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Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2014-09-05T14:43:24Z No. of bitstreams: 1 Tese de Doutorado Gabriel Luiz dos Santos.pdf: 1820652 bytes, checksum: 813a41cbb9ae01d5c374c54cce45816c (MD5) Approved for entry into archive by Fatima Cleômenis Botelho Maria (botelho@ufba.br) on 2014-09-05T16:01:28Z (GMT) No. of bitstreams: 1 Tese de Doutorado Gabriel Luiz dos Santos.pdf: 1820652 bytes, checksum: 813a41cbb9ae01d5c374c54cce45816c (MD5) Made available in DSpace on 2014-09-05T16:01:28Z (GMT). No. of bitstreams: 1 Tese de Doutorado Gabriel Luiz dos Santos.pdf: 1820652 bytes, checksum: 813a41cbb9ae01d5c374c54cce45816c (MD5) CNPq O presente trabalho realizado em amostras coletadas na Baía de Todos os Santos, Bahia, Brasil, propõe estratégias para determinação multielementar e análise de especiação de vanádio em amostras de moluscos bivalves e sedimentos, empregando ICP OES e ICP-MS. Na primeira parte da tese, foram avaliadas as potencialidades de dois espectrômetros de massa com plasma indutivamente acoplado para determinação de As, Cr, Ni, Se e V em amostras de moluscos bivalves. Para efeito de comparação, três materiais de referência certificados (CRM) foram analisados: NIST 1566b SRM Oyster tissue, NRCC TORT-2 Lobster Hepatopancreas e NIST 2977 SRM Mussel tissue. A condição recomendada, que consistiu na determinação no modo padrão com adição de padrão interno, foi aplicada na determinação dos analitos em amostras de Macoma constricta coletadas em diferentes regiões da BTS. Os resultados apontaram que a maioria dos níveis de As, Cr, Ni, Se e V presentes na espécie Macoma constricta apresentaram valores acima dos níveis estabelecidos pela legislação vigente brasileira que são: 1,0 (As); 0,1 (Cr); 5,0 (Ni); 0,3 (Se) e 0,77 (V) g g-1 (peso úmido), o que representa risco à população e ao ecossistema. Na segunda parte da tese, foram investigadas as condições para a análise de especiação de vanádio em amostras de sedimentos, empregando extração alcalina e determinação por ICP OES. A concentração de V(IV) foi determinada por diferença, considerando a determinação de vanádio total, também realizada por ICP OES, após digestão das amostras com ácido nítrico em forno de micro- ondas com cavidade, usando o procedimento EPA 3051A. O procedimento foi validado através de testes de adição e recuperação e de análise do seguinte material de referência certificado: NIST 2702 (Inorganics in marine sediment). Pelos resultados obtidos pode-se concluir que os compostos contendo V(IV) são mais dominantes nas amostras dos sedimentos analisados. The present work conducted on samples collected in Todos os Santos Bay, Bahia, Brasil, proposes strategies for multielement determination and speciation analysis of vanadium in bivalve molluscs and sediments samples, using ICP OES and ICP-MS. In the first part of the thesis, the potential of two inductively coupled plasma mass spectrometers for determination of As, Cr, Ni, Se and V in bivalve molluscs samples were evaluated. For comparison, three certified reference materials (CRM) were analyzed: NIST 1566b SRM Oyster tissue, NRCC TORT-2 Lobster Hepatopancreas e NIST 2977 SRM Mussel tissue. The recommended condition, which consisted in determining the standard mode with addition of internal standard, was applied in the determination of analytes in samples of Macoma constricta collected in different regions of the BTS. The results showed that most levels of As, Cr, Ni, Se and V present in the species Macoma constricta have values above the levels established by the Brazilian legislation, that are: 1.0 (As); 0.1 (Cr); 5.0 (Ni); 0.3 (Se) and 0.77 (V) g g-1 (wet weight), which represents risk to the population and the ecosystem. In the second part of the thesis, the conditions for speciation analysis of vanadium in soil and sediment samples were investigated, using alkaline extraction and determining by ICP OES. The V (IV) concentration was determined by difference, considering the total vanadium determination, also performed by ICP OES, after the samples digestion with nitric acid in cavity microwave oven, using the procedure EPA 3051A. The procedure was validated through addition and recovery tests and analysis of the following certified reference material: NIST 2702 (Inorganics in marine sediment). From the obtained results it can be concluded that compounds containing V (IV) are majority in the sediment samples analyzed.

Texto completo: acesso restrito. p. 108–114 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2014-05-13T14:46:28Z No. of bitstreams: 1 1-s2.0-S058485471300147X-main.pdf: 539784 bytes, checksum: ce2658bac4bd4f948fea25e7b7e84b64 (MD5) Made available in DSpace on 2014-05-13T14:46:28Z (GMT). No. of bitstreams: 1 1-s2.0-S058485471300147X-main.pdf: 539784 bytes, checksum: ce2658bac4bd4f948fea25e7b7e84b64 (MD5) Previous issue date: 2013 Liquid chromatography–inductively coupled plasma-mass spectrometry (LC–ICP-MS) was used for arsenic speciation analysis in tissues of bivalve mollusks (Anomalocardia brasiliana sp. and Macoma constricta sp.). Microwave and ultrasound radiation, combined with different extraction conditions (solvent, sample amount, time, and temperature), were evaluated for As-species extraction from the mollusks' tissues. Accuracy, extraction efficiency, and the stability of As species were evaluated by analyzing certified reference materials (DORM-2, dogfish muscle; BCR-627, tuna fish tissue; and SRM 1566b, oyster tissue) and analyte recovery tests. The best conditions were found to be microwave-assisted extraction using 200 mg of samples and water at 80 °C for 6 min. The agreement of As-species concentration in samples ranged from 97% to 102%. Arsenobetaine (AsB) was the main species present in bivalve mollusk tissues, while monomethylarsonic acid (MMA) and arsenate (As(V)) were below the limit of quantification (0.001 and 0.003 μg g− 1, respectively). Two unidentified As species also were detected and quantified. The sum of the As-species concentration was in agreement (90 to 104%), with the total As content determined by ICP-MS after sample digestion.

p. 552-557. Submitted by JURANDI DE SOUZA SILVA (jssufba@hotmail.com) on 2011-12-21T10:41:49Z No. of bitstreams: 1 v22n3a20.pdf: 1035144 bytes, checksum: 9a47bc43be5c1daaaae1ec0b37d4b54a (MD5) Made available in DSpace on 2011-12-21T10:41:49Z (GMT). No. of bitstreams: 1 v22n3a20.pdf: 1035144 bytes, checksum: 9a47bc43be5c1daaaae1ec0b37d4b54a (MD5) Previous issue date: 2011-03 Desenvolveu-se um procedimento para determinação de cobre, ferro, chumbo e zinco em amostras de gasolina. O procedimento foi baseado na pré-concentração dos metais empregando uma resina modificada com o ácido 3,4-dihidroxibenzóico (XAD-DHB), seguida da dessorção com solução ácida. Os analitos no eluato foram determinados por espectrometria de absorção atômica em chama multielementar seqüencial (FS-FAAS). As amostras de gasolina foram preparadas como microemulsões misturando-se 80 mL de amostra com 17 mL de propan-1-ol e 3 mL de solução tampão (pH 10). As variáveis físico-químicas que influenciam no processo de extração foram otimizadas. Os LODs obtidos foram 2,2 µg L-1 para Fe, 3,1 µg L-1 para Cu, 2,3 µg L-1 para Pb, e 2,6 µg L-1 para Zn. Os valores de RSDs das concentrações dos analitos nas amostras enriquecidas com 0,05 e 0,1 mg L-1 de cada metal variaram de 5,8 a 9,7%. As recuperações variaram de 82 a 99%. O método foi aplicado na determinação dos analitos em níveis de µg L-1 em amostras de gasolinas coletadas em postos revendedores de Salvador, BA, Brasil. São Paulo

Acesso restrito: Texto completo. p. 12-16. Submitted by JURANDI DE SOUZA SILVA (jssufba@hotmail.com) on 2012-04-13T12:26:35Z No. of bitstreams: 1 __ac.els-cdn.com_S002626...629d352a6b4428ee33e36d4850a89.pdf: 121821 bytes, checksum: c16038ed9e01ca6eef3a18e4e8034f1b (MD5) Made available in DSpace on 2012-04-13T12:26:35Z (GMT). No. of bitstreams: 1 __ac.els-cdn.com_S002626...629d352a6b4428ee33e36d4850a89.pdf: 121821 bytes, checksum: c16038ed9e01ca6eef3a18e4e8034f1b (MD5) Previous issue date: 2010 In the present study, cadmium and lead in the muscle, lung, liver and kidney of dolphins (Sotalia guianensis and Stenella clymene) of the Bahia coast in the northwest of Brazil were determined by graphite furnace atomic absorption spectrometry. Samples were digested using a diluted oxidant mixture (HNO3+H2O2) with a microwave heating programperformed in five steps. The optimized temperatures and chemicalmodifier for the pyrolysis and atomizationwere 700 °C, 1400 °C and Pd plus Mg for Cd, and 900 °C, 1800 °C and NH4H2PO4 for Pb, respectively. Characteristic masses and limits of detections (n=20, 3σ) for Cd and Pb were 1.6 and 9.0 pg and 0.82 ng g−1 and 0.50 ng g−1, respectively. Repeatability ranged from0.87 to 8.22% for Cd and 4.31 to 8.09% for Pb.The found concentrations presented no statistical differences at the 95% confidence level when compared with the ICP OES methods. Addition and recovery tests were also performed and the results ranged between 87 and 112% for both elements. Samples of cetacean Dolphinidae (S. guianensis and S. clymene) were analyzed, and the higher concentrations ranged from 0.09 to 46.2 μg g−1 for Cd and 0.04 to 0.47 μg g−1 for Pb in liver, and from 0.133 to 277 μg g−1 for Cd in the kidney.

Submitted by NUBIA OLIVEIRA (nubia.marilia@ufba.br) on 2018-10-19T17:10:02Z No. of bitstreams: 1 Dissertação corrigida.pdf: 1684958 bytes, checksum: af08e3969b3bf98ca96e309a0a6d0b1b (MD5) Approved for entry into archive by NUBIA OLIVEIRA (nubia.marilia@ufba.br) on 2018-10-19T18:10:46Z (GMT) No. of bitstreams: 1 Dissertação corrigida.pdf: 1684958 bytes, checksum: af08e3969b3bf98ca96e309a0a6d0b1b (MD5) Made available in DSpace on 2018-10-19T18:10:46Z (GMT). No. of bitstreams: 1 Dissertação corrigida.pdf: 1684958 bytes, checksum: af08e3969b3bf98ca96e309a0a6d0b1b (MD5) O presente trabalho propõe estratégias analíticas para determinação de constituintes inorgânicos em medicamentos e suplementos minerais à base de magnésio empregando espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). Inicialmente foi avaliado o efeito de matriz causado pela alta concentração de Mg nos espectros dos elementos As, Ba, Cd, Co, Fe, K, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sn, Sr, V e Zn e nas curvas analíticas de calibração. As linhas selecionadas para cada elemento de acordo com o estudo dos espectros foram, em nm: As (I) 193,696, Ba (I) 455,403, Cd (II) 226,502, Co (II) 238,892, Fe (II) 238,204, K (I) 766,491, Mn (II) 257,610, Mo (I) 202,032, Na (II) 589,592, Ni (II) 216,55, P (I) 213,618, Pb (II) 220,353, Sb (I) 206,834, Se (II) 203,985, Sn (II) 189,927, Sr (II) 407,771, V (II) 311,837 e Zn (I) 213,857. Foram realizados estudos para correção dos efeitos de matriz empregando os seguintes padrões interno (PI): Y (II) 360,074, Sc (II) 361,383 e Be (II) 313,042. A utilização do Be (II) 313,042 como PI mostrou resultados satisfatórios para correção do efeito de matriz para Ba, Cd, Co, Mn, Ni e Pb. Dois métodos foram propostos empregando decomposição em bloco digestor e em forno de micro-ondas com cavidade cujas condições foram selecionadas com base no carbono residual e na acidez residual. A validação foi realizada avaliando-se os limites de detecção (LOD) e de quantificação (LOQ), análise do material certificado FO-01/2012 USP Brachiaria Brizantha cv Marandu enriquecido com Mg, ensaios de adição e recuperação de analitos e precisão. O procedimento empregando forno de micro-ondas com cavidade foi mais eficiente de acordo com os resultados da validação e dos teores de carbono residual quando comparado com a decomposição utilizando bloco digestor. O método proposto foi aplicado nas amostras de suplemento minerais à base de magnésio e leite de magnésia. As faixas de concentração para os elementos determinados em mg g-1 foram: As (0,080-0,099), Ba (0,089-0,097), Ni (0,040-0,046), Pb (0,036-0,042), Cd (0,029-0,033) e Co (0,039-0,045), Sn (0,095-0,246), Se (0,093-0,107), Fe (0,111-4,52), Na (0,132-0,462), K (0,136-2,13), Mn (0,034-0,614), P (0,202-0,928) e Zn (0,092-0,194). Os teores bioacessíveis em % para esses elementos foram Na (79-92), Fe (48-53), K (32-48), P (48-51) e Zn (39-41). De acordo com os resultados encontrados Na foi o elemento que se mostrou mais bioacessível para essas matrizes. As amostras de suplemento minerais à base de magnésio apresentaram teores bioacessíveis para o Mg na faixa de 68-70%. A contribuição deste trabalho está relacionada às estratégias que viabilizaram a avaliação da composição em termos de constituintes inorgânicos em medicamento e suplementos com alto teor de magnésio. This paper proposes analytical strategies for the determination of inorganic constituents in medicines and minerals magnesium supplements using optical emission spectrometry with inductively coupled plasma (ICP OES). Initially it evaluated the matrix effect caused by high concentration of Mg in the spectra of the elements As, Ba, Cd, Co, Fe, K, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sn, Sr, V and Zn and the analytical calibration curves. The lines selected for each element according to the study of the spectra were: As (I) 193.696, Ba (I) 455.403, Cd (II) 226.502, Co (II) 238.892, Fe (II) 238.204, K (I) 766.491, Mn (II) 257.610, Mo (I) 202.032, Na (II) 589.592, Ni (II) 216.55, P (I) 213.618, Pb (II) 220.353, Sb (I) 206.834, Se (II) 203.985, Sn (II) 189.927, Sr (II) 407.771, V (II) 311.837 e Zn (I) 213.857. Studies were performed to correct for matrix effects using the following internal standards (IS): Y (II) 360.074, Sc (II) 361.383 and Be (II) 313.042. The use of Be (II) 313.042 as IS showed satisfactory results for correction of matrix effect for Ba, Cd, Co, Mn, Ni and Pb. Two methods have been proposed employing decomposition block digestor and microwave oven cavity whose conditions were selected based on the residual carbon and residual acidity. The validation was performed evaluating the limits of detection (LOD) and quantification (LOQ), analysis of certified material FO-01/2012 USP Brachiaria Brizantha cv Marandu enriched with Mg, addition and recovery test analytes and accuracy. The procedure employing microwave oven with cavity was more efficient in accordance with the results of the validation and the residual carbon content as compared with the decomposition using digester block. The proposed method was applied to mineral magnesium supplement samples and milk of magnesia. The concentration ranges for the elements determined in mg g-1 were: As (0.080-0.099), Ba (0.089-0.097), Ni (0.040-0.046), Pb (0.036-0.042), Cd (0.029-0.033) e Co ( 0.039-0.045), Sn (0.095-0.246), Se (0.093-0.107), Fe (0.1114.52), Na (0.132-0.462), K (0.136-2.13), Mn (0.034-0.614), P (0.202-0.928) and Zn (0.092-0.194). The bioaccessibility content in % for those elements were Na (79-92), Fe (48-53), K (32-48), P (48-51) e Zn (39-41). According to the results, the Na was the element that was more bioaccessible for these matrices. The mineral magnesium supplement samples were bioaccessibility for Mg levels in the range of 68-70%. The contribution of this work is related to the strategies that enabled the evaluation of the composition in terms of inorganic constituents in medicine and supplements with high magnesium content.