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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Estudo de biodisponibillidade de Hidrocarbonetos Policíclicos Aromáticos - HPAs na água do mar nos ecosistemas marinhos do Sistema Estuarino de Santos - São Vicente e do sistema estuarino-lagunar de Cananéia-Iguape / Bioavailability of Polycyclic Aromatic Hydrocarbons - PAHs in the sea water in Santos Estuarine System and Cananéia - Iguape Lagoon System

Fabiana Ribeiro Fontenelle da Silva 02 March 2018 (has links)
O objetivo deste trabalho foi avaliar a biodisponibilidade de HPAs na água do mar no sistema estuarino de Santos e no sistema lagunar de Cananéia-Iguape, para isso foi feita a exposição de membranas semipermeáveis (SPMD) e de bivalves (Crassostrea brasiliana) a fim de se obter um melhor panorama das concentrações desse poluente nessas duas regiões. De forma complementar foram analisadas também amostras de água, material particulado em suspensão (MPS) e sedimentos. A bioacumulação de HPAs no tecido de bivalves foi cerca de quatro vezes superior às suas concentrações iniciais para a região de Santos. Foram também estimadas as concentrações de HPA na água do mar através das concentrações encontradas nos SPMDs e nos bivalves transplantados. Essas concentrações foram comparáveis às concentrações encontradas nas amostras de água. Através da análise de componentes principais juntamente com índices diagnósticos foi possível estabelecer as possíveis fonte de HPAs para as matrizes analisadas, identificando assim a predominância de HPAs pirolíticos em bivalves e sedimentos, enquanto que na água, MPS e SPMDs há predominância de HPAs petrogênicos. A comparação entre compartimentos mostrou a importância da avaliação de múltiplas matrizes, em função da concentração de HPAs cada grupo de compostos e de seus diferentes padrões de acumulação. Não foram observadas diferenças significativas entre as concentrações médias de HPAs nas duas regiões de estudo. O Complexo de Cananéia - Iguape antes considerada como área controle, apresentou concentrações de HPAs elevadas, indicando influencia antrópica para a região. / The aim of this work was to evaluate PAH\'s bioavailability in the sea water in Santos Estuarine System and Cananéia - Iguape Lagoon System. SemiPermeable Membrane Devices (SPMD) and bivalves (Crassostrea brasiliana) were deployed in both areas to obtain an overview of all these pollutants concentration, further than the potential of bioaccumulation of contaminants. Aiming comparative purposes, samples of water, suspended particulate matter (SMP) and sediments were also analyzed. PAHs bioaccumulation in bivalves tissues after deployment represented fourfold the initial concentration for Santos region. The estimated concentration of 16 priority PAHs in the water SPMD- and bivalve-based were within the concentration of PAH analyzed in the water samples, demonstrating the effectiveness of those tools to assessment of PAH in water. Through the Principal Components Analysis (PCA), and the diagnostic ratios it was possible to establish the potential sources of PAHs for analyzed compartments, identifying the pyrolytic PAH influence for bivalves and sediments under, while for water, MPS and SPMDs the mainly PAHs source were from petrogenic PAHs. Comparison between compartments showed the importance of multiple tools analyzes due to the concentration of PAH of each compound group and the different pattern of accumulation. It was not observed significant difference between the mean concentrations of PAHs in both studied regions. Cananéia - Iguape Complex was first considered as control area reported PAHs concentration higher PAH concentrations, suggesting anthropic influence in this area.
182

A study of particulate matter pollutants in the Canberra air shed, including total suspended particles PM10, lead and polycyclic aromatic hydrocarbons

Fox, Ian, n/a January 1998 (has links)
Methods for the determination of Polycyclic Aromatic Hydrocarbons (PAHs) associated with suspended participate matter were developed with the aim of determining airborne concentrations and to investigate seasonal trends. Other associate pollutants such as Total Suspended Particulate matter (TSP), Particulate Matter with an equivalent aerodynamic diameter less than 10 micrometres (PM10) and lead concentration were also reviewed to determine trends. Motor vehicle emissions appear to be the source of the PAHs and differences between the types and concentrations of PAHs detected at central business district sites verses suburban sites were noted. Wind erosion, biomass burning, motor vehicle emissions and industrial processes are sources of particulate matter in the atmosphere. Lead comes mainly from motor vehicles emissions in the ACT with some lead possibly from the burning of lead contaminated fuel. TSP and lead concentrations have decreased since air quality monitoring began in the early 1980s. PM10 concentration may also have fallen but the data set for PM10s is to small to draw any firm conclusions. Only TSP lead concentrations displayed a seasonal pattern. The ACT air pollution Act 1984 has placed restriction on the burning of fuels to improve air quality in the ACT. The air quality in regards to TSP and lead is improving. However, the only strong links between the Act and decreased pollutant concentrations is the introduction of unleaded petrol and the decrease of airborne lead concentrations.
183

Materials for Hydrogen storage and synthesis of new materials by hydrogenation / Material för vätelagring och syntes av nya material genom hydrering

Luzan, Serhiy January 2012 (has links)
The search for new materials for hydrogen storage is important for the development of future hydrogen energy applications. In this Thesis, it is shown that new materials with interesting properties can be synthesized by the reaction of hydrogen with various nanocarbon precursors. The thesis consists of two parts. The first part is devoted to studies of hydrogen storage in some metal-organic frameworks (MOFs) and nanostructured carbon materials, while the second part describes synthesis of new materials by the reaction of hydrogen gas with various carbon materials (i.e. fullerene C60, single-walled carbon nanotubes (SWCNTs), and fullerene C60 encapsulated inside SWCNTs (C60@SWCNTs)). Hydrogen adsorption was measured for a set of Zn- and Co-based MOFs at near ambient temperatures. MOFs synthesized using different metal clusters and organic connecting ligands allowed to study effects of different surface area, pore volume, and pore shapes on hydrogen storage parameters. Hydrogen adsorption values in the studied MOFs correlated well with surface area and pore volume but did not exceed 0,75wt.%. Therefore, new methods to improve the hydrogen storage capacity in MOFs were investigated. The addition of metal catalysts was previously reported to improve significantly hydrogen storage in MOFs. In this thesis the effect of Pt catalyst addition on hydrogen adsorption in MOF-5 was not confirmed. Contrary to previous reports, hydrogen adsorption in MOF-5 mixed/modified with Pt catalysts had fast kinetics, correlated well with surface area, and was on the same level as for unmodified MOF-5. New nanostructured carbon materials were synthesized by the reaction between fullerene C60 and coronene/anthracene. Despite negligible surface area these materials adsorbed up to 0,45wt.% of hydrogen at ambient temperatures. The reaction of fullerene C60 with hydrogen gas was studied at elevated temperatures and hydrogen pressures. In situ gravimetric monitoring of the reaction was performed in a broad temperature interval with/without addition of metal catalysts (i.e. Pt and Ni). The reaction resulted in synthesis of hydrogenated fullerenes C60Hx (with x≤56) followed by fullerene cage fragmentation and collapse upon prolonged duration of hydrogen treatment. Possible mechanisms of C60 hydrogenation and fragmentation were discussed. It is demonstrated that reaction of SWCNTs with hydrogen gas at elevated temperatures and hydrogen pressures can be used for nanotube opening, purification from amorphous carbon, side-wall hydrogenation, and partial unzipping of SWCNTs. Some graphene nanoribbons (GNRs) were synthesized as the result of SWCNTs unzipping. A surprising ability of hydrogen to penetrate inside SWNTs and to react with encapsulated fullerene C60 was demonstrated. / Sökandet efter nya material för vätelagring är viktigt för utveckling av framtida väteenergitillämpningar. I denna avhandling visas att nya material med intressanta egenskaper kan syntetiseras genom reaktion av väte med olika nanokolprekursorer. Avhandlingen består av två delar. Den första delen ägnas åt studier av vätelagring i vissa metall-organiska fackverk (så kallade MOFs) och nanostrukturerade kolmaterial medan den andra delen beskriver syntes av nya material genom reaktion av vätgas med olika kolmaterial (dvs. fulleren C60, enkelväggiga kolnanorör (SWCNTs) och fulleren C60 kapslat i SWCNTs (C60 @ SWCNTs)). Väteadsorptionen mättes för ett antal Zn- och Co-baserade MOFs vid rumstemperatur. MOFs syntetiserades med hjälp av olika metallkluster och organiska ligander för att studera effekterna av olika yta, porvolym och porformer på vätelagringsparametrarna. Väteadsorptionsvärden i de studerade MOFs korrelerade väl med yta och porvolym, men översteg inte 0,75wt.%. Därför undersöktes nya metoder för att förbättra kapaciteten för vätelagring i MOFs. Tillsättning av metallkatalysatorer har tidigare rapporterats avsevärt förbättra vätelagring i MOFs. I denna avhandling kunde effekten av en tillsats av Pt-katalysator på väteadsorption i MOF-5 inte bekräftas. I motsats till tidigare rapporter hade väteadsorption i MOF-5 blandad/modifierad med Pt-katalysatorer snabb kinetik och korrelerade väl med arean, men var på samma nivå som för omodifierad MOF-5. Nya nanostrukturerade kolmaterial syntetiserades genom reaktion mellan fulleren C60 och coronene/antracene. Trots försumbar yta adsorberade dessa material upp till 0,45wt.% väte vid rumstemperatur. Reaktionen av fulleren C60 med vätgas studerades vid förhöjda temperaturer och vätetryck. In situ gravimetrisk övervakning av reaktionen utfördes i ett brett temperaturintervall med/utan tillsats av metallkatalysatorer (dvs. Pt och Ni). Reaktionen resulterade i syntes av hydrogenerade fullerener C60Hx (med x≤56) följt av fragmentering och kollaps av fullerenstrukturen vid förlängd varaktighet av vätebehandlingen. Möjliga mekanismer för hydrering och fragmentering av C60 diskuteras. Det har visats att reaktionen mellan SWCNTs och vätgas vid förhöjda temperaturer och vätetryck kan användas för öppning av nanorör, borttagning av amorft kol, funktionalisering av sidoväggar och partiell "blixtlåsöppning" av SWCNTs. Reaktionen kan också syntetisera grafen-nanoband (GNRs) som en följd av att SWCNTs öppnas på längden. En överraskande stor förmåga för väte att tränga in i SWNT och där reagera med inkapslade fullerenmolekyler C60 demonstrerades.
184

Sources and concentration distribution of polycyclic aromatic hydrocarbons in sediment cores of Fangliao submarine canyon

Yang, Fu-yun 01 July 2009 (has links)
This study investigated the concentration distributions of polyclic aromatic hydrocarbons (PAHs) in the sediment cores collected from Fang-Liao submarine canyon. Chemical fingerprinting techniques and statistical analysis were applied to delineate the possible sources of the PAHs in deposited sediment core samples. It is noteworthy that all cores were not dated; therefore the deposition age could not estimate from the depth of deposition directly. The average concentrations of polyclic aromatic hydrocarbons (£U51PAHs) were found ranged from 229 to 638 (ng/g dry wt) in the sediment cores in Fang-Liao submarine canyon. In addition, the low molecular weight PAHs (2-3 ring PAHs) were found dominant in the PAH composition pattern of most samples. Total PAH concentrations were significantly correlated with total organic carbon (TOC) in all the sediment cores. Compared with sediment quality guidelines (SQGs), the PAH concentrations of all sediment samples were lower than those outlined in the criteria, that suggests no evident adverse biological effects caused by PAHs. Results also showed that total PAH concentration of surface sediments (0-2 cm) decreased with the water depth. Identification of PAHs sources suggests that all up-cores were dominated by petrogenic sources, but all down-cores except for S17 and S18 were dominated by pyrogenic sources or mixed sources. In contrast, biogenic sources were found dominant in S17 and S18 as they were characterized by higher ratio of perylene/£Upenta-PAHs(%). Compared with literature, the sediment cores of Fang-Liao submarine canyon were moderately polluted with PAHs. Analysis of diagnostic ratios and hierarchical cluster analysis (HCA) as well as principal component analysis (PCA) all indicate PAHs sources of Fang-Liao submarine canyon were mainly from petroleum and petroleum combustion sources for site of S3,S5,S7,S8 and S17; while pyrogenic or mixed sources for site of S1,S2,S9,S18 and S33.
185

Avaliação de adsorventes sólidos para a remoção de derivados de HPAs em solução / Evaluation of solid adsorbents for removal of derivatives PAHs in solution

Colim, Alexsandro Nunes 12 March 2014 (has links)
Polycyclic aromatic hydrocarbons, nitrogen and oxygen (Nitro-PAHs and Oxy-PAHs) compose the class of compounds where a hetero atom of nitrogen and oxygen, respectively, is present in the constitution of the HPA. The inclusion of a heteroatom leads to increased mobility and increased toxicological potential. In this work were investigated adsorbent materials for removal of Nitro-PAH and Oxy-PAH from aqueous solutions. For this purpose, activated carbon (AC), polyurethane foam (PUF), quartz fiber (QF), high density polyethylene (PEHD), polytetrafluoroethylene Teflon (PTFE), Amberlite XAD-2 (XAD-2) and silica gel (Si), were evaluated as potential solid substrates, as well as its use as an alternative to XAD -2 for making personal samplers type lapel. Quinoline, 1-nitronaphthalene, Acridine, Phenazine, 2-nitrofluorene, 9-nitroanthracene and 1-nitropyrene were chosen as representatives of the class of compounds Nitro-PAHs. 2-naphthol, 2-hydroxyfluorene, Phenanthrene-9-carboxaldehyde, 9,10-anthraquinone, and 1-hydroxypyrene were chosen as representatives of the class of compounds Oxy-PAHs. The results were obtained by batch tests. For Nitro-PAHs, the adsorbents with the highest removal rates were: XAD-2 (100% removal on XAD-2, except for Quinoline - 80%) and activated carbon (around 90% for all reviews compounds). For Oxy-PAHs, the highest removal rates were provided by adsorbents: polyurethane foam and activated carbon, both with rates higher than 90% of removal. Due to the low solubility of the compounds, the presence of a co-solvent is required. The lowest temperature (20 ⁰C) favored the adsorption of the compounds. In general, both (Nitro-PAHs and Oxy-PAHs) classes have their removal influenced by increasing the concentration of the solute in solution. / Hidrocarbonetos policíclicos aromáticos nitrogenados e oxigenados (Nitro-HPAs e Oxi-HPAs) compõem a classe de compostos onde um heteroátomo de nitrogênio e oxigênio, respectivamente, esta presente na constituição do HPA. A inserção do heteroátomo acarreta numa maior mobilidade e aumento do potencial toxicológico. Neste trabalho foram investigados materiais adsorventes para a remoção de Nitro-HPAs e Oxi-HPAs a partir de soluções aquosas. Para isto, carvão ativado, espuma de poliuretano, fibra de quartzo, polietileno de alta densidade, politetrafluoretileno (teflon), Amberlite XAD-2 e sílica gel, foram avaliados como possíveis substratos sólidos. Quinolina, 1-nitronaftaleno, Acridina, Fenazina, 2-nitrofluoreno, 9-nitroantraceno e 1-nitropireno foram escolhidos como representantes à classe de compostos Nitro-HPAs. 2-naftol, 2-hidroxifluoreno, Fenantreno-9-carboxaldeído, 9,10-antraquinona e 1-hidroxipireno foram escolhidos como representantes à classe de compostos Oxi-HPAs. Os resultados foram obtidos através de ensaios em batelada. Para os Nitro-HPAs estudados, os adsorventes que apresentaram as maiores taxas de remoção foram: XAD-2 (100% de remoção em XAD-2, exceto pra Quinolina 80%) e carvão ativado (em torno de 90% para todos os compostos avaliados). Para os Oxi-HPAs estudados, as maiores taxas de remoção foram proporcionadas pelos adsorventes: espuma de poliuretano e carvão ativado, ambos com taxas de remoção superiores a 90%. Devido à baixa solubilidade dos compostos, a presença de um co-solvente se faz necessária. A temperatura mais baixa (20 ⁰C) favoreceu a adsorção dos compostos. De modo geral, ambas as classes (Nitro-HPAs e Oxi-HPAs) tem sua remoção influenciada pelo aumento da concentração do soluto em solução.
186

Hidrocarbonetos policíclicos aromáticos (HPAs) em organismos marinhos da Baía do Almirantado, Península Antártica / Polyclyclic aromatic hydrocarbons (PAHs) in marine organisms from the Admiralty Bay, Antartic Peninsula

Hiléia dos Santos Barroso 03 November 2010 (has links)
As concentrações de HPAs foram analisadas em invertebrados (Laternula elliptica, Nacella concinna, Yoldia eightsi, Glyptonotus antarcticus, Serolis polita, Euphausia superba, Bovalia gigantea, Sterechinus neumayeri, Odontaster validus e Ophionotus victoriae), peixes (Notothenia rossii), e aves (Pygoscelis Adélia, P. papua, P. antarcticus, Macronectes giganteus, Catharacta sp. e Larus dominicanus) da Baía do Almirantado. As análises de HPAs foram realizadas através de GC/MS. A ocorrência de HPAs nas amostras indicou a biodisponibilidade destes compostos para os organismos da região. As concentrações de HPAs totais para os invertebrados (3,09-174,4 ng g -1 pu) foram maiores que em peixes (0,97-58,9 ng g -1 pu) e menores que em aves (60,1-6861,0 ng g-1 pu), porém apresentaram similaridade entre si. As aves voadoras adultas apresentaram maiores concentrações que os pinguins. Compostos leves e alquilados predominaram em quase todas as amostras, principalmente os alquilnaftalenos. A principal fonte de HPAs para os organismos foi o DFA utilizado na EACF. Espécies predadoras/necrófagas apresentaram HPAs individuais diferentes das espécies suspensívoras/depositívoras. Não ocorreu relação entre o aumento da concentração de HPAs e o aumento do nível trófico dos grupos, e a absorção de HPAs pelas espécies sofreu a influência de fatores como metabolismo, fisiologia, hábito alimentar e teor de lipídio das espécies analisadas. / The concentrations of PAHs had been analyzed in invertebrates (Laternula elliptica, Nacella concinna, Yoldia eightsi, Glyptonotus antarcticus, Serolis polita, Euphausia superba, Bovalia gigantea, Sterechinus neumayeri, Odontaster validus and Ophionotus victoriae), fish (Notothenia rossii) and birds (Pygoscelis adélia, P. papua, P. antarcticus, Macronectes giganteus, Catharacta sp. and Larus dominicanus) Admiralty Bay. The analyses of HPAs had been carried through GC/MS. The occurrence of PAHs in the samples indicated the bioavailability of these compounds for the organisms of the region. The concentration of total PAHs for the invertebrates (3,09 to 174,4 ng g-1 pu) were higher than fish (0,97 to 58,9 ng g-1 pu) and lower than in birds (60,1- 6861,0 ng g-1 pu) however, they had presented similarity between themselves. The adult flying birds had presented higher concentrations than penguins. Light and alkylated compounds had predominated in almost all samples, mainly the alkylnaphthalenes. The main source of PAHs for the organism was the DFA used in the EACF. Predators/necrophagous species had presented different individual PAHs from the feeder/deposit species. There was no relation between the increase of concentrations of PAHs and the increase of the trophic level of the groups, and the absorption of PAHs for the species had the influence of factors such as metabolism, physiology, alimentary habits and lipid content of the analyzed species.
187

Genotoxicidade e composi??o do material particulado emitido pela queima de Biomassa: um estudo de caso em Tangar? da Serra, Regi?o da Amaz?nia Brasileira

Alves, Nilmara de Oliveira 10 March 2010 (has links)
Made available in DSpace on 2014-12-17T14:03:32Z (GMT). No. of bitstreams: 1 NilmaraOA_DISSERT.pdf: 973929 bytes, checksum: a34dad87199547e8eb7f5ac9e8e30f9b (MD5) Previous issue date: 2010-03-10 / Universidade Federal do Rio Grande do Norte / Tangara da Serra is located on southwestern Mato Grosso and is found to be on the route of pollutants dispersion originated in the Legal Amazon s deforestation area. This region has also a wide area of sugarcane culture, setting this site quite exposed to atmospheric pollutants. The objective of this work was to evaluate the genotoxicity of three different concentrations of organic particulate matter which was collected from August through December / 2008 in Tangara da Serra, using micronucleus test in Tradescantia pallida (Trad-MCN). The levels of particulate matter less than 10μm (MP10) and black carbon (BC) collected on the Teflon and polycarbonate filters were determined as well. Also, the alkanes and polycyclic aromatic hydrocarbons (PAHs) were identified and quantified on the samples from the burning period by gas chromatography detector with flame ionization detection (GC-FID). The results from the analyzing of alkanes indicate an antropic influence. Among the PAHs, the retene was the one found on the higher quantity and it is an indicator of biomass burning. The compounds indene(1,2,3-cd)pyrene and benzo(k)fluoranthene were identified on the samples and are considered to be potentially mutagenic and carcinogenic. By using Trad-MCN, it was observed a significant increase on the micronucleus frequency during the burning period, and this fact can be related to the mutagenic PAHs which were found on such extracts. When the period of less burnings is analyzed and compared to the negative control group, it was noted that there was no significant difference on the micronuclei rate. On the other hand, when the higher burning period is analyzed, statistically significant differences were evident. This study showed that the Trad-MCN was sensible and efficient on evaluating the genotoxicity potencial of organic matter from biomass burning, and also, emphasizes the importance of performing a chemical composition analysis in order to achieve a complete diagnosis on environmental risk control / Tangar? da Serra est? situada no sudoeste do Mato Grosso e encontra-se no trajeto de dispers?o de poluentes provenientes da ?rea do arco do desmatamento da Amaz?nia Legal. A regi?o tamb?m possui uma extensa ?rea de plantio de cana-dea??car, configurando um local de exposi??o a poluentes atmosf?ricos. O objetivo deste trabalho foi avaliar a genotoxicidade do material particulado (MP) org?nico, em tr?s diferentes concentra??es, coletado nos meses de agosto a dezembro / 2008 em Tangar? da Serra atrav?s do teste de micron?cleo em Tradescantia (Trad-MCN). Al?m disso, foram determinados os n?veis do material particulado menor que 10μm (MP10) e black carbon (BC) coletados nos filtros teflon e de policarbonato. Foram identificados e quantificados nas amostras do per?odo de queima, os alcanos e os hidrocarbonetos polic?clicos arom?ticos (HPAs) atrav?s da cromatografia gasosa acoplada ao detector de ioniza??o de chama (CG-DIC). Os resultados da an?lise dos alcanos indicam influ?ncia antr?pica. Dentre os HPAs, o reteno foi encontrado em maior quantidade e ? um marcador de queima de biomassa. Os compostos indeno (1,2,3,-cd)pireno e benzo(k)fluoranteno foram identificados nas amostras e s?o considerados potencialmente carcinog?nicos e mutag?nicos. Atrav?s do Trad-MCN, observou-se um aumento significativo na frequ?ncia de micron?cleo no per?odo de queima e este fato pode estar relacionado com os HPAs mutag?nicos encontrados nesses extratos. Ao analisar o per?odo de menor queima, constatou-se que n?o h? diferen?a significativa na taxa de micron?cleo quando comparado com o controle negativo e mostraram diferen?as estatisticamente significativas com rela??o ao grupo de maior queima. Este estudo mostrou que o Trad-MCN foi sens?vel e eficiente na avalia??o do potencial genot?xico do material org?nico proveniente da queima de biomassa, enfatizando a import?ncia da an?lise da composi??o qu?mica, para que assim seja poss?vel facilitar os mais completos diagn?sticos no controle dos riscos ambientais
188

Mutagênese ambiental: estabelecimento de valores de referência para manguezais da Baía de Ilha Grande / Environmental mutagenesis: establishment of reference valves for mangroves of Ilha Grande Bay

Ana Maria Azevedo Velho 28 February 2011 (has links)
Estudos ambientais têm demonstrado que substâncias geradas por processos antropogênicos podem causar efeitos prejudiciais interferindo no equilíbrio natural do ecossistema. Manguezais exercem funções essenciais nos ciclos biológicos e constituem Área de Proteção Permanente no Brasil. Infelizmente, eles estão sendo degradados acima do seu limite de suporte, levando a uma redução das áreas remanescentes no mundo. Este trabalho apresenta os resultados de mutagenicidade e genotoxicidade observados em quatro amostragens (PI, V, O e PII) entre 2009 e 2010, relacionados com metais e hidrocarbonetos policíclicos aromáticos (HPA) em sedimento de mangue para a caracterização dos valores de referência. Os testes de genotoxicidade foram feitos a partir de hemócitos do caranguejo Goniopsis cruentata, coletados em um ecossistema potencialmente não poluído do Brasil, localizado no sul do Rio de Janeiro (Parati/RJ), chamado de "Saco do Mamanguá". Coleta, armazenamento e manipulação dos sedimentos e material biológico de cinco pontos de amostragem (M1- M5) foram processados de acordo com normas norte-americanas reconhecidas. A identificação das substâncias químicas foi realizada com extratos de sedimentos e utilizada no bioensaio Salmonella/microssoma (Kado). A avaliação de potenciais danos genotóxicos estabelecidos foi realizada através do Teste de Micronúcleo, que apresentou valores significativos na amostra V. Resultados negativos foram observados para as cepas de Salmonella typhimurium TA97, TA98, TA100 e TA102, tanto na ausência quanto na presença de fração de metabolização exógena de mamíferos (S9 mix 4%) em todas as análises. A quantificação por cromatografia gasosa com detecção por espectrometria de massas dos 16 HPA prioritários em termos de conservação ambiental apresentou valores baixos nas duas primeiras amostragens (PI e V) e nulos nas coletas seguintes (O e PII), nos mesmos pontos. De acordo com os valores utilizados nos Estados Unidos e Canadá como referência, os detectados por nós não são considerados como toxicantes ambientais positivos, com exceção do Benzo(a)pireno, que em M1V apresentou valores um pouco acima do limite a partir do qual já podem ser observados pequenos efeitos na biota. A análise dos metais (Cd, Cr, Cu, Fe, Mn, Ni, Pb e Zn) por Espectrometria de Absorção Atômica inicialmente realizada com a água intersticial foi melhor interpretada a partir da matriz sedimento. Este estudo contribuirá com a implementação de indicadores para valores de referência em mangue. / Environmental studies have shown that substances generated by anthropogenic processes can cause adverse effects by interfering with the ecosystem natural balance. Mangroves perform essential functions in biological cycles and are Permanent Protection Area in Brazil. Unfortunately, they are being degraded above its support limit, leading to a reduction of the remaining areas in the world. This paper presents the results of mutagenicity and genotoxicity observed in four samples (PI, V, O, and PII) between years 2009 and 2010 linked to metals and polycyclic aromatic hydrocarbons (PAHs) in mangrove sediment in order to characterize reference values. The genotoxicity tests were made from the hemocytes Goniopsis cruentata collected in a potential unpolluted ecosystem of Brazil, located in the southern Rio de Janeiro (Parati/RJ), called "Saco do Mamanguá. Collection, storage, manipulation of sediment and biological material from five sampling sites (M1-M5) were processed according to U.S. standards recognized. The identification of the chemicals was performed with extracts of sediments and bioassay used in the Salmonella / microsome (Kado). The assessment of potential genotoxic damage were done down through the Micronucleus Test, and showed significant values in the sample V. Negative results were observed for the Salmonella typhimurium strains TA97, TA98, TA100 and TA102, both in the absence or presence of exogenous fraction of mammalian metabolism (S9 mix 4%) for all analysis. Quantification by Gas chromatography-mass spectrometry of the 16 priority PAHs in terms of environmental conservation, presented low values in the first two samples (V and PI) and null value in the following collections (and the IIP), in the same points. According to United States and Canada references, we detected chemicals not regarded as a positive environmental toxicants, with the exception of benzo(a)pyrene, which showed values in M1V just above the threshold at which already small effects can be observed in the biota. The analysis of metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) by Atomic Absorption Spectrometry initially performed with the pore water was best interpreted from the sediment matrix. This study will contribute to the implementation of indicators to benchmarks in the swamp.
189

\"Desenvolvimento de metodologia analítica para a determinação de hidrocarbonetos policíclicos aromáticos (PAHs) em amostras de água utilizando uma interface SPME/HPLC/DAD\" / \"Development of an analytical methodology for polycyclic aromatic hydrocarbons (PAH\'s) analysis in water samples using a SPME/LC/DAD interface\"

Fernanda Cristine Spoljaric Ferreira 20 March 2006 (has links)
Este trabalho descreve a otimização e validação de um método analítico para a análise de hidrocarbonetos policíclicos aromáticos (PAHs) em água usando uma interface SPME/LC/DAD. Parâmetros como tipos de fibra, tempo de extração, temperatura e força iônica foram estudados no modo \"off line\" e a influência destes na eficiência de extração foi avaliada. Os melhores resultados foram obtidos com a fibra Carbowax/templeted resin. Uma interface \"lab made\" foi utilizada para a etapa de validação e as curvas de calibração mostraram boa linearidade (r>0,99) para a maioria dos compostos analisados, tanto na linearidade da amostra como na linearidade do padrão. Os dados de precisão obtidos na concentração de trabalho variaram de 1 a 3%, aproximadamente, e os valores de recuperação se mantiveram na faixa de 4 a 27%. Os PAHs foram determinados na faixa de 0,025 micro g até 0,5 micro g. Pode-se considerar os valores obtidos nos itens de precisão e linearidade satisfatórios para a análise dos PAHs, considerando-se os critérios internacionais estabelecidos para esta classe de compostos, mas o método não atende as especificações relacionadas a recuperação e faixa de concentração. / This work describes the optimization and validation of an analytical method to determine Polycyclic Aromatic Hydrocarbons (PAHs) in water using a SPME/LC/DAD interface. Parameters as fibers kind, sampling time, temperature and ionic strength were studied and their influence on the extraction efficiency were evaluated. The best results were obtained with the Carbowax/templeted resin fiber. A \"lab made\" interface was used to validate the method and the calibration curves showed good linearity (r > 0,99) to almost all the compounds analyzed, considering both the sample linearity and the standard linearity. The data obtained for precision showed a variation from 1 to 3 % and the recovery values were bellow 27%. The PAHs analysis was performed for concentrations from 0,025 micro g/fiber to 0,5 micro g/fiber. The method does not show good recoveries values but the data obtained for precision and linearity can be considered satisfactory according to international criteria established for theses compounds.
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Óleos vegetais extraídos a frio comercializados na cidade de São Paulo: avaliação das características de identidade e qualidade e da ocorrência de hidrocarbonetos policíclicos aromáticos / Cold-pressed vegetable oils sold in São Paulo city: characteristics of identity and quality evaluation and polycyclic aromatic hydrocarbons occurrence

Simone Alves da Silva 13 November 2015 (has links)
O crescente mercado dos produtos naturais, fomentado pelo interesse dos consumidores por alimentos que auxiliem a promoção da saúde, tem pressionado a indústria alimentícia na oferta por novos alimentos. Dentre estes alimentos, encontram-se os óleos vegetais extraídos a frio, reconhecidos por preservarem compostos bioativos característicos e, alguns deles, serem fontes de ácidos graxos (AG) essenciais. A categoria dos óleos e gorduras apresenta, dentre outros alimentos, uma importante fonte de exposição aos hidrocarbonetos policíclicos aromáticos (HPAs), um grupo de contaminantes químicos orgânicos, alguns com ação carcinogênica. Este trabalho teve como objetivo avaliar os óleos vegetais extraídos a frio quanto aos parâmetros de identidade, de qualidade e à ocorrência de HPAs. Foram avaliadas 40 amostras, dez de cada tipo (coco, cártamo, prímula e linhaça), de diferentes marcas, adquiridas no comércio da cidade de São Paulo. Foram realizados os ensaios de perfil de AG, índice de acidez, índice de peróxido, p-anisidina, valor total de oxidação (totox) e HPAs (benzo(a)antraceno, criseno, benzo(b)fluoranteno e benzo(a)pireno). Quanto aos AG, catorze óleos (35 por cento ) não apresentaram perfis de ácidos graxos característicos que os declarados em seus rótulos, incluindo um de coco, quatro de cártamo e nove de prímula. Os valores para acidez estavam inadequados em relação a legislação para três óleos de linhaça (7,5 por cento ). Para o peróxido, quatro óleos (10 por cento ) estavam acima do limite da legislação, sendo dois de linhaça e dois de prímula. Os valores de p-anisidina variaram de <LQ a 12,98, sendo o menor valor encontrado nas amostras de coco e o maior em uma de prímula, que apresentava um odor alterado. No ensaio de totox, 37,5% das amostras apresentaram valores acima da recomendação da literatura, especialmente os óleos de cártamo e prímula. Já para os HPAs, pelo menos um dos hidrocarbonetos analisados foi detectado em 97,5% das amostras avaliadas; três amostras de prímula (7,5%) apresentaram níveis acima do permitido pela Comunidade Européia para BaP e, para a soma dos 4 HPAs, oito óleos (20%) estavam em desacordo: dois de cártamo, quatro de prímula e dois de linhaça. Este trabalho expõe os problemas relacionados aos parâmetros de identidade, qualidade e contaminação dos óleos vegetais comercializados como extraídos a frio e reforçam a importância de um contínuo monitoramento destes produtos. / The natural product market growth, stimulated by the interest of consumers in foods that support health promotion, has encouraged the food industry to supply new kinds of foods. Among these are the cold-pressed vegetable oils, recognized by preserving characteristic bioactive compounds and, some of them, are sources of essential fatty acids (FA). The category of oils and fats owns, within others foods, an important source of exposure to polycyclic aromatic hydrocarbons (PAHs), a group of organic chemical contaminants, some of them with carcinogenic activity. This study aimed at evaluating cold-pressed vegetable oils in relation to the PAHs occurrence, as well as the quality and identity parameters. Forty samples being ten of each type (coconut oil, safflower oil, evening primrose oil and flaxseed oil) of distinct brands, which were acquired in different markets from São Paulo, were evaluated. Fatty acids profile, acid value, peroxide value, p-anisidine value, total oxidation value (totox) and PAHs (benzo(a)anthracene, chrysene, benzo(b)fluoranthene and benzo(a)pyrene) were analyzed. As for FA, fourteen oils (35 per cent ) showed different fatty acids profiles according to the ones on their labels, including one of coconut oil, four of safflower oils and nine of evening primrose oils. The acid values were unsuitable towards the legislation to three flaxseed oils (7.5 per cent ). As for peroxide values, four of the oils (10 per cent ) were above the legislation limit, including two of flaxseed oils and two of evening primrose ones. The p-anisidine values ranged from <LOQ to 12.98, being the smallest value found in the coconut oils samples and the biggest ones in an evening primrose oil, which featured an altered odor. In the totox analysis, 37,5% of the samples presented values above the normal pattern according to literature, mailly the safflower and theevening primrose oils. Regarding the PAHs, at least one of the analyzed hydrocarbons was detected in 97,5% of the samples; three of the primrose samples (7,5%) had levels above those allowed by the European Community for BaP. According to the sum of 4 PAHs, eight oils (20%) were in disagreement: two of safflower oils, four of evening primrose oils and two of flaxseed oils. This study exposes problems related to identity and quality parameters, contamination of vegetable oils marketed as cold-pressed. It also aims at reinforcing the importance of a continuous monitoring os these products.

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