel rings). Crossed contamination was tested with the aliquots Q4A-Gcc and Q4B-Gcc (quartz samples powdered, respectively, in the agate ring grinder and the CW ring grinder, after grinding of granite), and Q4A-Bcc and Q4B-Bcc (the same procedures as before, now with previous grinding of basalt). The only contamination registered in this study was caused during primary crushing and grinding of the quartz samples. Cleansing of equipment performed after grinding of basalt or granite using conventional cleaning techniques followed by grinding of quartzose sand (later discarded), is a procedure that erases the previous (basaltic or granitic) material from the used equipment; no significant crossed contamination was registered. The primary manganese steel crusher adds principally Fe and Mn to quartz, and elements as Cr, Mo, Cu, Sc and Nb, in lesser amounts. The secondary W carbide jaw crusher contaminates with W, probably also with C (determined with the TotalQuant program), and also with some Al. The carbon steel press contributes with contamination of about 50 ppm Fe, and lesser amounts of Cr and Mn. Powdering mills with tempered steel add mainly Fe and Cr and, to lesser extents, also Mn, W, Ni, Zn, Mo, and V to the quartz; Cu and Sc are present as possible contaminants in very low levels. The W carbide ring mill contaminates quartz with W (around 1000 ppm) and Co (around 70 ppm), adding significant levels of C. This mill contributes also with Ta and Nb additions (2 and 0.6 ppm, respectively). The determination of trace elements in quartz powdered with the agate ring mills does not register significant increases in the analyzed amounts, with levels that remain close to, or below, the respective detection limits, thus possibly precluding any contamination with the use of these mills.

Este trabalho propõe o uso de microfrascos de polipropileno adaptados a um forno de microondas focalizadas como um procedimento alternativo para a preparação de amostras. O pré-tratamento de amostras em microfrascos digestores agrega algumas características importantes como aumento da freqüência analítica, pequena massa de amostra e baixo consumo de reagentes. A eficiência do sistema de digestão foi verificada com o desenvolvimento de metodologia para a determinação de cobre, ferro, manganês, selênio e zinco em cabelo por espectrometria de absorção atômica com atomização por chama ou eletrotérmica em forno de grafite. Os elementos selecionados são essenciais para os seres humanos e são indicadores nutricionais e do bom funcionamento enzimático. O sistema de digestão é constituído de um forno de microondas focalizadas e um tubo de vidro com 30 cm de comprimento e 4 cm de largura, ao qual são colocados quatro ou cinco microfrascos de polipropileno com capacidade para respectivamente 4,0 mL e 2,0 mL. Esses microfrascos foram adaptados a um suporte de Teflon&#174; e fixado a uma haste de vidro, facilitando a introdução e retirada do interior do tubo de vidro. O sistema proposto possibilitou uma drástica redução no tempo de preparo de amostra e melhor eficiência de decomposição (menor teor de carbono residual) em comparação com os procedimentos convencionais. O sistema \"quase fechado\" associado a baixas temperaturas atingidas evitou perdas de elementos por volatilidade, além de apresentar uma ótima homogeneidade de aquecimento entre os microfrascos. A exatidão da metodologia foi verificada através de ensaios de recuperação da análise de um material de referência certificado (IAEA-086) e da análise de amostra com adição e recuperação dos analitos apresentando recuperações de 90 a 103%. / In this work the use of polypropylene vials adapted at focused m1crowaves, as alternative method for sample preparation is proposed. The sample pre-treatment in digestion vials include some desirable characteristics like increase of analytical frequency, low sample mass and low reagents consumption. To check the efficiency of the digestion system the development of a methodology for copper, iron, manganese, selenium and zinc determination using graphite furnace or flame atomic absorption spectrometry was performed. The selected elements are essential for human individual, nutritional indicators and required for enzymatic working. The digestion system is constituted of a focused microwave oven, a glass tube with 30 cm length and 4 cm width, where are setting four or five polypropylene vials with capacity for 4.0 mL and 2.0 mL, respectively, through a Teflon&#174; support assisted by glass haste. The proposed system allowed a drastic reduction of sample preparation time and improved the decomposition efficiency (lower carbon residual content) comparing with conventional methods. The \"almost closed\" system associated with the low temperature avoids elements losses and improve heating homogeneity among the vials. The accuracy of the methodology was ascertained through good recoveries for a certificate reference material (IAEA-086) analysis and good recovery of spiked sample analysis, presenting recovery 90 to 103%.

Le projet vise à développer une nouvelle approche méthodologique dans le but d'améliorer l'utilisation combinée de plusieurs techniques de microscopies infrarouge et X lors de l'analyse de fragments de peintures. Historiquement et ordinairement, les fragments de peintures sont préparés en coupes épaisses polies et les analyses sont réalisées à la surface de ces dernières. Bien que cette préparation d'échantillon facilite sa manipulation ainsi que son orientation lors des analyses, elle limite aussi l'efficacité et la faisabilité de certaines techniques de microscopie. Par conséquent, ce travail propose d'explorer une nouvelle stratégie analytique : la préparation et l'analyse de coupes fines. Ces deux étapes ont été optimisées et validées dans le cadre d'analyses par µFTIR, µXRD, µXRF et µXANES. En parallèle, de nouvelles possibilités analytiques ont été testées dans le cadre de l'analyse des peintures, basées sur la technique XANES plein champ. Les échantillons de peintures se sont révélés être d'excellents candidats pour évaluer les avantages et inconvénients de cette technique pour les matériaux du Patrimoine Culturel en général. / This project aims at developing a new methodological approach, providing a more efficient and synergetic use of FTIR and X-ray microscopies, for the analysis of painting fragments. Usually, painting fragments are prepared as polished sections and analyses are carried out on the cross-section surface. This sample preparation is easy to handle, however ends into critical constraints regarding feasibility and efficiency of micro-analyses. We propose to explore a different strategy: preparation and analysis of thin sections. These preparation procedures were first optimized and validated with µFTIR, µXRF, µXRD and µXANES. Besides, new methodological capabilities based on full-field/µXANES were assessed. Paintings were ideal candidates for estimating pros and cons of this new strategy for CH materials in general.

<p>This thesis concerns the development and validation of high performance liquid chromatography (HPLC) methods aimed for two industrially important areas: (i) analysis of biotechnological synthesis and (ii) determination of adsorption isotherm parameters. There is today a lack of detailed recommendations for analytical procedures in the field of biotechnological production of drugs. Therefore, guidelines were given for analytical development and validation in this field; the production of 9α-hydroxyprogesterone was used as model. In addition, a rapid method using HPLC coupled with diode-array-detection (DAD) and mass spectrometry (MS), was developed for the preliminary identification and quantification of the product. In addition, requirements and recommendations were developed for the selection of the internal standard and for its inclusion in the process liquid. By using this approach the precision and accuracy of the quantitative method were considerably improved. </p><p>Preparative chromatography is a powerful separation method for the purification of pure compounds from more or less complex sample mixtures. One such mixture can be the process liquid from a fermentation, another example can be a racemic mixture of compounds whose enantiomeric constituents must be isolated. Computer-assisted modeling can be used to optimize preparative chromatography. However, competitive adsorption isotherm parameters are required as input data for the computer simulations. In this thesis, a new injection technique, based on a firm theoretical basis, was developed for the peak perturbation (PP) method allowing the determination of binary competitive adsorption isotherm parameters from a broad concentration range. With the new method the determination of adsorption isotherm parameters from a quaternary mixture could be done for the first time. The profiles simulated with these parameters showed excellent agreement with the corresponding experimental profiles, validating the accuracy of the adsorption isotherm parameters derived by the new method.</p>

This thesis concerns the development and validation of high performance liquid chromatography (HPLC) methods aimed for two industrially important areas: (i) analysis of biotechnological synthesis and (ii) determination of adsorption isotherm parameters. There is today a lack of detailed recommendations for analytical procedures in the field of biotechnological production of drugs. Therefore, guidelines were given for analytical development and validation in this field; the production of 9α-hydroxyprogesterone was used as model. In addition, a rapid method using HPLC coupled with diode-array-detection (DAD) and mass spectrometry (MS), was developed for the preliminary identification and quantification of the product. In addition, requirements and recommendations were developed for the selection of the internal standard and for its inclusion in the process liquid. By using this approach the precision and accuracy of the quantitative method were considerably improved. Preparative chromatography is a powerful separation method for the purification of pure compounds from more or less complex sample mixtures. One such mixture can be the process liquid from a fermentation, another example can be a racemic mixture of compounds whose enantiomeric constituents must be isolated. Computer-assisted modeling can be used to optimize preparative chromatography. However, competitive adsorption isotherm parameters are required as input data for the computer simulations. In this thesis, a new injection technique, based on a firm theoretical basis, was developed for the peak perturbation (PP) method allowing the determination of binary competitive adsorption isotherm parameters from a broad concentration range. With the new method the determination of adsorption isotherm parameters from a quaternary mixture could be done for the first time. The profiles simulated with these parameters showed excellent agreement with the corresponding experimental profiles, validating the accuracy of the adsorption isotherm parameters derived by the new method.

Analysis of compounds present in complex matrices is always a challenge, which can be partly overcome by applying various sample preparation techniques prior to detection. Ideally, the extraction techniques should be as selective as possible, to minimize the concentration of interfering substances. In addition, results can be improved by efficient chromatographic separation of the sample components. The elimination of interfering substances is especially important when utilizing mass spectrometry (MS) as a detection technique since they influence the ionization yields. It is also important to optimize ionization methods in order to minimize detection limits. In the work this thesis is based upon, selective solid phase extraction (SPE) materials, a restricted access material (RAM) and graphitized carbon black (GCB) were employed for clean up and/or pre-concentration of analytes in plasma, urine and agricultural drainage water prior to liquid chromatography/mass spectrometry (LC/MS). Two SPE formats, in which GCB was incorporated in µ-traps and disks, were developed for cleaning up small and large volume samples, respectively. In addition, techniques based on use of sub-2 µm C18 particles at elevated temperatures and a linear ion trap (LIT) mass spectrometer were developed to improve the efficiency of LC separation and sensitivity of detection of 6-formylindolo[3,2-b]carbazole (FICZ) metabolites in human urine. It was also found that GCB can serve not only as a SPE sorbent, but also as a valuable surface for surface-assisted laser desorption ionization (SALDI) of small molecules. The dual functionality of GCB was utilized in a combined screening-identification/quantification procedure for fast elimination of negative samples. This may be particularly useful when processing large numbers of samples. SALDI analyses of small molecules was further investigated and improved by employing two kinds of new surfaces: oxidized GCB nanoparticles and silicon nitride.

Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the bysuss revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.

Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the bysuss revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.

Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2014-10-03T17:24:18Z No. of bitstreams: 1 dissertação completa corrigida_Isa _versão cd.pdf: 2410357 bytes, checksum: 77ffa404390e7378887c7388dd9bcce7 (MD5) / Approved for entry into archive by Fatima Cleômenis Botelho Maria (botelho@ufba.br) on 2014-10-06T15:28:52Z (GMT) No. of bitstreams: 1 dissertação completa corrigida_Isa _versão cd.pdf: 2410357 bytes, checksum: 77ffa404390e7378887c7388dd9bcce7 (MD5) / Made available in DSpace on 2014-10-06T15:28:52Z (GMT). No. of bitstreams: 1 dissertação completa corrigida_Isa _versão cd.pdf: 2410357 bytes, checksum: 77ffa404390e7378887c7388dd9bcce7 (MD5) / CNPq, CAPES, FAPESB e PETROBRÁS / O objetivo deste trabalho foi avaliar a distribuição de elementos essenciais e não essenciais em amostras de quatro espécies de moluscos bivalves e de sedimentos coletadas na Baía de todos os Santos (BTS), Bahia, Brasil, após digestão em forno de micro-ondas com cavidade. As amostras foram coletadas em sete localidades, entre setembro de 2010 e maio de 2011. As amostras foram analisadas para As, Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Se, V e Zn por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) e espectrometria de massa com plasma indutivamente acoplado (ICP-MS ). Um procedimento de digestão assistida por micro-ondas otimizado, utilizando ácido nítrico diluído, foi utilizado para digerir as amostras de moluscos bivalves. As amostras de sedimentos foram digeridas em forno de micro-ondas seguindo o procedimento da Agência de Proteção Ambiental, EPA 3051A. A acumulação de metais em tecidos moles dos moluscos bivalves foi dependente da espécie. As amostras da espécie Lucina pectinata apresentaram as maiores concentrações de Cd, Cu e Pb quando comparadas com as espécies Anomalocardia brasiliana, Iphigenia brasiliana e Trachycardium muricatum. Todas as espécies apresentaram concentrações de As e Cr acima do limite máximo tolerável, especificados nas normas brasileiras. A análise exploratória dos dados por HCA e PCA mostrou uma tendência de formação de agrupamentos e caracterizações distintas entre as amostras das espécies Lucina pectinata e Trachycardium muricatum. Os resultados obtidos para as amostras de sedimentos indicaram que para a maioria dos elementos, as maiores concentrações foram encontradas na localidade de Tainheiros, sendo que todos os valores encontrados estão abaixo dos limites estabelecidos pela legislação americana e canadense. Este trabalho contribuiu para o fornecimento de informações inéditas sobre as concentrações de elementos essenciais e não essenciais nas espécies Lucina pectinata, Iphigenia brasiliana e Trachyrcardium muricatum amostradas em diferentes regiões da BTS. Além disso, foram obtidos dados complementares sobre a espécie Anomalocardia brasiliana e sedimentos, contribuindo assim para o monitoramento da região. / The aim of this study was to evaluate the distribution of essential and nonessential elements in samples of four species of bivalve molluscs and sediments collected in the Todos os Santos Bay (TSB), Bahia, Brazil, after digestion in microwave oven cavity. The samples were collected from seven sites in the Todos os Santos Bay, Brazil, between September of 2010 and May of 2011. The samples were analyzed for As, Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Se, V and Zn by inductively coupled plasma-optical emission spectrometry (ICP OES) and inductively coupled plasma mass spectrometry (ICP-MS). An optimized microwave-assisted digestion procedure, using nitric acid diluted, was used to digest the bivalve molluscs samples. The sediment samples were digested in a microwave oven following the procedure of the Environmental Protection Agency, EPA 3051A. Accumulation of metals in bivalve mollusks tissues was specie-dependent. The samples of the species Lucina pectinata showed the highest concentrations of Cd, Cu and Pb. All species showed As and Cr concentrations higher than the maximum tolerable limit, specified in the Brazilian regulation. The exploratory data analysis by HCA and PCA showed a tendency to form two groups between samples of the species Lucina pectinata and Trachycardium muricatum. For the most elements in the results obtained for sediment samples, the highest concentrations were found in Tainheiros, and the values obtained are below the limits set by the Canadian and U.S. law. This work contributed to provide new information about the concentrations of essential and nonessential elements in Lucina pectinata, Iphigenia brasiliana and Trachyrcardium muricatum species sampled in different regions of the TSB. Furthermore, additional data were obtained for Anomalocardia bras