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Obtenção e caracterização de argilas bentonitas modificadas com Brometo de Hexadeciltrimetilamônio para adsorção de pesticidas organoclorados / Obtention and characterization of bentonite clays modified with Hexadecyltrimethylammonium bromide for adsorption of organochlorine pesticidesSANTOS, Matsvilandel Gonçalves dos 03 August 2017 (has links)
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Previous issue date: 2017-08-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Organochlorine (OCs) pesticides are persistent, bioaccumulative substances in the food chain,
with high mobility in the environment. This is of concern, because vry often these compounds
are detected in surface and groundwater, affecting thus quality of water resources and
biodiversity. Because of the serious contamination of aquatic ecosystems by OCs, it is
necessary to develop new and eficiente adsorbent materials for remediation of already
contaminated areas. The objective of this work was to prepare and to characterize organophilic
clays chemically treated with the hexadecyltrimethyl-ammonium bromide salt (HDTMA-Br),
aiming their use as an adsorbent material for the removal of residues of OCs in the environment.
In order to analyze the OCs, was optimized a methodology based on solid phase extraction
followed by gas chromatography with electron capture detector (SPE-GC/ECD). The
characterization of the material was carried out by determination of the cation exchange
capacity (CTC), as well as X-ray diffraction (XRD), infrared spectroscopy (FTIR) and electron
microscopy of scanning (SEM). The adsorptive capacity of the organophilic clay was
determined by kinetic adsorption tests and adsorption isotherms. Chromatographic method,
besides high selectivity, showed adequate linearity (arounding 0.25 to 20.0 µg.L-1), sensitivity
(LODs varying from 0.03 to 0.79 µg.L-1 and LOQs varying from 0.13 to 2.63 µg.L-1) and
precision for trace analysis (CVs varying between 2.16 to 26.69 µg.L-1). The natural clay
presented adequate cation exchange capacity (CTC) for organophilization and the results of the
characterization indicated the intercalation of HDTMA salt cations between the intermediate
layers of the modified clays. The kinetic adsorption assays performed revealed 125% COC as
the best adsorbent, exhibiting affinity for aldrin and 4,4'-DDT pesticides. The experimental data
were better fitted to the pseudo-first-order and pseudo-second order model for the 4,4'-DDT
and aldrin compounds, respectively. The Langmuir isotherm model described better the
adsorption of the 4,4'-DDT compound, whereas the Freundlich model represented better the
adsorption of the aldrin compound, indicating a very favorable adsorption condition. / Pesticidas organoclorados (POCs) são substâncias persistentes, bioacumulativos na cadeia
alimentar, com grande mobilidade no ambiente e frequentemente detectados em águas
superficiais e subterrâneas, causando preocupação com relação à qualidade dos recursos
hídricos e à biodiversidade. Devido à contaminação dos ecossistemas aquáticos por POCs, são
necessários que sejam desenvolvidos novos e eficientes adsorventes para remediação das áreas
já contaminadas. O objetivo deste trabalho foi preparar e caracterizar argilas organofílicas
quimicamente tratadas com o sal brometo de hexadeciltrimetilamônio (HDTMA-Br),
objetivando seu uso como material adsorvente para remoção de resíduos de POCs no ambiente.
Para análise dos POCs, otimizou-se uma metodologia baseada na extração em fase sólida
seguida por cromatografia gasosa com detector por captura de elétrons (SPE-GC/ECD). A
caracterização das argilas foi realizada mediante determinação da capacidade de troca de
cátions (CTC), bem como por análises por difração de raios-x (DRX), espectroscopia no
infravermelho (FTIR) e microscopia eletrônica de varredura (MEV). A capacidade adsortiva
das argilas organofílicas foi determinada por ensaios cinéticos e isotermas de adsorção. O
método cromatográfico, além de elevada seletividade, apresentou adequadas linearidade (0,25
a 20 µg.L-1), sensibilidade (LDs variando de 0,03 a 0,79 µg.L-1 e LQs variando de 0,13 a 2,63
µg.L-1) e precisão para análises de traços (CVs variando entre 2,16 e 26,69 % entre medidas
realizadas no mesmo dia). A argila natural apresentou capacidade de troca catiônica (CTC)
adequada para a organofilização e os resultados da caracterização indicaram a intercalação de
cátions do sal HDTMA entre as camadas intermediarias das argilas modificadas. Os ensaios
cinéticos de adsorção realizados revelaram a argila organofílica 125% CTC como melhor
adsorvente, apresentando afinidade para os pesticidas aldrin e 4,4’-DDT. Os dados
experimentais ajustaram-se melhor ao modelo de pseudo-primeira ordem e pseudo-segunda
ordem para os compostos 4,4’-DDT e aldrin, respectivamente. O modelo de isoterma de
Langmuir descreveu melhor a adsorção do composto 4,4’-DDT, enquanto que o modelo de
Freundlich representou melhor a adsorção do composto aldrin, indicando condição de adsorção
bastante favorável.
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Air-Surface Exchange of Persistent Organic Pollutants in North AmericaWong, Fiona 18 January 2012 (has links)
This thesis examines the air-soil and air-water gas exchange of persistent organic pollutants (POPs) with emphasis on organochlorine pesticides (OCPs). The current status of net exchange, factors which influence the exchange process, and different approaches used to estimate the surface exchange were explored. The net exchange of chemicals was evaluated using the fugacity approach, with the aid of chemical tracers (congener profiles of complex mixtures and enantiomer proportions of chiral chemicals) to infer current use vs. legacy sources to the atmosphere. DDT in southern Mexico was undergoing net deposition from air to soil. Occurrence of fresher DDT residues in the south was indicated by a higher proportion of p,p’-DDT relative to p,p’-DDE and racemic o,p’-DDT in air and soils. Congener profiles of toxaphene suggested soil emissions as the source to air. The influence of chemical aging on soil-air exchange and bioaccessibility was studied in a high organic soil. The use of nonexhaustive extraction with hydroxypropyl-beta-cyclodextrin (HPCD) to predict bioaccessibility was optimized for OCPs and polychlorinated biphenyls (PCBs). Reduced volatility of spiked chemicals correlated with reduced HPCD extractability for soil that had been aged under indoor and outdoor conditions for 730 d and infers volatility could be used as a surrogate for bioaccessibility. Measured soil-air partition coefficients (Ksa) were lower than those predicted from the Karickhoff relationship, which considers octanol as a surrogate for soil organic matter. The role of soil moisture, organic carbon, temperature, depth of soil surface horizon and dissolved organic carbon in the fate of organic contaminants in soil were assessed using chemical partitioning space maps. These maps allow instant visual prediction of the phase distribution and transport process of a chemical among the three major phases in soil; i.e., air, water and solid. Net volatilization of alpha-hexachlorocyclohexane from water to air was found in the southern Beaufort Sea using fugacity calculations and flux measurements. The influence of ice cover on volatilization was indicated by a winter-summer shift from racemic to nonracemic alpha-HCH in boundary layer air.
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Air-Surface Exchange of Persistent Organic Pollutants in North AmericaWong, Fiona 18 January 2012 (has links)
This thesis examines the air-soil and air-water gas exchange of persistent organic pollutants (POPs) with emphasis on organochlorine pesticides (OCPs). The current status of net exchange, factors which influence the exchange process, and different approaches used to estimate the surface exchange were explored. The net exchange of chemicals was evaluated using the fugacity approach, with the aid of chemical tracers (congener profiles of complex mixtures and enantiomer proportions of chiral chemicals) to infer current use vs. legacy sources to the atmosphere. DDT in southern Mexico was undergoing net deposition from air to soil. Occurrence of fresher DDT residues in the south was indicated by a higher proportion of p,p’-DDT relative to p,p’-DDE and racemic o,p’-DDT in air and soils. Congener profiles of toxaphene suggested soil emissions as the source to air. The influence of chemical aging on soil-air exchange and bioaccessibility was studied in a high organic soil. The use of nonexhaustive extraction with hydroxypropyl-beta-cyclodextrin (HPCD) to predict bioaccessibility was optimized for OCPs and polychlorinated biphenyls (PCBs). Reduced volatility of spiked chemicals correlated with reduced HPCD extractability for soil that had been aged under indoor and outdoor conditions for 730 d and infers volatility could be used as a surrogate for bioaccessibility. Measured soil-air partition coefficients (Ksa) were lower than those predicted from the Karickhoff relationship, which considers octanol as a surrogate for soil organic matter. The role of soil moisture, organic carbon, temperature, depth of soil surface horizon and dissolved organic carbon in the fate of organic contaminants in soil were assessed using chemical partitioning space maps. These maps allow instant visual prediction of the phase distribution and transport process of a chemical among the three major phases in soil; i.e., air, water and solid. Net volatilization of alpha-hexachlorocyclohexane from water to air was found in the southern Beaufort Sea using fugacity calculations and flux measurements. The influence of ice cover on volatilization was indicated by a winter-summer shift from racemic to nonracemic alpha-HCH in boundary layer air.
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Ocorrência de PCBs, PBDEs e pesticidas organiclorados em Prionace glauca da costa sul brasileira / Ocurrence of PCBs, PBDEs and organochlorine pesticides in Prionace glauca from Braziliam south coastMauro Juliano Cascaes 29 June 2009 (has links)
Existem muitos estudos sobre a ocorrência de poluentes orgânicos persistentes (POPs) no ambiente marinho utilizando bioindicadores como os tubarões. Entretanto, no Brasil, ainda há carência de dados de POPs nesses organismos. O objetivo desta pesquisa foi investigar a ocorrência e o comportamento dos PCBs, pesticidas organoclorados e PBDEs no ambiente marinho, a partir da utilização dos tubarões como indicadores. Musculatura e fígado de vinte tubarões-azul (Prionace glauca) foram coletados em agostosetembro de 2008. Os PCBs foram os poluentes predominantes, presentes em 80% das amostras, com concentrações variando de <n.d. a 427,28 ng.g-1 de peso úmido. Os diclorodifeniletanos apresentaram concentrações variando de 0,43 a 202,42 ng.g-1 de peso úmido, no qual o 4,4´-DDE foi o composto mais significativo, com 77,6% de contribuição para os DDTs totais. As concentrações no fígado foram 1-2 ordens de grandeza mais elevadas, em relação às de musculatura. Houve um padrão de distribuição dos poluentes com níveis equivalentes entre indivíduos imaturos. Os machos maduros apresentaram concentrações de POPs sensivelmente maiores que as fêmeas maduras, indicando a transferência dos POPs para os filhotes. Os resultados demonstraram a ampla distribuição desses poluentes no ambiente marinho. / There are many studies about the occurrence of persistent organic pollutants (POPs) in the marine environment using sharks as bioindicators. However, there is still a lack of data of POPs in those organisms in Brazil. The goal of this research was to investigate the occurrence and behavior of PCBs, organochlorine pesticides and PBDEs in the marine environment, using sharks as indicators. Muscle and liver of twenty blue-sharks (Prionace glauca) were collected in august-september 2008. The PCBs were the predominant pollutants and being present in 80% of samples, with concentrations ranging from <n.d. to 427.28 ng.g-1 wet weight. The dichlorodiphenylethanes present concentrations ranging from 0.43 to 202.42 ng.g-1 wet weight, where the 4,4´-DDE was the most significative compound, with contributions of 77,6% of the total DDTs. The concentrations in the liver were 1-2 orders of magnitude higher than in the muscle. There was a distribution pattern of the pollutants, with equivalent levels among the immature specimens. The concentration of POP was significantly higher in the mature males and relatively lower in the mature female, showing the maternal transference of POPs to the pups. The results have demonstrated a wide distribution of these pollutants in the marine environment.
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Ocorrência de Pesticidas Organoclorados e Bifenilos Policlorados em tartarugas marinhas Chelonia mydas / Occurrence of organochlorine pesticides and polychlorinated biphenyls in sea turtles Chelonia mydasJosilene da Silva 25 June 2009 (has links)
Os compostos organoclorados (OCs), como pesticidas e bifenilos policlorados (PCBs), são persistentes, tóxicos e amplamente distribuídos através do transporte atmosférico e correntes oceânicas. Poucos são os estudos realizados de OCs em tartarugas, sendo que nenhum foi realizado na costa brasileira. A Chelonia mydas é a maior tartaruga marinha de carapaça dura, que se distribue por todos os oceanos, nas zonas de águas tropicais e subtropicais. O presente trabalho visa verificar a ocorrência de organoclorados na espécie C. mydas, bem como sua possível relação com algum tipo de alteração morfológica ou fisiológica. Foram coletadas amostras de gordura, fígado, rim e músculo em 27 espécimes juvenis do litoral de Ubatuba, São Paulo. Os organoclorados foram extraídos com solventes orgânicos e o extrato foi purificado com ácido concentrado. A identificação e quantificação dos PCBs e pesticidas foram realizadas em cromatógrafo a gás com espectrômetro de massas e com detector de captura de elétrons, respectivamente. Os pesticidas organoclorados não foram detectados em nenhuma amostra. As concentrações de PCBs totais em peso úmido foram de: <1,6 48,9 ng.g-1 em gordura, <1,6 17,4 ng.g-1 no fígado e <1,6 9,2 ng.g-1 no rim. Os baixos níveis encontrados estão relacionados principalmente a sua dieta alimentar, uma vez que a C. mydas é basicamente herbívora, e ao local de coleta, que é uma região não industrializada. / Organochlorine compounds, such as pesticides and polychlorinated biphenyls (PCBs), are persistent, toxics and widely distributed due to the atmospheric transport and oceanic currents. Few studies have reported the occurrence of these compounds in turtles, but none from the Brazilian Coast. Chelonia mydas is the biggest marine turtle with hard carapace that extends throughout tropical and subtropical seas around the world. The present study aims to assess the concentrations of organochlorines in the C. mydas as well as any relationship with morphological or physiological variations. Fat, liver and kidney samples were collected from 27 juvenile specimens found dead in Ubatuba Coast, São Paulo State. Organochlorine were extracted with organic solvents and the extracts were purified with concentrated acid. PCBs and pesticides were identified and quantified using a gas chromatograph with mass spectrometer and with electron capture detector, respectively. Pesticides were not detected in any sample analyzed. PCBs concentrations in wet weight were: <1.6 48.9 ng.g-1 in fat, <1.6 17.4 ng.g-1 in liver and <1.6 9.2 ng.g-1 in kidney. The low levels detected are related, especially, to the feeding habits of the species since C. mydas is mainly herbivore, and to a non industrialized sampling area.
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Organohalogen contaminants in wildlife from the Yangtze River Delta : Development of methods and assessments of legacy and emerging persistent organic pollutantsYin, Ge January 2016 (has links)
Rapid economic development has occurred during the past few decades in China with the Yangtze River Delta (YRD) area as one of the most progressive areas. The urbanization, industrialization, agricultural and aquaculture activities result in extensive production and application of chemicals. Organohalogen contaminants (OHCs) have been widely used as i.e. pesticides, flame retardants and plasticizers. They are persistent, bioaccumulative and pose a potential threat to ecosystem and human health. However, limited research has been conducted in the YRD with respect to chemicals environmental exposure. The main objective of this thesis is to investigate the contamination level, distribution pattern and sources of OHCs in the YRD. Wildlife from different habitats are used to indicate the environmental pollution situation, and evaluate selected matrices for use in long term biomonitoring to determine the environmental stress the contamination may cause. In addition, a method is developed for dicofol analysis. Moreover, a specific effort is made to introduce statistic power analysis to assist in optimal sampling design. The thesis results show extensive contamination of OHCs in wildlife in the YRD. The occurrences of high concentrations of chlorinated paraffins (CPs) are reported in wildlife, in particular in terrestrial species, (i.e. short-tailed mamushi snake and peregrine falcon). Impurities and byproducts of pentachlorophenol products, i.e. polychlorinated diphenyl ethers (PCDEs) and hydroxylated polychlorinated diphenyl ethers (OH-PCDEs) are identified and reported for the first time in eggs from black-crowned night heron and whiskered tern. High concentrations of octachlorodibenzo-p-dioxin (OCDD) are determined in these samples. The toxic equivalents (TEQs) of polychlorinated dibenzo-p-dioxin (PCDDs) and polychlorinated dibenzofurans (PCDFs) are at mean levels of 300 and 520 pg TEQ g-1lw (WHO2005 TEQ) in eggs from the two bird species, respectively. This is two orders of magnitude higher than European Union (EU) regulation limit in chicken eggs. Also, a novel pattern of polychlorinated biphenyls (PCBs) with octa- to decaCBs, contributing to as much as 20% of total PCBs therein, are reported in birds. The legacy POPs shows a common characteristic with relatively high level of organochlorine pesticides (i.e. DDT, hexacyclohexanes (HCHs) and Mirex), indicating historic applications. In contrast, rather low concentrations are shown of industrial chemicals such as PCBs and polybrominated diphenyl ethers (PBDEs). A refined and improved analytical method is developed to separate dicofol from its major decomposition compound, 4,4’-dichlorobenzophenone. Hence dicofol is possible to assess as such. Statistic power analysis demonstrates that sampling of sedentary species should be consistently spread over a larger area to monitor temporal trends of contaminants in a robust manner. The results presented in this thesis show high CPs and OCDD concentrations in wildlife. The levels and patterns of OHCs in YRD differ from other well studied areas of the world. This is likely due to the extensive production and use of chemicals in the YRD. The results strongly signal the need of research biomonitoring programs that meet the current situation of the YRD. Such programs will contribute to the management of chemicals and environment in YRD, with the potential to grow into the human health sector, and to expand to China as a whole. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 5: Submitted. Paper 6: Manuscript.</p><p> </p>
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Poluentes orgânicos e isótopos estáveis no ecossistema da Baía do Almirantado, Ilha Rei George, Antártida / Organic pollutants and stable isotopes in the ecosystem of Admiralty Bay, King George Island, AntarcticaCipro, Caio Vinicius Zecchin 21 November 2011 (has links)
Apesar da pequena influência antrópica direta em seu território, a Antártida não pode ser considerada livre do alcance de poluentes. No presente estudo, avaliou-se a distribuição e transferência de poluentes orgânicos (PCBs, pesticidas organoclorados e PBDEs) em compartimentos abióticos (neve e água de degelo) e bióticos (liquens, musgos, invertebrados, peixes, ovos de aves e tecidos de aves e pinípedes, para os quais também foi aplicada análise isotópica de nitrogênio-15 e carbono-13) do ecossistema da Baía do Almirantado. Os compartimentos abióticos tiveram concentrações entre 1,4 e 156 pg L-1, apenas para grupos de organoclorados, com variação intra-sazonal importante e compatibilidade com níveis tróficos inferiores e amostras de vegetação, que por sua vez refletiram a importância de fontes secundárias de poluentes. Nos animais, grosso modo, os compostos prevalecentes (em ng g-1 peso úmido) foram PCBs, (6,82-1821), HCB (0,060-136) e DDTs, (0,410-524), níveis de duas a três ordens de grandeza superiores aos encontrados em vegetação. PBDEs ocorreram, de modo geral, em níveis uma ou duas ordens de grandeza abaixo dos organoclorados. A análise isotópica mostrou-se útil como ferramenta indicadora de nível trófico e origem de matéria orgânica consumida, correlacionando-se quantitativa e qualitativamente com os poluentes orgânicos pela indicação de fatores como stress nutricional e mudança de área de forrageio e/ou de dieta. Como alternativa, foi proposto um novo indicador de biomagnificação baseado no peso molecular dos PCBs, que apresentou resultados estatisticamente superiores ao ?15N na maioria dos casos. / Despite the small antropic direct influence on its territory, Antarctica cannot be considered out of pollutants\' reach. The present study evaluated the distribution and transfer of organic pollutants (PCBs, organochlorine pesticides and PBDEs) in both abiotic (snow and melting water) and biotic (lichens, mosses, invertebrates, fishes, bird eggs and bird and pinnipeds\' tissues, for which was also applied carbon-13 and nitrogen-15 stable isotopes analyses) compartments of the ecosystem from Admiralty Bay. Abiotic compartments showed concentrations between 1,4 and 156 pg L-1, only for organochlorine groups, with considerable intraseasonal variation and compatibility with lower trophic levels and vegetation samples, which in turn reflected the importance of secondary pollutants sources. In animal samples, grosso modo, the prevailing compounds were (in ng g-1 wet weight) PCBs (6,82-1821), HCB (0,060-136) and DDTs, (0,410-524), levels from two to three orders of magnitude superior to the ones found in vegetations. PBDEs occurred, in a general way, in levels from one to two orders of magnitude lower than the organochlorines. Stable isotope analyses proved useful as an indicator tool for trophic level and consumed organic matter, correlating itself in a qualitative and quantitative way with the organic pollutants by indication of factors as nutritional strees and variation in foraging areas and/or diet. As an alternative, a new biomagnifications indicator based on PCBs molecular weight was proposed, showing results statistically superior to the ?15N in the majority of the cases.
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DESENVOLVIMENTO, VALIDAÇÃO E APLICAÇÃO DE UM MÉTODO QuEChERS PARA A DETERMINAÇÃO DE PESTICIDAS ORGANOCLORADOSStremel, Tatiana Roselena de Oliveira 12 April 2018 (has links)
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Previous issue date: 2018-04-12 / A maior parte dos pesticidas organoclorados (OCPs) possuem comercialização controlada ou proibida a décadas, no entanto são ainda encontrados em todos os locais do planeta. A determinação destes compostos em matrizes complexas como tecido de peixe é alvo constante de pesquisas, especialmente com o objetivo de minimizar consumo de reagentes e tempo. Este estudo objetivou desenvolver e validar um método QuECheRS com ultrassom e d-SPE para determinação por CG/ECD/MS de p,p’-DDE, p,p’-DDT, α-endosulfan, β-endosulfan, Aldrin e Dieldrin em tecidos de peixe, aplicar em amostras de tecidos de peixe comercializadas e em tecidos coletados em ambiente natural e realizar uma avaliação de risco das concentrações de OCPs detectadas nos tecidos. Três planejamentos fatoriais foram empregados para otimizar a etapa de preparo da amostra. O método desenvolvido foi validado para verificar seu desempenho e um possível efeito matriz, sendo posteriormente aplicado na extração de OCPs de músculo de Tilápia e Lambari comercializados em supermercados de Ponta Grossa e em músculo, ovas e vísceras de Lambari coletado da represa de Alagados, em Ponta Grossa. Ao final realizou-se uma avaliação de risco relacionando o consumo diário local, com massa corporal média da população e contaminação por OCPs nos tecidos analisados. Na validação o método apresentou recuperações entre 77,3% e 110,8%, com RSD inferior a 13% e os limites de detecção estiveram entre 0,24 μgkg-1 e 2,88μgkg-1, mostrando boa sensibilidade e precisão. Resíduos dos OCPs estudados foram detectados nos tecidos analisados em concentrações que variaram entre 3,4 μgkg-1 e 417,6 μgkg-1, verificando-se que os poluentes possuem uma tendência a bioacumular em maior proporção nas vísceras, do que em ovas e no músculo, a presença destes compostos nas ovas, demonstra que indivíduos da espécie analisada entram em contato com os OCPs desde a fase de embrião. Na avaliação de risco verificou-se que ao se consumir esses peixes, esses OCPs podem ao longo do tempo gerar efeitos adversos para a saúde dos consumidores. O método proposto mostrou-se efetivo na determinação de baixas concentrações de OCPs em tecidos de peixe, utilizando pequena massa de amostra (0,5 gramas), viabilizando a análise sem a necessidade de agrupamento (pool), ao mesmo tempo possibilitou a análise de tecidos, de peixe de pequena massa corporal total (Lambari), avaliando ainda a bioacumulação dos OCPs em diferentes tecidos. O método é aplicável para análise de OCPs aplicado à área toxicológica. / Most organochlorine pesticides (OCPs) are controlled or banned for decades, but they are still found everywhere in the world. The determination of these compounds in complex matrices such as fish tissue is a constant goal of research, especially with the aim of minimizing reagent consumption and time. The aim of this study was to develop and validate a Quechers method with ultrasound and d-SPE for determination of p, p'-DDE, p, p'-DDT, α-endosulfan, β-endosulfan, Aldrin and Dieldrin in fish tissues, apply on samples of commercially available fish tissues and on tissues collected in the natural environment and carry out a risk assessment of the concentrations of OCPs detected in the tissues. Three factorial designs were used to optimize the preparation stage of the sample. The method developed was validated through figures of merit and matrix effect, and it was later applied in the extraction of OCPs from Tilapia and Lambari muscle marketed in supermarkets in Ponta Grossa and Lambari muscle, eggs and viscera collected from the Alagados dam in Ponta Thick. At the end of the study, a risk assessment was performed relating local daily consumption, mean body mass of the population and OCP contamination in the tissues analyzed. In the validation, the method presented recoveries between 77.3% and 110.8%, with RSD lower than 13% and detection limits between 0.24 μg kg -1 and 2.88 μg kg -1, showing good sensitivity and precision. Residues of the OCPs studied were detected in the tissues analyzed at concentrations ranging from 3.4 μgkg-1 to 417.6 μgkg-1, with pollutants having a tendency to bioaccumulate more in the viscera than in roe and in muscle, the presence of these compounds in the eggs, demonstrates that individuals of the analyzed species come into contact with OCPs from the embryo stage. In the risk assessment it was found that there is a risk when consuming these fish, these OCPs may over time generate adverse effects on the health of consumers. The proposed method was effective in the determination of low concentrations of OCPs in fish tissues, using a small sample mass (0.5 grams), making the analysis possible without the necessity of pooling, at the same time making possible the analysis of tissues, of fish of small total body mass (Lambari), also evaluating the bioaccumulation of OCPs in different tissues. The method is promising for OCP analysis applied to the toxicological area.
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Poluentes orgânicos persistentes e ingestão de plásticos em albatrozes e petréis (Procellariiformes) / Persistent organic pollutants and plastic ingestion in albatrosses and petrels (Procellariiformes)Colabuono, Fernanda Imperatrice 04 August 2011 (has links)
Os albatrozes e petréis (Procellariiformes) são aves oceânicas e migratórias de grande interesse conservacionista. Neste trabalho foram estudadas duas classes de poluentes bastante conhecidos por afetarem negativamente as aves marinhas: os poluentes orgânicos persistentes e os plásticos. Bifenilos policlorados (PCBs) e pesticidas organoclorados foram detectados no tecido adiposo, fígado e músculo de oito espécies de Procellariiformes. Apesar da grande variabilidade intraespecífica nas concentrações, os perfis de PCBs e pesticidas organoclorados foram semelhantes entre os indíviduos, com predôminância de PCBs penta, hexa e heptaclorados e do p´p-DDE. A condição corporal se mostrou um fator importante na variação e redistribuição dos organoclorados nos tecidos das aves. As análises de isótopos estáveis de carbono e nitrogênio no fígado e músculo das aves mostraram que a dieta não foi suficiente para explicar as concentrações de organoclorados nas espécies estudadas e reforçaram a influência de fatores como idade, distribuição e especifidade da dieta na contaminação por estes compostos em aves marinhas. PCBs e pesticidas organoclorados foram detectados em pellets e fragmentos plásticos encontrados no trato digestório das aves estudadas, com perfis semelhantes aos encontrados nos tecidos dos Procellariiformes. A ocorrência de poluentes orgânicos em plásticos evidencia a capacidade destes de adsorver e transportar estes compostos e reforça o potencial dos plásticos como uma fonte adicional de contaminação para os animais que os ingerem, como as aves marinhas. / Albatrosses and petrels (Procellariiformes) are migratory oceanic birds of considerable conservational interest. The aim of the present study was to evaluate two classes of pollutants that negatively affect seabirds: persistent organic pollutants and plastics. Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were detected in the adipose tissue, liver and muscle of eight species of Procellariiformes. Although organochlorine concentrations exhibited a high degree of intra-species variability, the profiles of PCBs and OCPs were similar among the individuals, with predominance of penta, hexa and heptachlorobiphenyls and p´p-DDE. Body condition was an important factor in the variation and redistribution of organochlorine compounds in the tissues of the birds. Stable isotope analysis of carbon and nitrogen in the liver and muscle revealed that diet alone was insufficient to explain the organochlorine concentrations in the species studied, suggesting the influence of factors such as age, distribution and diet specificity regarding organochlorine contamination in seabirds. PCBs and OCPs were detected in plastic fragments and pellets found in the digestive tract of Procellariiformes, with profiles very similar to those found in the tissues of the birds. The occurrence of organic pollutants in plastics demonstrates their ability to adsorb and transport these compounds and underscores the potential of plastics as an additional source of contamination in organisms that ingest these products, such as seabirds.
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In Utero Exposure to Organochlorine Pesticides and Early Menarche in the Avon Longitudinal Study of Parents and ChildrenNamulanda, Gonza, Maisonet, Mildred, Taylor, Ethel, Flanders, W. Dana, Olsen, David, Sjodin, Andreas, Qualters, Judith R., Vena, John, Northstone, Kate, Naeher, Luke 01 September 2016 (has links)
Introduction
Epidemiologic data supporting the role of organochlorine pesticides in pubertal development are limited.
Methods
Using a nested case-control design, serum collected during pregnancy from mothers of 218 girls who reported menarche before 11.5 years of age (cases) and 230 girls who reported menarche at or after 11.5 years of age (controls) was analyzed for 9 organochlorines and metabolites. We analyzed the association between in utero organochlorine concentrations and early menarche using multivariate logistic regression controlling for mother's age at menarche, or mother's prenatal BMI.
Results
We did not observe an association between in utero exposure to HCB, β-HCH, ϒ-HCH, p,p′-DDT, p,p′-DDE, oxychlordane or trans-nonachlor and early menarche.
Conclusions
This study is the first to examine the association between in utero exposure to HCB, β-HCH, ϒ-HCH, oxychlordane or trans-nonachlor and early menarche. In utero exposure to organochlorine pesticides does not appear to have a role in the timing of menarche in this study.
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