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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.
101

Intérêt des polymères à empreintes moléculaires pour la préparation d'échantillons par extraction solide-liquide. <br />Applications aux triterpènes dans les plantes et aux dopants dans les urines.

Claude, Bérengère 27 March 2007 (has links) (PDF)
Ce mémoire reporte les études menées sur des polymères à empreintes moléculaires (MIP) en extraction solide-liquide (SPE). L'influence de différents facteurs (nature des interactions polymère-analyte, composition de la matrice de l'échantillon, polarité des solvants d'extraction) sur la sélectivité et la capacité des MIPs est étudiée. <br />La première application révèle l'influence des liaisons hydrogène lors de l'extraction d'un échantillon organique sur un MIP préparé à partir d'acide méthacrylique (MAA). Des expériences de réactivité croisée réalisées sur des molécules analogues à la molécule empreinte (triterpène) montrent l'impact de la nature et de la position des groupes fonctionnels sur la spécificité de reconnaissance des analytes par le MIP. La capacité d'une cartouche SPE est évaluée à partir d'une solution standard puis d'un extrait végétal avec des solvants de lavage adaptés à la matrice. <br />Les interactions polymère-analyte sont ensuite étudiées dans une matrice aqueuse saline. Deux MIPs respectivement préparés à partir de MAA et de MAA-styrène, avec le clomiphène comme molécule empreinte, sont caractérisés par les isothermes de Freundlich puis appliqués à la préconcentration du tamoxifène, molécule hydrophobe et basique contenue dans des urines hydrolysées et dopées. Les liaisons hydrogène, ioniques et hydrophobes intervenant dans la rétention des analytes sont étudiées par des équilibres d'adsorption et par SPE. La percolation de l'urine sur un support hydrophobe en préalable de la SPE-MIP, ou directement sur un MIP à caractère hydrophobe renforcé (MAA-styrène) entraîne une augmentation des rendements d'extraction avec un nombre d'étapes de lavage réduit.
102

Societas Unius Personae : Is there a need for a new European company form?

Abosh, Shilan January 2015 (has links)
In 2008, the European Commission proposed a regulation for a new European private company, called the Societas Privata Europeaea. This proposal did not get unanimous approval and was therefore withdrawn after five years of attempt to find a compromise. In 2014, the European Commission proposed a directive on single-member private limited liability companies, called the Societas Unius Personae. The aims of the new proposal have a few similarities as the European private company, as will be mentioned in the introduction. However, the proposed directive introduces a few changes, which the European Commission hopes will make this proposal successful. The purpose with this thesis is mainly to examine whether there is a need of a new European company form on the market today. The conclusion is taken by examining who would benefit the most with this company form. This thesis contains an explanation of the proposed directive, a comparison between this new company form and the corresponding Swedish company, as well as opinions on this directive. In the end there is a discussion regarding this subject and lastly my conclusions. The result has shown that there are still great amount of uncertainties that are in need of further discussion in order for this proposal to eventually pass unanimous consent. My conclusions are that there is not an urgent need of a new European company form on the market right now. However, it is a work in progress, and I believe a European company form like this one is a good way towards the aim of uniting the Member States of the European Union.
103

Biodegradation of Bisphenol-A and 17B-Estradiol in Soil Mesocosms Under Alternating Aerobic/Anoxic/Anaerobic Conditions

Kim, Won-Seok 01 January 2011 (has links)
Soil-aquifer treatment (SAT) has been proposed as a method for reusing treated municipal wastewater. SAT is characterized by alternating cycles of aerobic and anaerobic conditions in the subsurface, in response to alternating cycles of flooding and drainage of a surface impoundment. It is not yet known how these alternating redox conditions affect the removal of potentially harmful endocrine-disrupting compounds (EDCs) from treated effluent. The overall objective of my doctoral research is to determine the fate of EDCs in alternating aerobic/anoxic/anaerobic conditions under simulated SAT conditions. To assess the fate of EDCs in simulated SAT conditions, I first had to develop appropriate analytical methods. Prior researchers have developed sophisticated analytical methods for measuring low concentrations of EDCs in water. However, it is not inherently clear which of these methods is preferable for analysis of any particular set of environmental samples. Therefore, in order to compare the analytical methods, solid-phase extraction (SPE) and solid-phase micro-extraction (SPME) were compared for the analysis of two EDCs, bisphenol-A (BPA) and 17B-estradiol (E2), in water samples of water. Following extraction by SPE or SPME, the target EDCs were derivatized (silylated) and then analyzed by gas chromatography (GC) with mass spectrometry (MS). Also, the performance of two candidate derivatization agents, N,O-bis-(trimethylsiyl) trifluoroacetamide (BSTFA), N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA), was compared. SPME is more convenient, is less labor-intensive, and allows for analysis of smaller sample volumes, but it is expensive because fibers need frequent replacement, and the range of linearity was limited. SPE has a lower material cost and allows for the analysis of a broader range of concentrations, but it is more labor-intensive and large sample volumes may be required. Therefore, the selection of which method is "best" depends upon the constraints (time, money, sample volume, acceptable detection limit) associated with any particular set of samples. The two derivatization agents performed equally when used in conjunction with SPE, but MSFTA yielded higher peak areas for headspace (on-fiber) derivatization during SPME. To investigate how alternating redox conditions of SAT may affect the removal of harmful EDCs, a simulated SAT systems were constructed in 4-L reactors with 500 g of sediment (collected from a wetland) and 3 L of treated effluent from a municipal wastewater treatment plant; then BPA and E2 were spiked into reactors, two common EDCs often found in treated wastewater. Redox conditions in the mesocosms were controlled by switching the air between air (to induce aerobic conditions) and nitrogen (to induce anaerobic conditions); the length of the anoxic/anaerobic cycles was varied to determine how this affects biodegradation of the target EDCs. The mesocosm environment was supplemented with either nitrate or sulfate to serve as potential electron acceptors during the anoxic/anaerobic cycles. In addition to monitoring the concentrations of the target EDCs in the mesocosms over time, I also monitored the concentration of dissolved oxygen in the water; the redox potential; the concentrations of nitrate, nitrite, and sulfate; and the concentration of bacteria in the water (estimated via flow cytometry). BPA was biodegraded only during aerobic cycles, but E2 was biodegraded during both aerobic and anoxic/anaerobic cycles. Whenever the redox conditions in the system were switched, there was a temporary drop in the bacterial population, followed by a recovery of the population. When redox conditions were switched from anoxic/anaerobic to aerobic, biodegradation of the target EDCs commenced after a lag period during which no biodegradation was observed. The lag time for biodegradation in the aerobic cycle was longer when the anaerobic cycles were longer in duration. More biodegradation of E2 was observed under anoxic conditions than under anaerobic conditions. SPE and SPME methods that included derivatization agent are useful method for detection and quantification of EDCs in water. I concluded that SAT is a viable technology to produce potable water from treated WWTP effluent, but the optimal length of flooding and drying cycles of SAT required removing the targeted contaminants during infiltration through the vadose zone.
104

Development and evaluation of sample preparation procedure for human plasma samples in LC/MS-based metabolomics

Kölfeldt, Niklas January 2015 (has links)
The aim of this master thesis project was to develop methods for sample preparation and analysis by LC-MS suitable for global metabolomics of human plasma samples. In this thesis six different methods was tested, based on precipitation, solid phase extraction (SPE), and ultrafiltration. The methods differ in their mechanisms of action, but the end goal is the same, to remove the proteins and other high molecular weight compounds from the samples and to retain as many metabolites as possible in a reproducible manner. The LC-MS analysis were performed on a C18 and a HILIC type column using electrospray ionization (ESI) with both positive and negative ionization to cover as much of the metabolome as possible. The MarkerLynx software was then used to extract features from the chromatograms. The coefficient of variation (CV) was calculated and the features with CV &gt; 30 % were removed. The features were then used to compare the methods with each other in order to see whether any of the methods yielded the same capture of features. The largest amount of features was detected for precipitation with MeOH when using a C18 type column. For HILIC type columns precipitation with MeOH with a small addition of H3PO4 resulted in most unique features detected. The ionization mode was found to be less important, compared whit the choice of column, but more features was detected using positive mode than negative mode.
105

Design, construction and testing of a high-vacuum anneal chamber for in-situ crystallisation of silicon thin-film solar cells

Weber, J??rgen Wolfgang, Photovoltaic & Renewable Engergy Engineering, UNSW January 2006 (has links)
Thin-film solar cells on glass substrates are likely to have a bright future due to the potentially low costs and the short energy payback times. Polycrystalline silicon (poly-Si, grain size &gt 1 pm) has the advantage of being non-toxic, abundant, and long-term stable. Glass as a substrate, however, limits the processing temperatures to ~600??C for longer process steps. Films with large grain size can be achieved by solid phase crystallisation (SPC), and especially by solid phase epitaxy (SPE) on seed layers, using amorphous silicon deposited at low temperatures as a precursor film. With SPC and SPE, the amorphous silicon film is typically crystallised at ~600??C over hours. During this anneal at atmospheric pressure -depending on the properties of the amorphous silicon film- ambient gas can percolate the film and can negatively affect the crystallisation. In this work, a high-vacuum anneal chamber was designed and built to allow the in-situ crystallisation of amorphous silicon films deposited on glass in a PECVD cluster tool. An important aspect of the design was the comfortable and safe operation of the vacuum anneal chamber to enable unattended operation. This was realised by means of a state-of-the-art, programmable temperature controller and a control circuit design that incorporates various safety interlocks. The chamber interior was optimised such that a temperature uniformity of 2-3K across the sample area was achieved. The chamber was calibrated and tested, and SPC and SPE samples were successfully crystallised. In initial SPC crystallisation experiments with solar cell structures, after post-deposition treatments, a 1 -sun open-circuit voltage of 465 mV was obtained, similar to furnace-annealed samples. In initial experiments with SPE solar cell structures, difficulties regarding the characterisation of the unmetallised solar cells with the quasi-steady-state open-circuit voltage method (QSSVOC) were encountered after post-deposition hydrogen treatment. A possible explanation for these difficulties is the contact formation with the metal probes. Furthermore, limiting factors of the QSSVOC method for the characterisation of unmetallised cells with high contact resistance values were investigated and, additionally, the accuracyof the QSSVOC setup was improved in the low light intensity range.
106

STL on Limited Local Memory (LLM) Multi-core Processors

January 2012 (has links)
abstract: Limited Local Memory (LLM) multicore architectures are promising powerefficient architectures will scalable memory hierarchy. In LLM multicores, each core can access only a small local memory. Accesses to a large shared global memory can only be made explicitly through Direct Memory Access (DMA) operations. Standard Template Library (STL) is a powerful programming tool and is widely used for software development. STLs provide dynamic data structures, algorithms, and iterators for vector, deque (double-ended queue), list, map (red-black tree), etc. Since the size of the local memory is limited in the cores of the LLM architecture, and data transfer is not automatically supported by hardware cache or OS, the usage of current STL implementation on LLM multicores is limited. Specifically, there is a hard limitation on the amount of data they can handle. In this article, we propose and implement a framework which manages the STL container classes on the local memory of LLM multicore architecture. Our proposal removes the data size limitation of the STL, and therefore improves the programmability on LLM multicore architectures with little change to the original program. Our implementation results in only about 12%-17% increase in static library code size and reasonable runtime overheads. / Dissertation/Thesis / M.S. Computer Science 2012
107

Determinação de anti-inflamatórios em efluente urbano na região de Porto Alegre-RS por SPE, derivatização e GC-MS

Becker, Raquel Wielens January 2012 (has links)
Neste trabalho estudou-se o desenvolvimento de metodologia analitica para a determinação e quantificação de sete anti-inflamatórios não esteroides, amplamente consumidos para tratamento humano, além da cafeína, determinada como marcador antropogênico, em amostras aquosas ambientais. Os analitos estudados foram acetaminofeno (AC), ácido salicílico (AS), cafeína (CA), cetoprofeno (CE), diclofenaco (DC), dipirona (DP), ibuprofeno (IB) e naproxeno (NA) . Como padrão internos, foi utilizado o lindano (LI). A determinação destes analitos foi realizada utilizando-se cromatografia a gás acoplada à espectrometria de massas (GC-MS) utilizando MSTFA/Imidazol como derivatizante. As condições para a reação de derivatização foram otimizadas utilizando o planejamento Doehlert. O procedimento de pré-concentração utilizado foi a extração em fase sólida (SPE), tendo como sorvente um sistema de fase polimérica reversa. O procedimento de SPE foi baseado em trabalhos publicados na literatura, com metanol e água (ajustada a pH 3,0) para o condicionamento e eluição com acetonitrila. Os parâmetros de desempenho do método, como recuperação, linearidade, limite de detecção, limite de quantificação, repetitividade e reprodutibilidade foram avaliados de acordo com as normas estabelecidas pela ANVISA e INMETRO. Os limites de detecção ficaram entre 1,09 e 1079,14 ng L-1 e os de quantificaçõ entre 3,63 e 3597,12 ng L-1. Após as definições em relação ao método, amostras de água do Arroio Dilúvio (em Porto Alegre – RS) e de uma Estação Piloto de tratamento de efluente pertencente ao Instituto de Pesquisas Hidráulicas (IPH/UFRGS) , foram analisadas para avaliar a presença destes analitos. As amostras da ETE-piloto do IPH, foram coletadas nos meses de janeiro e fevereiro e as amostras do Arroio Dilúvio também foram coletadas no mesmo período. Considerando as amostras reais analisadas em algumas foram detectados e em outras quantificados os antiinflamatórios estudados. Nas amostras que estes compostos foram quantificados, a faixa de concentração variou entre 0,09 e 23,16 μg L-1. / In this work the development of an analytic methodology was studied to determine and quantify seven non-steroidal anti-inflammatory drugs, widely used in human treatment, and caffeine considered an anthropogenic marker. The compounds studied were acetaminophen (AC), salicylic acid (AS), caffeine (CA), ketoprofen (CE), diclofenac (DC), dipyrone (DP), ibuprofen (IB), naproxen (NA) and lindane (LI) as internal standard. The determination of these compounds was performed using gas chromatography coupled to mass spectrometry (GC-MS) with derivatization of the target analytes using MSTFA/Imidazole. The derivatization conditions were optimized with Doehlert design. Solid phase extraction (SPE) with a polymeric reversed solid phase was used as a pre-concentration system. The SPE procedure conditions were based previously established data in the literature, using methanol and water (adjusted to pH 3.0) for the conditioning step and acetonitrile for the elution step The performance parameters, such recovery, linearity, detection limit, quantification limit, repeatability and reproducibility were evaluated according to ANVISA and INMETRO determinations. The detection limits was in the range of 1,09 and 1079,14 ng L -1 and the quantification limits 3,63 and 3597,12 gn L-1. After method establishment, samples from a piloto sewage treatment plant and river water, both in Porto Alegre-RS, were analysed. The samples were collected in January and February 2012, both in the pilot plant and in the river water. In some real samples the antiinflammatories were detected and in others was possible quantify. In the samples were the analytes were quantified, the concentration range was 0,09 to 23,16 μg L-1.
108

Otimização de amostradores passivos para a determinação de pesticidas em águas utilizando SPE e GC-MS

Silva, Maria Andréa da January 2012 (has links)
Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-03-27T15:24:14Z No. of bitstreams: 1 Tese de Maria Andréa da Silva.pdf: 2665297 bytes, checksum: 5d7613a0f2ca73967ba58859bd84a7f5 (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-04-15T14:01:43Z (GMT) No. of bitstreams: 1 Tese de Maria Andréa da Silva.pdf: 2665297 bytes, checksum: 5d7613a0f2ca73967ba58859bd84a7f5 (MD5) / Made available in DSpace on 2013-04-15T14:01:43Z (GMT). No. of bitstreams: 1 Tese de Maria Andréa da Silva.pdf: 2665297 bytes, checksum: 5d7613a0f2ca73967ba58859bd84a7f5 (MD5) Previous issue date: 2012 / CAPES / Neste trabalho foram usados amostradores passivos POCIS e Chemcatcher com a técnica de Extração em Fase Sólida SPE e a Cromatografia Gasosa acoplada à Espectrometria de Massas, GC/MS. O objetivo geral do trabalho foi desenvolver uma metodologia para os amostradores passivos POCIS e Chemcatcher para a análise de agrotóxicos em água superficial e os objetivos específicos: estudar o desempenho dos amostradores passivos através de desenvolvimento de metodologia SPE e GC/MS, calibrar em laboratório, determinando as taxas de amostragem e implantar os amostradores na região do Vale do São Francisco, em Petrolina, Pernambuco. O sorvente usado na SPE foi à base de sílica modificada (C18) e os solventes foram metanol e diclorometano. A validação do método foi feita para disco e cartucho, onde, o LD para disco variou de 0,0080 a 0,096 μg L-1 e para cartucho 0,0070 a 0,43 μg L-1, o LQ de 0,026 a 0,32 μg L-1 e 0,024 a 1,4 μg L-1, respectivamente. Os percentuais de recuperação para o disco variaram de 70,0 a 119,9 para disco e 70,2 a 119,7 para cartucho. Os desvios-padrões para o disco variaram de 2,86 a 19,9 e para cartucho 1,89 a 19,8. A repetitividade com 95% de confiança para disco variou de 0,0070 a 0,089 e 0,0070 a 0,41 para cartucho. As taxas de amostragem para os dispositivos POCIS e Chemcatcher variaram, respectivamente: para 1 dia: sem membrana, 0,105 a 0,693 L dia-1 e 0,100 a 0,757 L dia-1; com membrana PES < 0,0080 a 0,069 L dia-1 e <0,0080 a 0,050 L dia-1; com malha de nylon 0,103 a 0,333 L dia-1 e 0,093 a 0,33 L dia-1. Para 3 dias com renovação de água: com membrana PES < 0,011 a 0,083 L dia-1 e < 0,011 a 0,042 Ldia-1; com malha de nylon 0,077 a 0,80 L dia-1 e 0,074 a 0,95 L dia-1. Durante três dias sem renovação de água: com malha de nylon 0,067 a 0,28 L dia-1 e 0,064 a 0,31 L dia-1. Taxas de amostragem teóricas foram calculadas em função dos coeficientes de difusão dos pesticidas em água e do desenho e configuração dos dois modelos de amostradores passivos. As taxas de amostragem para o POCIS e Chemcatcher variaram respectivamente de 0,11 a 0,23 L dia-1 e 0,077 a 0,16 L dia-1. Considerando-se um ambiente aquático com baixa contaminação (ao nível do LQ do método) o tempo de exposição dos amostradores para captar os pesticidas pode variar, a depender do composto, de 3 a 9 dias para o POCIS e de 4 a 10 dias para o Chemcatcher. O desempenho dos dois modelos pode ser considerado semelhante e seu uso com a técnica SPE e GC/MS é uma alternativa para a metodologia de determinação de pesticidas em água, uma vez que o procedimento é simples, rápido e econômico. / Salvador
109

Determinação de desreguladores endocrinos na água e no sedimentos do açude Santo Anastácio na cidade de Fortaleza/Ce / Determination of endocrine disruptors in water and sediment from Santo Anastácio weir in the city Fortaleza/Ce

Silva, Maria Nataniela da January 2016 (has links)
SILVA, Maria Nataniela da. Determinação de desreguladores endocrinos na água e no sedimentos do açude Santo Anastácio na cidade de Fortaleza/Ce. 2016. 96 f. Dissertação (Mestrado em química)- Universidade Federal do Ceará, Fortaleza-CE, 2016. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-07-28T18:06:46Z No. of bitstreams: 1 2016_dis_mnsilva.pdf: 3478037 bytes, checksum: 1050688c4f7e4c965ade54f50fe76a97 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-08-02T14:30:05Z (GMT) No. of bitstreams: 1 2016_dis_mnsilva.pdf: 3478037 bytes, checksum: 1050688c4f7e4c965ade54f50fe76a97 (MD5) / Made available in DSpace on 2016-08-02T14:30:06Z (GMT). No. of bitstreams: 1 2016_dis_mnsilva.pdf: 3478037 bytes, checksum: 1050688c4f7e4c965ade54f50fe76a97 (MD5) Previous issue date: 2016 / Natural and synthetic estrogens are naturally excreted by humans and some vertebrates. These emerging contaminants classified as endocrine disruptors (EDs) present, even in small quantities, in water and sediment are able to affect the endocrine system and the stages of growth and reproduction of aquatic organisms and humans. In this context, this study aimed to perform a physical-chemical and microbiological characterization of reservoir water from Santo Anastácio, located in Ceará, Brazil, and the develop and validate an analytical method using High-performance liquid chromatography with detector diode array (HPLC-DAD) for the determination of caffeine (CAF) and estrone hormones, 17β-estradiol, estriol (natural) and 17α-ethinylestradiol (synthetic) for water and sediment phase of reservoir water studied. The physicochemical parameters evaluated were phosphorus, chlorophyll A, pheophytin, nitrogen, chloride, sulfide, hardness, calcium, magnesium, pH, alkalinity, turbidity and total and dissolved solids. Microbiological characterization evaluated the presence of total and fecal coliforms. For the determination of EDs by HPLC-DAD was used to extract solid phase techniques (SPE) for water sample and QuEChERS for the sediment sample. The results of physicochemical analyzes indicated above the allowed values by CONAMA 357/05 for class 2, only to phosphorus and sulfide. Microbiological characterization indicated the presence of coliforms far above the values stipulated by CONAMA. In determining the DEs concentrations from 0.54 to 0.93 μg L-1 were detected caffeine in water, and 0.76 to 4.94 mg kg-1 17β estradiol and estriol in the sediment. Therefore, the water reservoir is unsuitable for direct consumption and recreation within the law. The validated analytical method was efficient for the determination of analytes can be used for routine analysis since there is no legislation to caffeine and EDs. / Estrógenos naturais e sintéticos são naturalmente excretados por seres humanos e alguns vertebrados. Estes contaminantes emergentes classificados como desreguladores endócrinos (DEs) presentes, mesmo em pequenas quantidades, na água e no sedimento são capazes de afetar o sistema endócrino e as fases de crescimento e reprodução de organismos aquáticos e humanos. Nesse contexto, este trabalho teve como objetivos efetuar uma caracterização físico-química e microbiológica da água do açude Santo Anastácio, localizado no Ceará, Brazil, além de desenvolver e validar um método analítico empregando a cromatografia líquida de alta eficiência com detector de arranjos de diodos (HPLC-DAD) para determinação da cafeína e dos hormônios estrona, 17β-estradiol, estriol (naturais) e 17α-etinilestradiol (sintético) na água e no sedimento do açude mencionado. Os parâmetros físico-químicos avaliados foram fósforo, clorofila A, feofitina, nitrogênio, cloreto, sulfeto, dureza, cálcio, magnésio, pH, alcalinidade, turbidez e sólidos totais e dissolvidos. A caracterização microbiológica avaliou a presença de coliformes totais e termotolerantes. Para a determinação dos DEs por HPLC-DAD utilizou-se as técnicas de extração em fase sólida (SPE) para a amostra de água e QuEChERS para a amostra de sedimento. Os resultados das análises físico-químicas indicaram valores acima do permitido pelo CONAMA 357/05, para classe 2, apenas para fósforo e sulfeto. A caracterização microbiológica indicou a presença de coliformes muito acima dos valores estipulados pelo CONAMA. Na determinação dos DEs foram detectados as concentrações de 0,54 a 0,93 μg L-1 de cafeína na água, e, 0,76 a 4,94 mg kg-1 do 17β estradiol e estriol no sedimento. Diante disso, a água do açude encontra-se inadequada para consumo direto e recreação dentro da legislação vigente. O método analítico validado mostrou-se eficiente para determinação dos analitos podendo ser utilizado para análises de rotina uma vez que não existe legislação para a cafeína e os DEs.
110

Contaminação de agrotóxicos na água para consumo humano no RS : avaliação de riscos, desenvolvimento e validação de método empregando SPE e LC-MS/MS

Zini, Luciano Barros January 2016 (has links)
Os agrotóxicos, quando presentes na água, são definidos como micropoluentes: mesmo em baixas concentrações, conferem à água características de toxicidade. Aponta-se o RS como o quarto estado do Brasil com maior volume de vendas anuais de agrotóxicos, chegando a mais de 50 mil toneladas por ano. Desde 2014 está em vigência no território gaúcho uma portaria estadual que acrescenta a exigência de 46 parâmetros de agrotóxicos no padrão de potabilidade da água, além dos 27 já exigidos pela portaria nacional. Neste trabalho, 89 pesticidas foram avaliados conforme três métodos teóricos de predição de risco de contaminação em mananciais subterrâneos e superficiais: índice Ground Ubiquity Score (GUS), método Screening da USEPA e método de GOSS, baseados nas propriedades físico-químicas dos pesticidas. Nos anos de 2015 e 2016, foram realizadas 143 coletas de água para consumo humano em 45 municípios da bacia hidrográfica do Alto Jacuí (G-50), a que possui a maior taxa de aplicação de agrotóxicos do estado, para análises de vigilância através de laboratório contratado, envolvendo os 89 pesticidas presentes na portaria nacional e estadual. Em paralelo, 183 pesticidas presentes em uma solução-padrão foram empregados no desenvolvimento de um novo método de análise multiresíduos, com etapas de pré-tratamento por filtração seguidas por extração em fase sólida e LC-MS/MS, aplicada para os três maiores municípios da G-50 (Carazinho, Soledade e Cruz Alta) em amostras de água bruta e tratada, durante quatro períodos de aplicação de agrotóxicos dos principais cultivos agrícolas da região. Dos pesticidas mencionados nas portarias nacional e estadual, 12 foram classificados com o maior risco de contaminação tanto em água superficial e subterrânea de acordo com os três métodos teóricos empregadas. Nas análises de vigilância foi detectado permetrina em Carazinho e alaclor em Espumoso. No método desenvolvido, 75 pesticidas foram validados de acordo com os critérios propostos e atingiram limites de detecção (LD) e limites de quantificação (LQ) que variaram de 10 a 300 ng L-1. Na aplicação do método nas coletas dos três municípios da G-50 não houve detecção de nenhum pesticida. / Agrochemicals, when present in water, are defined as micropollutants, thus giving the water toxic characteristics, even at low concentrations. The Rio Grande do Sul state in Brazil was found to rank fourth in annual agrochemical sales in the country, surpassing 50 thousand tons per year. A state regulation in effect in the RS state since 2014 requires the inclusion of 46 new agrochemical parameters concerning the standards for potable drinking water, in addition to 27 existing parameters mandated by national ordinance. Seventy-five pesticides were evaluated based on three theoretical methodologies of contamination risk prediction in underground and surface water sources, by measuring the physicochemical properties of pesticides: GUS index, USEPA screening method and Goss method. In 2015 and 2016, 143 water samples were collected from sources of potable water in 45 municipalities located in the Alto Jacuí river basin, a region which has the highest pesticide application rate in the RS state. A private laboratory analyzed samples from 89 pesticides present in the national and state regulation. Paralely, 183 pesticides were evaluated by a new multi-residue analysis method. Filtration was conducted in the pre-treatment steps, followed by a solid phase extraction liquid chromatography coupled with mass spectrometry analysis (SPE-LC-MS/MS) of raw and treated water samples from the three largest G-50 municipalities (Carazinho, Soledade and Cruz Alta), during the four pesticide application periods of the main crops cultivated in the region. Twelve pesticides were classified as of high risk in terms of contamination for both surface and groundwater, in accordance with the three theoretical methodologies implemented. During analysis of the surveillance data collected, the pesticides permethrin and alachlor were found in Carazinho and Espumoso, respectively. Through the methodology developed, 75 pesticides were evaluated according to the criteria proposed, reaching lower detection limit (LD) and quantification limit (LQ) ranging from 10 to 300 ng L-1, respectively. During the implementation of the methodology for sample collections in the three G-50 municipalities, no pesticides were detected.

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