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1
Blyden, E. R. « Molecular genetics of triazine resistance in Senecio vulgaris L ». Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383076.
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PEREZ, YAFA. « Toxicologie et ecotoxicologie des triazines utilisees comme herbicides et particulierement des chlorotriazines ». Strasbourg 1, 1987. http://www.theses.fr/1987STR10719.
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3
Vencill, William K. « Triazine resistance in Chenopodium album and Amaranthus hybridus in Virginia ». Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/94485.
Texte intégralRésumé :
Studies were conducted to determine the distribution of s-triazine resistant biotypes of common lambsquarters (Chenopodium album L.) and smooth pigweed (Amaranthus hybridus L.) in Virginia. Collections of seed were made from suspected triazine-resistant biotypes of common lambsquarters and smooth pigweed from counties in Virginia which had reported having triazine resistance problems. Triazine resistance was confirmed by measuring chlorophyll fluorescence in the presence of atrazine. For further confirmation of triazine resistance in collected common lambsquarters and smooth pigweed biotypes, greenhouse testing of whole plants and a sinking leaf disc assay were performed. Cross-resistance to another s-triazine, as-triazine, and substituted urea herbicide was also determined for s-triazine-resistant biotypes. These studies have shown triazine- resistant smooth pigweed to be present in 19 counties and common lambsquarters to be present in 8 counties in Virginia. s-Triazine resistant biotypes were found to be resistant to another s-triazine and as-triazine herbicide, but were susceptible to the substituted urea herbicide. Additional studies were initiated to determine the effects of different temperature regimes on triazine-resistant and -susceptible biotypes of common lambsquarters and smooth pigweed from different geographical locations. These studies were conducted at the North Carolina State University Phytotron facility in controlled environment growth chambers. Triazine-resistant common lambsquarters biotypes from Virginia, Maryland, and Switzerland as well as a smooth pigweed biotype from Virginia were examined. Triazine-susceptible biotypes of common lambsquarters and smooth pigweed were included as controls. Shoot height, weight, chlorophyll a and b content, and whole leaf fatty acid content of common lambsquarters and smooth pigweed were determined at 18°/14° C, 26°/22° C, and 36°/26° C. Measurements of shoot height were made at 30 and 63 days after planting. The shoot weight, chlorophyll a and b content, and fatty acid content was determined from plants harvested at 63 days after planting. These data indicate common lambsquarters biotypes from different geographical regions exhibited a differential response to temperature. There was no difference between triazine-resistant and -susceptible biotypes in response to temperature. Differences were detected between triazine-resistant smooth pigweed biotypes which indicated that the susceptible biotypes were more vigorous as indicated by shoot height and weight at lower temperatures than triazine-resistant biotypes of smooth pigweed.M.S.
4
Biagianti, Sylvie. « Contribution à l'étude du foie de juvéniles de muges (Téléostéens, Mugilides), contaminés expérimentalement par l'atrazine (s-triazine herbicide) : approche ultrastructurale et métabolique : intérêt en écotoxicologie ». Perpignan, 1990. http://www.theses.fr/1990PERP0084.
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Andrade, Felipe Nascimento. « Síntese e emprego de polímeros molecularmente impressos em técnicas miniaturizadas acopladas a cromatografia liquida para análises de triazinas e sulfoniluréias em amostras de milho ». Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-09032016-134923/.
Texte intégralRésumé :
As triazinas e sulfoniluréias tem sido muito empregadas, devido ao crescente aumento na produção agrícola e aplicação de herbicidas nas lavouras, podendo causar sérios riscos à saúde humana e ao meio ambiente. Uma problemática é a baixa concentração que estes analitos são encontrados, tornando-se necessário o emprego do preparo da amostra para a sua determinação. Com isso, a busca por técnicas de preparo de amostras miniaturizadas, simples, de baixo custo, com menores riscos de contaminações ambientais e baixo consome de solventes, tem grande predominância. Dentre as microtécnicas de preparo de amostra podemos destacar a microextração em dispositivos preenchidos com sorventes (MEPS, do inglês, Microextraction by Packed Sorbent) e a microextração adsortiva em barra (BAμE, do inglês, Bar Adsorptive Microextraction). Outro aspecto desejado no preparo de amostras é a obtenção de uma maior seletividade quanto ao sorvente empregado, quando comparado àqueles convencionais como, por exemplo, sílica modificada (ex. C18), resinas Amberlite XAD, entre outros. Nesse âmbito, o presente trabalho apresenta a síntese de dois polímeros impressos molecularmente (MIP, do inglês, Molecularly Imprinted Polymers) e suas aplicações na adsorção seletiva de moléculas de triazinas e sulfoniluréias, com separação, identificação e quantificação feitas por LC-TOF-ESI e HPLC-DAD. A primeira metodologia desenvolvida foi a síntese dos polímeros impressos empregando o ácido metacrílico e o etileno glicol dimetacrilato. Após a síntese, os polímeros foram caracterizados através da espectroscopia de infravermelho e microscopia eletrônica de varredura. O coeficiente de seletividade para o MIP foi comparado com o coeficiente de seletividade do polímero não impresso (NIP, do inglês, non imprinted polymers) para misturas binárias de atrazina/picloram, atrazina/propanil, bensulfuron/betazon e bensulfuron/prometon onde os valores dos coeficientes de seletividade relativa (k\') obtidos foram de 17,2, 3,2, 10,6 e 8,5. A seguir, foram desenvolvidos dois métodos empregando MEPS para as triazinas e sulfoniluréias, respectivamente. Os métodos validados baseando-se nas recomendações da Agência Nacional de Vigilância Sanitária (ANVISA) e com diretrizes da Comunidade Europeia, apresentaram linearidade, seletividade, precisão, exatidão e recuperação adequadas para as triazinas e sulfoniuréias. Os limites de quantificação obtidos foram da ordem de 5,0-10,0 μg kg-1 para as triazinas e 2,5 μg kg-1 para as sulfoniluréias. Ainda com propósito de determinar esses herbicidas em milho, dois novos métodos de preparo de amostra foram desenvolvidos, empregando a BAμE. A BAμE, foi desenvolvida recentemente e combinada com os polímeros molecularmente impressos, avaliou-se sua determinação para as triazinas e sulfoniluréias. As variáveis da técnica BAμE foram otimizadas e, em seguida, validadas. Os limites de quantificação obtidos foram da ordem de 0,7 μg kg-1 para as triazinas e 0,4 μg kg-1 para as sulfoniluréias. Os métodos propostos foram aplicados com sucesso para determinação de triazinas em diferentes amostras de milho verde, com valores de recuperação satisfatórios na faixa de 80,0 -120,9%.Triazines and sulfonylureas have been much used due to the growing in agricultural production and application of herbicides on crops, which may cause serious risks to human health and the environment. One problem is the low concentration found of these analytes, making it necessary the use of the sample preparation. Thus, the search for miniaturized sample preparation such as techniques simple, low cost, with less risk of environmental contamination and low solvent consumes has great predominance. Among the sample preparation microtechnology we can highlight the microextraction by packed sorbent (MEPS) and bar adsorptive microextraction (BA?E). Another desired aspect for sample preparation is to obtain a higher selectivity concerning the sorbent employed as compared to their conventional format; for example, modified silica (ex. 18), Amberlite XAD resins, and others. In this context, this paper presents the synthesis of two molecularly imprinted polymers (MIPs) and their applications in the selective adsorption of triazines and sulfonylureas molecules being the separation, identification and quantification steps made by LC-TOF-ESI and HPLC-DAD. The first step developed was the synthesis of imprinted polymers using methacrylic acid and ethylene glycol dimethacrylate. After synthesizing, the polymers were characterized by infrared spectroscopy and scanning electron microscopy. The MIP selectivity coefficient was compared with the NIP (non imprinted polymer) selectivity coefficient employing binary mixtures of atrazine / picloram, atrazine / propanil, bensulfuron / betazon and bensulfuron / prometon where the values of relative selectivity coefficients (k \') obtained were 17.2, 3.2, 10.6 and 8.5. Next, we developed two methods for MEPS triazines and sulfonylureas, respectively. The methods were validated based on the recommendations of the National Health Surveillance Agency (ANVISA) and the European Community directives, and presented linearity, selectivity, precision, accuracy and adequate recovery for the triazines and sulfoniuréias. The quantification limits were obtained in the range of 5.0-10.0 μg kg-1 for triazines and 2.5 μg kg-1 for sulfonylureas. Aiming determining these herbicides in corn samples, two new sample preparation methods were developed, using the BAμE. The recently developed BAμE, was combined with molecularly imprinted polymers to evaluate the determination to triazines and sulfonylureas. The BAμE variables were optimized and validated. The quantification limits were obtained in the range of 0.7 μg kg-1 for triazines and 0.4 μg kg-1 for sulfonylureas. The proposed methods were successfully applied for the determination of triazines in different samples of corn, with satisfactory recovery values in the range of 80.0 -120.9%.
6
Malotaux, Christophe. « Les Triazines-atrazine entre autres, présences dans l'environnement et dans l'eau ». Paris 5, 1992. http://www.theses.fr/1992PA05P242.
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Marchese, Luciana. « Sorção/dessorção e lixiviação do herbicida ametrina em solos canavieiros tratados com lodo de esgoto ». Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-03092007-154220/.
Texte intégralRésumé :
Vários estudos têm mostrado os benefícios da aplicação agronômica de lodo de esgoto sobre as propriedades físicas e químicas do solo. No entanto, poucos são aqueles que avaliam o impacto desta prática sobre o comportamento de pesticidas em solos tropicais. O principal objetivo deste estudo foi avaliar o efeito da adição de diferentes fontes de lodo (Ribeirão Preto, Franca e Jundiaí) na sorção / dessorção e lixiviação do herbicida ametrina em solos canavieiros do estado de São Paulo (Neossolo Quartzarênico Órtico Típico (RQ), Latossolo Vermelho Distrófico Típico (LVd), Argissolo Vermelho Eutroférrico Chernossólico (PV) e Latossolo Vermelho Distroférrico (LVdf). Cinco concentrações (de 4,4 a 79,8 mg i.a. L-1) do herbicida foram utilizadas para obter os valores dos coeficientes de sorção de Freündlich (Kf) e dos coeficientes aparentes de sorção médio e para a menor concentração (Kd ap médio e Kd ap [menor]), a qual corresponde à dose de campo recomendada. Para o teste de lixiviação, o método utilizado foi o de lixiviação em colunas de solo (diâmetro = 5 cm e comprimento = 30 cm), utilizando-se três repetições para cada tratamento, sobre as quais foi simulada chuva de 200 mm uniformemente distribuídas durante 48 h, após a aplicação da solução de 14Cametrina na dose de 3,0 kg i.a. ha-1. De forma geral, a sorção da ametrina variou de moderada à alta em todos os tratamentos (2,68 < Kd ap [menor] < 85,71 L kg-1). Solos argilosos com maior teor de matéria orgânica e argilas do tipo 2:1, como é o caso do PV, apresentaram muito maior potencial de sorção da ametrina; enquanto que solos arenosos com baixos teores de matéria orgânica, como foram os casos do LVd e RQ, apresentaram moderado potencial de sorção. A aplicação de lodos menos estabilizados, com biomassa e material orgânico menos recalcitrante e, portanto, com maiores valores de carbono orgânico total, carbono orgânico dissolvido e pH, como é o caso do lodo de Ribeirão Preto, tendeu a diminuir o potencial de sorção da ametrina. Já a adição de lodos mais recalcitrantes, como o de Jundiaí, tendeu a aumentar o potencial de sorção da ametrina, principalmente em solos arenosos devido a sua menor capacidade tampão. Nestes cenários, poderá ocorrer redução da eficácia agronômica ametrina, uma vez que haverá menos produto disponível na solução do solo. A ametrina apresentou baixo potencial de lixiviação (< 1% da quantidade aplicada) em todos os tratamentos, os quais não apresentaram diferenças entre si, sendo que a grande maioria do pesticida (> 95% da quantidade aplicada) ficou retida na camada de 0-10 cm de profundidade da coluna de solo. Isto implica dizer que a ametrina apresenta baixo potencial de contamina águas subterrâneas, mesmo em solos arenosos, como RQ (90% de areia)Several studies have shown the benefits of applying sewage sludge on the physical and chemical properties of the soils. However, just a few of them evaluates the impact of this practice on the behavior of pesticides in tropical soils. The main goal of this research was to evaluate the effects of applying different sources of sewage sludge (Ribeirão Preto, Franca e Jundiaí) on the sorption / desorption and leaching of ametryne in soils from São Paulo state (Brazil) cultivated with sugarcane (Neossolo Quartzarênico Órtico Típico (RQ), Latossolo Vermelho Distrófico Típico (LVd), Argissolo Vermelho Eutroférrico Chernossólico (PV) e Latossolo Vermelho Distroférrico (LVdf). Five concentrations (4.4 to 79.8 mg a.i. ha-1) of the herbicide were applied to the soil samples to attain the Freündlich sorption coefficients (Kf) and the apparent sorption coefficient for the lower concentration (Kd ap [menor]), which corresponded to the field application rate. For the leaching test the adopted method was the soil leaching columns (diameter = 5 cm and depth = 30 cm), in triplicates, over which a 200 mm rainfall evenly distributed during 48 h was simulated just after ametryne application at the rate of 3.0 kg a.i. ha-1. In general, ametryne sorption ranged from moderate to high in all treatments (2.68 < Kd ap [menor] < 85.71 L kg-1). Clay soils with higher organic matter and 2:1 clay contents, such as the PV, showed much higher sorption potential, whereas sand soils with low organic matter content, such as LVd and RQ, showed moderate sorption potential. The application of less stabilized sewage sludges, with less recalcitrant biomass and organic material and, therefore, with higher organic matter and dissolved organic carbon contents and pH values, such as the Ribeirão Preto, tends to decrease ametryne sorption potential. Otherwise, the addition of more recalcitrant sludges, such as the Jundiaí, tends to enhance its sorption potential, mainly in sand soils due to its lower buffer capacity. In those cases, the agronomic efficacy of ametryne may be reduced since there is lower concentration of the compound available in the soil solution. The ametryne presented low leaching potential in all treatments (< 1% of the applied amount), which were not different among themselves, and that its majority (> 95% of the applied amount) was found at 0 -10 cm soil depth in the column. It implies that ametryne has low potential to contaminate groundwater even in sandy soils, such as the RQ (90% sand)
8
Dupont, Stephane. « Bound (nonextractable) residues of triazine herbicides in soybean and canola plants ». Thesis, University of Ottawa (Canada), 1989. http://hdl.handle.net/10393/21091.
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Oketunde, Olukayode Felix. « The adsorptive behaviour of two triazine herbicides in three Nigerian soils ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq22372.pdf.
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Olson, B. M. « Spectroscopic study of interactions between s-triazine herbicides and humic substances ». Thesis, University of Aberdeen, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374630.
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Vilella, Kelly Adriana Ribeiro Tagliaferro 1987. « Análises de oxidação de triazínas com 'H IND.2 O IND.2' e catalisadas por metaloporfirinas via cromatografia gasosa/espectrometria de massas ». [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267731.
Texte intégralRésumé :
Orientador: Maria Aparecida Carvalho de MedeirosDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia
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Resumo: Os resíduos de herbicidas triazínicos são compostos com moderada toxicidade, altamente persistentes no ambiente, contaminando os mananciais e águas subterrâneas e são muito utilizados em várias culturas, inclusive da cana-de-açúcar. Os herbicidas atrazina e simazina foram oxidados com 'H IND.2O IND.2' na presença de catalisadores biomiméticos (metaloporfirinas de ferro e rutênio) e os produtos gerados na reação foram analisados via cromatografia gasosa (GC, do inglês gás chromatography) associada à espectrometria de massas (MS, do inglês mass spectrometry), buscando elucidar os subprodutos. As reações de oxidação dos herbicidas triazínicos e os subprodutos gerados foram monitoradas por espectrofotometria na região do ultra violeta e visível (UV-Vis) e cromatografia gasosa (GC), utilizando-se o detector de captura de elétrons (ECD, do inglês elétron capture detector). Os rendimentos das reações de oxidação das triazinas com 'H IND.2O IND.2' e catalisadas pelas metaloporfinas de ferro (Fe(FTTPCl)) e rutênio (Ru(OCTTPP)), variaram de acordo com as condições de reações catalíticas. Foi observado que houve degradação significativa dos analitos (94,70% para a atrazina e 92,60% para a simazina utilizando a (Fe(FTTPCl)) e; 94,38% para a atrazina e 67,19% para a simazina utilizando a (Ru(OCTTPP))) e também foi observado a transformação dos herbicidas nos subprodutos desetilatrazina (DEA) e o deisopropilatrazina (DIA). Os dados de monitoramento das reações catalíticas por UV-Vis revelaram as estabilidades dos catalisadores (Fe(FTTPCl)) e (Ru(OCTTPP)), nas condições oxidantes das reações. Os resultados obtidos com a cromatografia gasosa acoplada com a espectrometria de massas (GC-MS), utilizando a técnica de ionização por impacto de elétrons ¿ (EI, do inglês electron ionization), full scan, com o modo positivo (EI+), associado a este pico revelaram o pico do íon molecular (m/z= 215, associado ao herbicida atrazina [M]+ e os principais fragmentos (m/z): 200(associado ao íon [M ¿ CH3]+), 173 e 138; sendo que o espectro de massa obtido após a reação de oxidação revelou o desaparecimento do pico associado aos herbicidas e formação de novos picos, associados a fragmentos de subprodutos. Similarmente, a identificação da simazina foi obtida com o modo positivo (EI+), tendo sido revelado o pico do íon molecular (m/z= 201) e os principais fragmentos (m/z): 186, 173 e 138
Abstract: Waste triazine herbicides are compounds with moderate toxicity, highly persistent in the environment, contaminating water sources and groundwater are widely used in various cultures, including the cane sugar. The atrazine and simazine herbicides were oxidized with 'H IND.2O IND.2' in the presence of biomimetic catalysts (iron and ruthenium metalloporphyrins) and the products generated in the reaction were analyzed by gas chromatography (GC) associated with mass spectrometry (MS), to elucidate the by-products. The oxidation reaction of the triazine herbicide and by-products generated were monitored by spectrophotometry in the ultraviolet region and visible (UV-Vis) and gas chromatography (GC), using electron capture detector (ECD). Proceeds from the triazines oxidation reactions with 'H IND.2O IND.2' catalyzed by iron and metalloporphyrins (Fe (FTTPCl)) and ruthenium (Ru (OCTTPP)), varied according to the conditions of catalytic reactions. It was observed that there was significant degradation of the analytes (94.70% to 92.60% for atrazine and simazine using the (Fe(FTTPCl)) and; 94.38% to 67.19% for atrazine and simazine using the (Ru(OCTTPP))) and was also observed the transformation of herbicides in desethyl atrazine products (DEA) and the deisopropil atrazine (DIA). The monitoring data of catalytic reactions by UV-Vis revealed the stability of the catalysts (Fe(FTTPCl)) and (Ru(OCTTPP)) in oxidizing conditions of the reactions. The results obtained with gas chromatography coupled with mass spectrometry (GC-MS) using the electron impact ionization technique (EI), full scan, positive mode (EI+), associated this peak revealed molecular ion peak (m/z = 215, associated with atrazine [M]+ and major fragments (m/z): 200 (associated with the ion [M - CH3]+), 173 and 138, and the mass spectrum obtained after the oxidation reaction revealed the disappearance of the peak associated with the herbicides and formation of new peaks associated with byproducts fragments. Similarly, the identification of simazine was obtained in the positive mode (EI+) and been revealed molecular ion peak (m / z = 201) and the principal fragments (m / z): 186, 173 and 138
Mestrado
Tecnologia e Inovação
Mestra em Tecnologia
12
Leung, Kevin Shurch-Yee. « Adsorption interactions of s-triazine herbicides and natural organic matter by activated carbon / ». free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9988683.
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Irace, Sandrine. « Comportement des triazines et des phénylurées : étude des interactions herbicides-colloïdes ». Paris 6, 1998. http://www.theses.fr/1998PA066167.
Texte intégralRésumé :
Dans le cadre d'un programme de recherche du piren-seine, notre travail a porte sur l'etude des interactions des triazines et des phenylurees avec la matiere organique colloidale des eaux de surface (comportements geochimiques) et sur le suivi multiresidus de 23 pesticides d'une liste prioritaire regionale dans les eaux de surface du vannetin durant le printemps 1996. Dans la premiere partie, nous avons precise le role des colloides sur le transfert des pesticides dans differents types d'eau comportant des matrices fortement anthropisees pour acheres sur la seine et detritiques pour isles les meldeuses sur la marne. La distribution des triazines et des phenylurees entre les fractions colloidales (0,2 m-2 nm) et dissoutes (< 2 nm), isolees par ultrafiltration tangentielle a mis en evidence une retention des phenylurees chlorees : linuron, diuron, neburon sur les colloides 5 a 10 fois plus elevee que pour les triazines : simazine, atrazine, terbuthylazine, prometryne. La matiere organique d'acheres a revele une capacite de retention des pesticides environ 20 fois superieure a celle d'isles les meldeuses. Les phenomenes de retention sur les colloides des triazines et des phenylurees ont ete mis en relation avec leurs frequences d'apparition dans les eaux de surface afin d'expliquer leurs differences d'occurrences. Dans une seconde partie, les methodes d'analyse multiresidus ont permis d'identifier 14 herbicides extraits de la liste prioritaire de surveillance a l'echelle regionale dans les eaux de surface du vannetin, et de distinguer deux modes de transfert des herbicides. Avant les pluies de printemps, ce sont les eaux de la nappe alluviale qui alimentent en herbicides les eaux de surface du vannetin. Tandis qu'apres les pluies tardives du 18 mai succedant a une relative secheresse, ce sont les eaux de drainage qui transferent les herbicides des sols au vannetin.
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Sangwan, Jagbinder Singh. « Obtention in vitro de cellules puis de plantes résistantes a certains herbicides chez le datura innoxia mill. Et le nicotania tabacum l ». Paris 7, 1988. http://www.theses.fr/1988PA077149.
Texte intégralRésumé :
La mise au point d'un système pour la sélection in vitro de deux solanacées diploïdes et autogames résistantes a l'atrazine, au chlortoluron et au terbutryne, est décrite. Les effets de ces produits ont été détermines sur des cultures d'organes (explants différencies) et sur des cals (tissus indifférencies). Aucune sélection n'est possible a partir de disques foliaires, entre-nœuds, anthères et cals non chlorophylliens. On procede ensuite au repiquage des tissus sur un milieu organogène. On réalise le micro greffage des apex des tiges ainsi formées sur de jeunes plantes issues de germination. On met en évidence que le caractère de résistance est transmis a certains des embryons produits par les plantes greffées
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Grillo, Renato 1984. « Desenvolvimento de sistemas de liberação modificada para herbicidas triazínicos utilizando nanocápsulas poliméricas ». [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314420.
Texte intégralRésumé :
Orientador: Leonardo Fernandes FracetoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Muitas das novas tecnologias desenvolvidas atualmente envolvem a nanobiotecnologia, dentre elas, os sistemas carreadores nanoestruturados poliméricos. Os sistemas nanoestruturados poliméricos (SNP) agem como compartimentos transportadores de substâncias bioativas e apresentam tamanho inferior a 1 ?m. Estes sistemas têm a capacidade de alterar as propriedades físico-químicas dos compostos a eles incorporados, levando a algumas vantagens. Para herbicidas estes sistemas podem ser responsáveis pela redução na quantidade de substância química necessária para o controle de pragas, diminuição no risco de poluição ambiental, redução na quantidade de energia gasta, uma vez que se reduz o número de aplicações necessárias comparadas às formulações convencionais e aumento na segurança das pessoas responsáveis pela aplicação do produto no campo. Neste trabalho pretende-se introduzir esta nova abordagem tecnológica de sistemas de liberação modificada para herbicidas triazínicos, preparando e caracterizando dois tipos de nanocápsulas obtidas do polímero biodegradável poli(_-caprolactona) (PCL). Os herbicidas triazínicos escolhidos foram ametrina, atrazina e simazina devido a sua ampla utilização em plantações de cana-de-açúcar e milho no Brasil. Em uma primeira etapa deste projeto foram preparadas nanocápsulas pelo método deposição interfacial de polímero préformado e analisadas quanto sua eficiência de encapsulação, perfil de cinética de liberação, estabilidade físico-química e morfologia. A eficiência de encapsulação dos herbicidas nas nanocápsulas de PCL foi elevada, apresentando valores compreendidos entre 98% e 84% (m/m). O perfil de cinética de liberação do herbicida livre foi mais rápido, quando comparado com o herbicida associado às nanocápsulas. O mecanismo responsável pela liberação dos herbicidas neste sistema foi dado pelo processo de relaxamento das cadeias poliméricas. As suspensões coloidais de nanocápsulas apresentaram tamanho médio entre 200-300 nm, polidispersão baixa e valores de potencial zeta menor que -25 mV. As análises microscópicas mostraram que as nanocápsulas apresentaram-se esféricas, densas e sem agregados. Os espectros de infravermelho das nanocápsulas de PCL contendo herbicidas não apresentarambandas relacionadas aos herbicidas, evidenciando uma interação entre o composto bioativo e a nanopartícula. Na segunda etapa deste projeto foram preparadas nanocápsulas de PCL revestidas com diferentes concentrações de quitosana e encapsulou-se o herbicida atrazina ao sistema. A taxa de encapsulação, o perfil de cinética de liberação e a estabilidade físico-química das formulações também foram avaliados e observou valores de encapsulação compreendido entre 84% e 64% (m/m). O perfil de cinética de liberação do herbicida também foi alterado quando associado às nanocápsulas revestidas e o mecanismo de liberação foi dado pelo processo de difusão e relaxamento das cadeias poliméricas. A estabilidade das formulações foi alterada conforme mudança na concentração de quitosana. Portanto considerando alguns destes resultados e pensando na larga utilização de herbicidas no mundo, o seu uso na agricultura na forma associada a sistemas carreadores de liberação modificada pode ser interessante e bastante promissor do ponto de vista ecológico como econômico
Abstract: Many of the new technologies developed today involve nanobiotechnology, among them, nanostructured polymeric carrier systems. Nanostructured polymeric systems (PNS) compartments act as carriers of bioactive substances and have size less than 1 micrometers. These systems have the ability to change the physicochemical properties of the compounds incorporated into them, leading to numerous advantages. For these systems herbicides may be responsible for the reduction in the amount of chemical needed for pest control, decreased risk of environmental pollution, reduction in the amount of energy expended, since it reduces the number of applications required compared to conventional formulations and increase the safety of persons responsible for applying the product on the field. This study intended to introduce this new technology approach for sustained release systems triazine herbicides, preparing and characterizing nanocapsules produced with poly (_-caprolactone) (PCL). The herbicides were chosen ametryn, atrazine and simazine because of its wide use in sugar cane and corn crops in Brazil. In a first stage of this study was prepared nanocapsules by interfacial polymer deposition method preformed and analyzed for their encapsulation efficiency, release kinetics profile, physical and chemical stability and morphology. The encapsulation efficiency of herbicides in PCL nanocapsules was good, with values between 98% and 84%. The kinetic profile of free herbicide release was modified compared with the herbicide associated with nanocapsules. The mechanism responsible for the release of herbicides in this system was given by the process of relaxation of polymer chains. The colloidal suspensions of nanocapsules present a mean size between 200-300 nm, low polydispersity and zeta potential values lower than -25 mV. The microscopic analysis showed that the nanocapsules were spherical and didn't present aggregates. The infrared spectra of nanocapsules-PCL containing herbicides showed no bands related to herbicides, showing an interaction between the nanoparticle and the bioactive compound. In the second stage of this study was prepared PCL nanocapsules coated with different concentrations of chitosan and encapsulated to the herbicide atrazine to the system. The rate of encapsulation, the profile of release kinetics and physical and chemical stability of the formulations were also evaluated and observed values of encapsulation between 84% and 64%. The profile of release kinetics of the herbicide was also altered when associated with nanocapsules coated and release mechanism was given by the process of diffusion and relaxation of polymer chains. The stability of the formulations was changed according to change in the concentration of chitosan used. So considering some of these results and considering the wide use of herbicides in the world, its use in agriculture as the associated systems for the controlled release carrier can be interesting and very promising in terms of ecological and economical
Mestrado
Bioquimica
Mestre em Biologia Funcional e Molecular
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Van, Zwieten Lukas. « Enhanced biodegradation of phenoxyacetate and triazine herbicides by plant-microbial rhizoplane associations and adapted soil microorganisms ». Thesis, The University of Sydney, 1995. https://hdl.handle.net/2123/26900.
Texte intégralRésumé :
Strategies for the enhanced biological degradation of pesticides were examined in this research project. In one approach, the concept of the plant—microbial rhizosphere association was investigated as a laboratory model using the herbicide 2,4-D as a test compound. In another, an enhanced degradation of the recalcitrant herbicide atrazine was shown. Here, two microbial populations each capable of rapid atrazine metabolism were studied.
The metabolism of 2,4-D by bacteria associated with the root system of wheat and canola seedlings was demonstrated in this study using a hydroponic system as well as a solid medium of sand and gravel. Significant and rapid 2,4-D metabolism (near 100% within 24h) was found in all hydroponic systems where the 2,4-D degrading microorganisms, Acinetobacter baumannii pJP4 transconjugant, Alcaligenes eutrophus and Azospirillum brasilense pIP4 transconjugant were associated with the roots.
The metabolism of 2,4-D by Azospirillum brasilense pJP4 transconjugant associated with wheat was less rapid than associations with the other 2,4-D degrading bacteria. There was little difference in the rates of degradation between the hydroponic system and the sand/gravel mixture.
The colonisation of the roots of seedlings by microbes was studied by both fluorescence and laser scanning confocal microscopy. Colonisation was often prolific without favoured areas of attachment on the root. A pre-treatment of seedlings with a synthetic auxin which formed para-nodular structures had little effect on the nature of colonisation. Counts of colony forming units, however, established that there was an increase of an order in magnitude of cells per root system when the plants were pretreated with this synthetic auxin. An average of 5.5 x 106 viable cells of 2,4-D degrading Acinetobacter baumannii were counted on para-modulated wheat root systems.
It was demonstrated that the colonisation of the rhizosphere by suitable microbes could protect canola seedlings against phytotoxic effects of the applied herbicide. Whether this bio-safening effect will be seen in solid media or in field situations with these nonleguminous plants was not investigated.
Significant rates of atrazine degradation either in the laboratory or in the field have rarely been reported. Attempts were therefore made to obtain microbes capable of such metabolism. These attempts had the ultimate goal of providing microbes for application in the model plant microbial rhizosphere association. Two microbial cultures, each capable of rapid atrazine metabolism, were obtained and studies of the metabolic processes were conducted.
Rhodococcus sp. NI86/21 metabolised atrazine within l44h to two N—dealkylated products, desisopropylatrazine and desethylatrazine. Mineralisation of the ethyl-14C labelled sidechain to 14CO; was demonstrated, accounting for 25% of the total applied label in the broth culture. Desisopropylatrazine was shown to be the major metabolite. Desethylatrazine was shown as a terminal metabolite in the degradation of atrazine by Rhodococcus sp. N186/21, accumulating in the broth. In other studies using it as the substrate, no firrther metabolism was found. Desisopropylatrazine was also indicated to have been a terminal metabolite as it too accumulated in the broth.
The metabolism of prometryn, a thio-ester (non-chlorinated) s-triazine was also investigated in these studies. Although Rhodococcus Sp. N186/21 did not rapidly degrade prometryn under similar conditions to those used with the atrazine assays, a mono-N-dealkylated metabolite was identified by mass-spectrometry. Possibly, prometryn was toxic to the Rhodococcus at the concentration used (lOug mL'l), as only minimal growth of the bacteria in the broth was observed by increased absorbance. Such a toxic effect was likely to have inhibited the N-dealkylation metabolism of the prometryn.
In another approach, soil from a pesticide sullage site on a farm in northern NSW was assayed for its atrazine metabolising ability. Although there was no initial activity, after 30 months of perfirsion of the soil with a concentrated solution of the herbicide, it had acquired the ability to rapidly mineralise atrazine. A rapid conversion of the three carbons in the s—triazine ring to C02 was demonstrated using radiolabelled atrazine. Also, the labelled carbon in the ethyl sidechain of atrazine was rapidly metabolised to CO2.
The sidechain 14C label was mineralised to 14C02 at a slower rate than the carbons in the ring. It was demonstrated that there was a likelihood of the sidechain carbon being incorporated into an unextractable intermediate metabolite, which was subsequently also less susceptible to attack by the microorganisms. There were no significant metabolites of atrazine accumulated in the broth. The likely presence of hydroxyatrazine was noted in the assay using uniformly ring—labelled [14C] atrazine. Hydroxyatrazine was also identified in the assay with ethyl-sidechain labelled [14C] atrazine, however, the amount detected was less.
The presence of atrazine at 25pg mL-l inhibited nitrification reactions in the soil, however, at a saturating concentration of SOug mL-l there was some ammonia oxidation noted. Attempts to isolate single bacterial colonies capable of the metabolism of atrazine were unsuccessful.
Although there was insufficient time to utilise these microbial cultures in the plant microbial rhizosphere associations, studies on the metabolism of atrazine have sufficiently characterised the nature of biodegradation to suggest that plant-microbial associations can be confidently tested in fiiture experiments.
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BENVENUTO, FEDERICA. « Integrated study of chemical, hydrological and biological aspects of impaired rivers to support restoration strategies ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2009. http://hdl.handle.net/10281/7504.
Texte intégralRésumé :
The human presence and activities affect the environmental quality of water bodies in different ways. Pressures concern various aspects of the overall environmental quality and their effects are cumulative and synergic.
That’s why an integrated approach is needed to understand and assess the importance of each kind of stressors and to define restoration strategies.
The research work carried out in the last three years and shown in this thesis concerns impaired river ecosystems and includes, in particular:
1) Integrated study of chemical, hydrological and biological aspects of impaired rivers, especially those affected by multiple alterations in urban environments and, thus, wastewater treatment plant effluent dominated. A case study (Lura stream) is presented.
2) Development of analytical methods for determining organic micropollutants (PAHs, triazines and their main transformation products) in a wide range of surface and wastewater samples (coming from different environments in Italy and Spain) and, consequently, for evaluating the contamination from wastewater treatment plant discharges.
3) Evaluation of the organic micropollutant removal efficiencies of wastewater treatment plants and comparison of the concentrations measured in effluent samples to the environmental quality objectives fixed for surface waters, as most of the receptor flow is made by the discharged effluent itself.
4) Study of the performance of a demonstration scale constructed wetland in removing inorganic and organic contamination from wastewater treatment plant effluents, as a possible strategy for impaired river restoration.
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Devault, Damien Lim Puy Pinelli Eric. « Approche spatio-temporelle de la contamination par les herbicides de pré-levée du biotope de la Garonne Moyenne ». Toulouse : INP Toulouse, 2008. http://ethesis.inp-toulouse.fr/archive/00000578.
Texte intégral
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Douglass, James F. « Biomineralization of atrazine and analysis of 16S rRNA and catabolic genes of atrazine-degraders in a former pesticide mixing and machinery washing area at a farm site and in a constructed wetland ». The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1440373757.
Texte intégral
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Peterlini, Mariana Frem 1980. « Avaliação morfológica em brânquias e tegumento como biomarcadores da intoxicação aguda por atrazina em alevinos de pacu, Piaractus mesopotamicus ». [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317907.
Texte intégralRésumé :
Orientador: Sarah AranaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: A agricultura intensiva no Brasil tem aumentado o risco de contaminação dos recursos hídricos e dos organismos aquáticos por agroquímicos. Esse é o caso da atrazina, detectada em alta frequência em rios e córregos da região. Assim, neste trabalho, o pacu (Piaractus mesopotamicus) foi escolhido como bioindicador por sua importância econômica e ecológica em Bacias do Pantanal. As brânquias e o tegumento foram aqui avaliados como biomarcadores da toxicidade induzida por atrazina, uma vez que estes órgãos se encontram em contato direto com o ambiente aquático. Para avaliar a sensibilidade de alevinos de pacu e determinar a Concentração Letal Média (CL50) à atrazina foram conduzidos experimentos, em duplicata, em sistema estático por 96 horas, com as seguintes concentrações: 0,0; 13,2; 17,6; 22,0; 26,4; 30,8; 35,2; 39,6 mgL-1. A CL50 obtida para a atrazina foi de 28,58 mgL-1 (96h). Foram realizadas análises anatomopatológica, histopatológica qualitativa e semi-quantitativa para brânquias e análises anatomopatológica e histopatológica qualitativa para o epitélio tegumentar. Amostras de brânquia e de pele dorsal e ventral foram fixadas em Bouin e incluídas em parafina. Para o grupo controle não foi registrada qualquer alteração com os métodos empregados. Os alevinos expostos à atrazina apresentaram alterações comportamentais como: escurecimento da pele, boquejamento intenso e distúrbios motores, além disso, nesses aquários houve constante presença de muco na água; e, alterações anatomopatológicas, como: hiperemia na pele, dilatação da região ventral, presença de líquido no estômago e ascite sanguinolenta. Nas brânquias dos grupos tratados foram observadas as seguintes alterações morfológicas: edema e afastamento na região interlamelar, hipertrofia e hiperplasia na região interlamelar, destacamento do epitélio respiratório, hipertrofia de células do epitélio respiratório, congestão, telangiectasia e fusão de lamelas secundárias. Na pele dorsal e ventral dos grupos tratados não se observou alteração histopatológica. As alterações motoras observadas são provavelmente decorrentes do efeito neurotóxico da atrazina. As análises branquiais confirmam o comprometimento respiratório e de osmoregulação nesse órgão, sendo que a análise semi-quantitativa indicou a hipertrofia de células do epitélio respiratório como a lesão mais severa. Finalmente, as brânquias mostraram-se biomarcadores adequados na avaliação dos efeitos tóxicos da atrazina em pacu e o valor da CL50 sugere que a atrazina é levemente tóxica para o pacu, porém pelos demais resultados observados, se infere que só analisar a mortalidade não é o suficiente para determinar o dano causado por agrotóxicos em peixes, assim, recomenda-se o emprego de vários biomarcadores, como por exemplo, análise de vários outros órgãos. Os resultados obtidos reforçam a importância de estudos desta natureza, para embasar medidas ambientais preventivas e reguladoras quanto ao uso desse herbicida
Abstract: The intensive agriculture in Brazil has caused growing increase of pollution risks of hydric resources and the aquatic organisms by agrochemicals. This is the case of atrazine, detected in high frequency in the rivers and streams. Therefore, in this research, the pacu (Piaractus mesopotamicus) was chosen by bioindicator because of its great economic and ecological importance to the water ecosystem of the Pantanal region. The gills and skin were assessed here as biomarkers of induced toxicity by atrazine, considering that these organs are in direct contact with the aquatic environment. To evaluate the sensitivity of pacu fingerlings and determine the Median Lethal Concentration (LC50) by atrazine, experiments were conducted, performed in duplicate, in static system for 96 hours, with the following concentrations: 0.0; 13.2; 17.6; 22.0; 26.4; 30.8; 35.2; 39.6 mgL-1. The LC50 for pacu was 28.58 mgL-1 (96h). Anatomopathological, qualitative histopathological and semiquantitative histopathological analyses were performed for the gills, and anatomopathological and qualitative histopathological analysis were performed for the skin epithelium. Gills and dorsal and ventral skin samples were fixed in Bouin and processed for the inclusion in paraffin. The control group did not register any other alterations with the methods used. The fingerlings exposed to atrazine presented behavioral changes, such as: darkening of the skin, an increase in the frequency of gasping and motor disturbances. Furthermore, these aquariums presented the constant presence of mucus in the water; and, anatomopathological alterations, such as: skin hyperemia, dilation of the ventral region, the presence of liquid in the stomach and bloody ascites. In the gills of treated groups were found the following morphological alterations: edema and spacing in the interlamellar region, hypertrophy and hyperplasia in the interlamellar region, epithelial lifting, hypertrophy of respiratory epithelium cells, congestion, telangiectasis and fusion of the secondary lamellae. For dorsal and ventral skin of treated groups no histological alterations were observed. The motor alterations observed are probably due to the neurotoxic effects of atrazine. The gills analysis confirm respiratory and osmoregulatory compromise in this organ, noting that semi-quantitative analysis indicated the hypertrophy of respiratory epithelium cells as the most severe lesion. Finally, the gills showed adequate biomarkers in the assessment of toxic atrazine effects in pacu and the LC50 value suggests that atrazine is lightly toxic to pacu. However, by other results observed, it is concluded that analyzing the mortality index alone is not enough to determine the damages caused by agrotoxics in fishes, so the use of other biomarkers is recommended, like for instance, analysis some other organs. The results obtained reinforce the importance of research of this nature, in order to establish preventive and regulatory environmental measures regarding the use of this herbicide
Mestrado
Histologia
Mestra em Biologia Celular e Estrutural
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Lerivrey, Jacques. « Étude de la complexation des systèmes métal - S-triazines - D-glucosamine : mise en évidence de complexes ternaires ». Lille 1, 1985. http://www.theses.fr/1985LIL10123.
Texte intégralRésumé :
L'objectif principal de ce travail est l'étude de la complexation du système ternaire cuivre (II) - prométone - D-glucosamine en solution aqueuse dans le but de comprendre le mécanisme d'assimilation des herbicides par les plantes. L'étude préliminaire des systèmes binaires Cu(II) - prométone et Cu (II) - D-glucosamine s'est avérée nécessaire. Nous avons mis en oeuvre une technique potentiométrique et développé des programmes de traitement de données expérimentales. Les résultats potentiométriques sont corroborés par différentes techniques spectroscopiques qui précisent la nature des liaisons impliquées dans les complexes. La prométone (PR), herbicide de la famille des s-triazines, conduit avec l'ion cuivrique à la formation d'un complexe stable de type CuL2. Avec la D-glucosamine (GA), sucre aminé simple, nous avons mis en évidence des complexes du type CuL2 et CuL2H-2. L'étude du système ternaire Cu(II) - PR - GA montre la formation du complexe mixte Cu(PR)(GA), très stable dans la zone des pH neutres. L'herbicide préalablement complexé avec le cuivre (II) peut réagir avec les sucres aminés présents dans les parois cellulaires des plantes et faciliter son assimilation. D'autre part, nous avons étudié l'influence des substituants de la molécule de 1, 3, 5 s-triazines dans sa complexation avec Cu(II) et l'influence de la nature du métal sur les phénomènes de coordination avec la D-glucosamine.
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Soares, Francielle Queiroz. « Desenvolvimento de fases monolíticas para métodos de extração aplicados a análise LC-UV de herbicidas em amostras de água ». Universidade Federal de Goiás, 2018. http://repositorio.bc.ufg.br/tede/handle/tede/8598.
Texte intégralRésumé :
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Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG
Monolithic polymers can be defined as continuous porous polymers, synthesized in situ in a mold. These materials have been used in chromatographic applications due to the combination of high surface area with excellent permeability and mass transport properties. In this work, monolithic polymers based on styrene and divinylbenzene were synthesized by thermal initiation via bulk polymerization in the presence of different diluents; and via high internal phase emulsion polymerization in presence and absence of toluene as diluent. The monoliths produced via bulk polymerization, which were synthesized in the presence of binary mixtures tetrahydrofuran/decanol and toluene/decanol as polymerization diluents in the ratio 15:85 (v/v) showed mechanical resistance to be applied as extractive phases. Both formulations produced polymers with macroporous characteristics and the tetrahydrofuran/decanol mixture presented larger channels, resulting in higher permeability, in this way it was used as extraction phase for the technique of preparation of samples based on a device of sorptive extraction of micropipette tip (DPX) applied to the determination of triazines in water samples. Under optimized conditions the absolute recovery for the triazines varied from 28 to 64%. The monoliths produced by high internal phase emulsion polymerization showed macroporosity. We have found that the effect of the solvent is more significant for the increase in surface area and the volume and mean diameter of pores than the effect of the reduction of these by the increase in velocity. With this, the monolith prepared in the presence of toluene at a speed of 3000 rpm obtained a larger surface area and a larger volume and pore diameter, resulting in a higher permeability. The surface of this monolith was modified with polypyrrole, to verify this film on the selectivity of the resulting phase. When submitted to the extraction process using solid phase extraction devices (SPE), the monolith covered with PPY films presented better extraction efficiency and its parameters were optimized for determination of triazines in water samples by the SPE/LC-UV method (SPE/high performance liquid chromatography with UV-vis detection). According to the figures of merit evaluated, the proposed SPE/LC-UV method presented linearity in the concentration range of 0.5-50 ng.mL-1 and absolute recovery of 75 to 105%, with precision demonstrated by the coefficient of variation lower than 15%. The limit of quantification of the method was 0.5 ng.mL-1 for all the analytes. Thus, it was possible to develop new low-cost monolithic phases with chemical and mechanical resistance and physicochemical characteristics suitable for use as extractive phase in the miniaturized technique of preparation of DPX samples, as well as SPE. The developed phases were evaluated for the determination of triazines in water samples with adequate selectivity and sensitivity. Based on the results, the developed phases present themselves as promising alternative to the commercial extractive phases.
Os polímeros monolíticos podem ser definidos como polímeros contínuos altamente porosos, sintetizados in situ em um molde. Esses materiais têm sido empregados em aplicações cromatográficas devido a combinação de alta área superficial com excelentes propriedades de permeabilidade e transporte de massa. Nesse trabalho, polímeros monolíticos a base de estireno e divinilbenzeno foram sintetizados por iniciação térmica, via polimerização em massa na presença de diferentes diluentes; e via polimerização em emulsão de alta fase interna, na presença e na ausência de tolueno como diluente. Os monolitos produzidos via polimerização em massa, que foram sintetizados na presença das misturas binárias tetrahidrofurano/decanol e tolueno/decanol como diluentes de polimerização na proporção 15:85 (v/v) apresentaram resistência mecânica para serem aplicados como fases extratoras. Ambas as formulações produziram polímeros com característica macroporosa e a mistura tetrahidrofurano/decanol apresentou canais maiores, resultando em menor resistência à vazão, desta forma este foi utilizado como fase extratora para técnica de preparo de amostras baseada em dispositivo de extração sortiva em ponteira (DPX) aplicado à determinação de triazinas em amostras de água. Nas condições otimizadas a recuperação absoluta para as triazinas variou de 28 a 64%. Para os monolitos produzidos via polimerização em emulsão de alta fase interna, o efeito do solvente é mais significativo para o aumento da área superficial e do volume e diâmetro médio de poros do que o efeito da redução desses pelo aumento da velocidade de agitação. Com isso o monolito preparado na presença de tolueno na velocidade de 3000 rpm obteve maior área superficial e maior volume e diâmetro de poro, resultando em menor resistência à vazão e sua superfície foi modificada com polipirrol. Quando submetidos ao processo de extração empregando dispositivos de extração em fase sólida (SPE), o monolito recoberto com filmes de PPY, apresentou maior eficiência de extração sendo então seus parâmetros otimizados para determinação de triazinas em amostras de água pelo método SPE/LC-UV (SPE/cromatografia líquida de alta eficiência com detecção UV-vis). Segundo as figuras de mérito avaliadas o método SPE/LC-UV proposto, apresentou linearidade na faixa de concentração de 0,5-50 ng.mL-1 e recuperação absoluta de 75 a 105 %, com precisão demonstrada pelos coeficientes de variação menores que 15%. O limite de quantificação do método foi de 0,5 ng.mL-1 para todos os analitos. Assim sendo, foi possível desenvolver novas fases monolíticas de baixo custo com resistência química e mecânica e características físico-químicas adequadas para emprego como fase extratora em técnica miniaturizada de preparo de amostras DPX, assim como em SPE. As fases desenvolvidas foram avaliadas para determinação de triazinas em amostras de água apresentando seletividade e sensibilidade adequada. Com base nos resultados, as fases desenvolvidas apresentam se como promissora alternativa às fases extratoras comerciais.
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BOTTERI, LUCIO. « Presenza di erbicidi triazinici e loro metaboliti nelle acque di falda di aree maidicole italiane ». Doctoral thesis, Università Cattolica del Sacro Cuore, 2021. http://hdl.handle.net/10280/92058.
Texte intégralRésumé :
La presenza di pesticidi nelle acque di falda è emersa come un importante problema ambientale negli ultimi decenni. In base a “Rapporto nazionale pesticidi nelle acque - Dati 2015-2016” (ISPRA, 2018), in Italia, gli erbicidi triazinici e i loro metaboliti sono tra le sostanze identificate con più frequenza nelle acque, sebbene l’atrazina sia stata bandita nel 1992 e l’utilizzo di terbutilazina sia sottoposto a severe restrizioni. Lo scopo di questo progetto è valutare e quantificare la presenza di atrazina, terbutilazina e dei loro metaboliti nelle acque di falda in aree maidicole italiane. I risultati dimostrano come le molecole oggetto di studio siano state frequentemente individuate nei campioni di acqua di falda, anche se a concentrazioni inferiori al limite stabilito dalla Commissione Europea. Considerando che l’utilizzo di questi erbicidi è proibito o fortemente regolamentato, è interessante valutare il loro comportamento in una scala temporale pluriennale al fine di mettere in evidenza la contaminazione delle acque di falda dovute all’uso diffuso e alla persistenza ambientale di tali molecole.The presence of pesticides in groundwater has emerged as an important environmental issue in the last decades. According to “Rapporto nazionale pesticidi nelle acque - Dati 2015-2016” (ISPRA, 2018), in Italy triazine herbicides and their metabolites are among the substances most frequently detected in water. While terbuthylazine is still used under restriction, atrazine was banned in 1992. The aim of research project is to investigate the presence of atrazine, terbuthylazine and their metabolites in groundwater in Italian maize-growing areas in order to supply data and information on the groundwater quality. The results show that atrazine, terbuthylazine and their metabolites were often detected in groundwater, even if their concentrations were below the limit established by European Commission. Considering these molecules are banned or heavily regulated, it is interesting to evaluate their behavior on a multiannual time scale in order to highlight the groundwater contamination due to the widespread use and to the environmental persistence of these substances.
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BOTTERI, LUCIO. « Presenza di erbicidi triazinici e loro metaboliti nelle acque di falda di aree maidicole italiane ». Doctoral thesis, Università Cattolica del Sacro Cuore, 2021. http://hdl.handle.net/10280/92058.
Texte intégralRésumé :
La presenza di pesticidi nelle acque di falda è emersa come un importante problema ambientale negli ultimi decenni. In base a “Rapporto nazionale pesticidi nelle acque - Dati 2015-2016” (ISPRA, 2018), in Italia, gli erbicidi triazinici e i loro metaboliti sono tra le sostanze identificate con più frequenza nelle acque, sebbene l’atrazina sia stata bandita nel 1992 e l’utilizzo di terbutilazina sia sottoposto a severe restrizioni. Lo scopo di questo progetto è valutare e quantificare la presenza di atrazina, terbutilazina e dei loro metaboliti nelle acque di falda in aree maidicole italiane. I risultati dimostrano come le molecole oggetto di studio siano state frequentemente individuate nei campioni di acqua di falda, anche se a concentrazioni inferiori al limite stabilito dalla Commissione Europea. Considerando che l’utilizzo di questi erbicidi è proibito o fortemente regolamentato, è interessante valutare il loro comportamento in una scala temporale pluriennale al fine di mettere in evidenza la contaminazione delle acque di falda dovute all’uso diffuso e alla persistenza ambientale di tali molecole.The presence of pesticides in groundwater has emerged as an important environmental issue in the last decades. According to “Rapporto nazionale pesticidi nelle acque - Dati 2015-2016” (ISPRA, 2018), in Italy triazine herbicides and their metabolites are among the substances most frequently detected in water. While terbuthylazine is still used under restriction, atrazine was banned in 1992. The aim of research project is to investigate the presence of atrazine, terbuthylazine and their metabolites in groundwater in Italian maize-growing areas in order to supply data and information on the groundwater quality. The results show that atrazine, terbuthylazine and their metabolites were often detected in groundwater, even if their concentrations were below the limit established by European Commission. Considering these molecules are banned or heavily regulated, it is interesting to evaluate their behavior on a multiannual time scale in order to highlight the groundwater contamination due to the widespread use and to the environmental persistence of these substances.
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Devault, Damien. « Approche spatio-temporelle de la contamination par les herbicides de pré-levée du biotope de la Garonne Moyenne ». Toulouse, INPT, 2007. http://ethesis.inp-toulouse.fr/archive/00000578/.
Texte intégralRésumé :
L'application au milieu naturel d'un protocole de dosage des herbicides dans le sédiment a permit de dresser une cartographie de la contamination des sédiments et des eaux de surface appariées par les produits phytosanitaires. Au travers de ce premier état de la contamination du biotope aquatique, l'étude identifiera et caractérisera les sites où la charge en pesticides est la plus élevée : dans un contexte urbain et dans les discontinuités majeures propices à l'accumulation du sédiment (barrages). Des investigations furent alors menées pour comparer l'activité biologique du sédiment à sa charge en herbicides. Des carottages furent réalisés à des lieux marquants de la Garonne via la diagénèse précoce (Malause)Application to the natural environment of a protocol of proportionning of the herbicide in sediment made possible to draw up a cartography of the sediment and surface water contamination paired by the plant health products. Through this first state of the aquatic biotope contamination, the study will identify and characterize the sites where the pesticides accumulation is highest: in an urban context and in major discontinuities favourable to the sediment accumulation (dams). Investigations were carried out to compare the biological activity of the sediment with its herbicide concentration. Corings were carried out with the outstanding ones of the Garonne via the early diagenesis (Malause)
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Ducruet, Jean-Marc. « Contribution à l'étude du mécanisme d'action des herbicides inhibiteurs du photosystème II, de type DCMU ». Paris 11, 1986. http://www.theses.fr/1986PA112041.
Texte intégralRésumé :
L'induction de fluorescence chlorophyllienne a été utilisée pour le dosage d'herbicide du type DCMU dans des feuilles entières. Les conditions de la mesure et l'analyse des cinétiques sont décrites. Cette technique a été également appliquée à l'étude des effets de chocs thermiques de quelques minutes entre 35°C et 50°C sur des feuilles de plantes résistantes et sensibles aux triazines. Pendant l'échauffement, une inhibition de type DCMU apparaît uniquement chez les résistants et montre que la mutation altère la structure de la protéine-cible B. Après l'échauffement, des modifications irréversibles complexes sont observées chez les résistants et les conséquences agronomiques possibles sont envisagées. L'analyse comparée des relations structure-activité chez les résistants et les sensibles aux triazines montre que la distinction entre inhibiteurs de type urées-amides et de type triazines n'est pas absolue. Les motifs -NH-CO- et -NH-CN- de ces deux groupes pourraient donc jouer un rôle homologue. Ils sont capables de former, notamment, une double liaison hydrogène pouvant rendre compte de l'énergie d'interaction au niveau du site d'action. Des différences entre les propriétés d'interaction de ces deux motifs apportent des éléments d'explication du phénomène de la résistance. Des modèles d'interaction des inhibiteurs et des quinones avec un site, éventuellement identique, de la protéine-cible B sont proposés à titre exploratoireChlorophyll fluorescence induction was used to titrate DCMU-like herbicides in whale leaves. The experimental conditions and the analysis of kinetics are described. This method was also applied in studying the effects of thermal shocks (35°C to 50°C for several minutes) on leaves of triazineresistant and -susceptible plants. During heating, a DCMU-like inhibition of electron transfer was observed in the resistant leaves, which shows that the mutation changes the shape of the B target-protein. After heating, complex irreversible damages were observed in resistant leaves and the possible agricultural consequences are considered. The comparative analysis of structure-activity relationships in triazineresistant and -susceptible chloroplasts demonstrated that there is not a clear cut difference in the behavior of urea-amide and triazine inhibitors towards resistance. The -NH-CO- and -NH-CN- moieties in these two groups could play an homologous role. In particular, they are able to form double hydrogen bonds, the strength of which is compatible with the interaction energy at the binding site. Differences in the interaction properties of these two moieties could provide some pieces of explanation of the resistance phenomenon. Tentative mechanisms of interaction of inhibitors and quinones with a binding site, possibly unique, on the B target-protein are proposed
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Urio, Ricardo de Prá. « Cromatografia a líquido por injeção sequencial para a determinação de herbicidas triazínicos e metabólitos da atrazina explorando o uso de cela de longo caminho óptico e monitoramento on-line em estudos de adsorção ». Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-31082011-143740/.
Texte intégralRésumé :
Estudou-se o emprego da Cromatografia a Líquido por Injeção Seqüencial (SIC) explorando o uso de uma cela de longo caminho óptico com guia de onda (LCW) de 100 cm para a melhora dos limites de detecção (LOD) e quantificação (LOQ) na determinação de atrazina (ATR), propazina (PRO) e simazina (SIM). Para isto, utilizou-se uma fase móvel com composição de 44:56 (v v-1) metanol : tampão acetato de amônio 1,25 mM, pH 4,7, coluna monolítica e a detecção espectrofotométrica em 238 nm. Obtiveram-se valores de LOD e LOQ, respectivamente, de 1,76 e 5,86 µg L-1 para ATR, 4,51 e 15 µg L-1 para PRO e 2,25 e 7,5 µg L-1 para SIM. Com o emprego da cela de longo caminho óptico os valores de LOD ficaram abaixo dos recomendados pela US-EPA, que permite para águas potáveis uma concentração de 3 µg L-1 para ATR, 4 µg L-1 para SIM e 10 µg L-1 para PRO. Realizaram-se estudos de adsorção de SIM, PRO e ATR e seus metabólitos desisopropilatrazina (DIA), desetilatrazina (DEA) e 2-hidroxiatrazina (HAT) em solo, ácido húmico e solo modificado com ácido húmico. Para isso foi utilizado um sistema de monitoramento on-line composto por um filtro tangencial e uma bomba peristáltica para circulação da suspensão. Foram realizados estudos cinéticos em duas etapas e, em ambas, foi utilizado um mix dos compostos com concentração inicial de 1,0 mg L-1 e gradiente de eluição passo a passo para a separação dos compostos utilizando três fases móveis com composições de 15 ou 28, 40 e 50% (v v-1) metanol : tampão acetato de amônio 1,25 mM pH 4,7. Na primeira etapa o tempo de contato entre triazinas e adsorventes foi de 90 min. Na segunda etapa foi utilizado apenas o solo como adsorvente e o tempo de contato foi de 24 h. Para a primeira etapa do estudo só foi possível aplicar modelo cinético de pseudo-segunda ordem, o qual permitiu estimar os valores de massa adsorvida de triazina por massa de adsorvente, sendo que o ácido húmico é o material com maior capacidade adsortiva (1470 ± 43µg g-1 para DIA a 2380 ± 51 µg g-1 para PRO). O composto mais adsorvido em solo é PRO (26,5 ± 0,1 µg g-1). A presença de ácido húmico no solo aumentou a adsorção de ATR (de 19,4 ± 0,7 para 23 ± 2 µg g-1), de HAT (10,9 ± 0,7 para 18 ± 2 µg g-1) e de PRO (26,5 ± 0,7 para 29,8 ±0,2 µg g-1), mas diminuiu a adsorção de SIM e não afetou DIA e DEA. No estudo com tempo de contato de 24 h foi possível aplicar modelos de pseudo-primeira e segunda ordem. Os resultados obtidos confirmaram a maior adsorção de PRO, seguidos da ATR. HAT, SIM, DEA e DIA apresentaram as menores taxas de adsorção em solo, sendo que os dois últimos apresentaram uma tendência de dessorção após 4 h de contato, tendo maior potencial de lixiviação para corpos d\'água próximos aos locais de aplicação.This work describes the use of Sequential Injection Liquid Chromatography (SIC) coupled to a long path length optical flow cell with 100 cm long Liquid Core Waveguide (LCW) to improve the limits of detection (LOD) and quantification (LOQ) for determination of atrazine (ATR), propazine (PRO) and simazine (SIM). Separation was achieved with a mobile phase composition of 44:56 (v v-1) methanol:1.25 mM ammonium acetate buffer, pH 4.7, monolithic column and spectrophotometric detection at 238 nm. The values of LOD and LOQ were, respectively, 1.76 and 5.86 µg L-1 for ATR, 4.51 and 15 µg L-1 for PRO and 2.25 and 7.5 µg L-1 for SIM. The LOD values achieved with the employment of long optical path cell were lower than those recommended by US-EPA, which allows for drinking water, maximum concentration levels of 3 µg L-1 for ATR, 4 µg L-1 for SIM and 10 µg L-1 for PRO. Adsorption of SIM, PRO and ATR, as well as their metabolites desisopropylatrazine (DIA), desethylatrazine (DEA) and 2-hidroxyatrazine (HAT) on soil, humic acid and soil modified with humic acidic was studied. An on-line monitoring system was assembled, composed of a tangential filter and a peristaltic pump for circulation of the suspension. Kinetic studies were carried out in two steps, and in both, it was used a mix of compounds with initial concentration of 1,0 mg L-1 and a stepwise gradient elution for separation of the compounds using three mobile phases with compositions of 15 or 28, 40 and 50% (v v-1) methanol: 1.25 mM ammonium acetate buffer, pH 4.7. In the first step the contact time between triazines and adsorbents was 90 minutes. In a second study made only with soil, the contact time was 24 h. Data obtained in the first stage of the study was only fitted to pseudo-second order kinetic equation, which allowed one to estimate the values of the adsorbed mass of triazine per mass of adsorbent. Humic acid was the material with higher adsorptive capacity (from 1470 ± 43 µg g-1 for DIA to 2380 ± 50 µg g-1 for PRO). In soil, PRO exhibited the highest adsorption (26.5 ± 0.1 µg g-1). The presence of humic acid in the soil increased adsorption of ATR (19.4±0.7 to 23±2 µg g-1), HAT (10.9 ± 0.7 to 18 ± 2 µg g-1) and PRO (26.5 ± 0.7 to 29.8 ± 0.2 µg g-1), but decreased adsorption of SIM, not affecting DIA and DEA. In the study with contact time of 24 h, it was possible apply pseudo-first and pseudo-second order equations for SIM, ATR and PRO. The results confirmed the greatest adsorption of PRO, followed by ATR. HAT, SIM, DEA and DIA had low rates of adsorption on soil, the latter two showed a trend of desorption after 4 h of contact, having the greatest potential for leaching to water bodies near to the places of application.
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Kleinschmitt, Adriana Regina Bohn. « Transporte e retenção de triazinas em compartimentos ambientais terrestres e aquáticos em área de milho no sistema de plantio direto ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2007. http://hdl.handle.net/10183/10391.
Texte intégralRésumé :
No sistema de plantio direto destaca-se o uso dos herbicidas atrazina (ATZ) e simazina (SIM) no controle de plantas daninhas na cultura de milho. O objetivo deste trabalho foi avaliar a dinâmica e a retenção de ATZ e de SIM em compartimentos ambientais terrestres e aquáticos de área de lavoura de milho sob plantio direto. Foram coletadas amostras da área de lavoura (palha, solo, sedimento e de água de escoamento superficial) com elevada e com baixa densidade de cobertura. Amostras de água e de sedimento dos açudes adjacentes às áreas de lavora também foram coletadas imediatamente após as duas primeiras chuvas ocorridas após a aplicação dos herbicidas. A dessorção das amostras sólidas foi realizada com solução de CaCl2 0,01mol L-1 e com metanol para determinação de ATZ e SIM fracamente e fortemente retidas, respectivamente. Amostras aquosas foram concentradas em colunas SPE (Extração em Fase Sólida). Visando avaliar o potencial de retenção dos compartimentos, foram realizadas isotermas de sorção de ATZ e SIM (5 a 50 mg L-1) na palha e no solo. Os herbicidas foram quantificados nos sobrenadantes por cromatografia gasosa. Na área com elevada densidade de cobertura, a ATZ e a SIM foram preferencialmente retidas pela palha de cobertura, enquanto que na área com baixa densidade de cobertura tanto o solo quanto a palha retiveram ATZ. A concentração das formas de ATZ e SIM fracamente retidas e de ATZ fortemente retida na palha de cevada decresceram acentuadamente após o 1° dia, tendendo a valores nulos aos 167 dias. A concentração de SIM fortemente retida aumentou consideravelmente entre o 3º e o 29º dia, decrescendo gradativamente até o 167º dia. Este comportamento foi relacionado com a sua liberação da palha devido à acelerada decomposição da mesma após a 1° chuva. A mineralização intensa da palha foi evidenciada pelo valor máximo da razão C/P, pelo mínimo da razão C/N e pelo aumento da aromaticidade a partir desta data. As concentrações elevadas de ATZ e SIM nas amostras de água do escoamento superficial (280 μg L-1) e água do açude (25 μg L-1) são um indicativo de que a ATZ e SIM foram transportadas da palha para a água que escoou sobre a mesma, alcançando cursos de água próximos à área agrícola. A palha de cevada apresentou maior capacidade de sorver ATZ e SIM do que o solo, e representa um importante retentor de triazinas no ambiente. Entre os dois herbicidas, a SIM apresentou maior afinidade pelo solo e pela palha de cevada, o que deve estar relacionado com sua maior hidrofobicidade.Pesticides like atrazine (ATZ) and simazine (SIM) are commonly employed for the control of weeds plants in maize cropped areas under notillage system. The main objective of this work was to evaluate the dynamic and retention of ATZ and SIM in aquatic and terrestrial environmental compartments of a maize cropped area under no-tillage. Samples from the cropped field (straw, soil and run-off sediment and water) were sampled from areas with a high and with a low cover straw density. Water and sediment samples were collected from the pond aside the cropped area, immediately after the two first precipitations that occurred after the pesticide application. The dessorption of the solid samples was performed with 0,01mol L-1 CaCl2 solution followed by methanol extraction to obtain ATZ and SIM that were weakly and strongly bonded, respectively. The aqueous samples and extracts were concentrated in SPE columns (solid phase extraction). In order to evaluate the retention potential of the terrestrial compartments, sorption isotherms of ATZ and SIM (5 to 50 mg L-1) were determined in the straw and in the soil. The herbicides in the supernatants were quantified by gas chromatography. In the high cover density area, ATZ and SIM were preferentially retained in the cover straw, while in the low cover density area both the soil and the straw retained ATZ. The concentrations of weakly retained ATZ and SIM and of the strongly retained ATZ in the barley straw, decreased drastically after the 1st day after herbicide application (daa), tending to zero at the 167th daa. The concentration of strongly retained SIM increased considerably between the 3rd and the 29th daa, and then decreased steadily till the 167th daa. This behavior was related to the SIM release from the straw due to its accelerated decomposition after the 1st rain. The intense mineralization of the straw was evidenced by the highest value of the C/P ratio, by the lowest C/N ratio and by the increase of the aromaticity, observed from this day on. The high concentrations of ATZ and SIM observed in the run-off water (280 μg L-1) and in the pond water (25 μg L-1) are indicative that ATZ and SIM were removed from the straw by the run-off water, reaching the water bodies nearby the cropped area. The barley straw showed a higher sorbing capacity of ATZ and SIM than the soil, and represents an important retainer of triazines in the environment. Among the two herbicides, SIM has a higher affinity to the barley straw than ATZ, which is probably related to the lower solubility in water.
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Chahboune, Rajae. « Transformation photochimique des sulfonylurées et des organophosphorés sous excitation de complexes aqueux de fer (III) : rôle du fer (II) et du peroxyde d'hydrogène ». Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22550/document.
Texte intégralRésumé :
Les différents rejets aqueux de types industriel, artisanal et/ou hospitalier, contiennent différents contaminants organiques ou inorganiques qu’il convient d’éliminer. Selon le type de l’industrie et de l’utilisation, ces rejets auront besoin de subir un ou plusieurs traitements. Il existe de nombreuses méthodes de traitement des eaux adaptées à chaque pollution et à chaque usage. Dans le cadre de ce travail, nous nous sommes intéressés à l’utilisation d’une méthode peu onéreuse qui met en jeu les ions ferriques, ions ferreux, oxygène moléculaire et la lumière solaire (Fe(III)/Fe(II)/O2/hν) pour induire la transformation de composés organiques appartenant à deux familles de pesticides : les sulfonylurées et les organophosphorés. L’objectif majeur de l’étude consiste à la compréhension du rôle des ions de fer(II) dans le processus photocatalytique largement reporté dans la littérature ainsi que d’identifier les principaux produits formés au cours du processus. L’étude de la dégradation des sulfonylurées par excitation UV du peroxyde a démontré, sans aucune surprise, une réelle efficacité du processus. La réaction met en jeu les radicaux hydroxyles qui ont été clairement mis en évidence et quantifiés sous irradiation continue et par photolyse laser. Le processus dépend de la concentration initiale du substrat, du pH et de la concentration du photoinducteur (H2O2). La présence dans le milieu de la plupart des ions inorganiques conduit à une inhibition partielle de la dégradation. Dans le cas des ions étudiés, l’ordre de la réactivité est SO42- > Cl- > NO3- > CO32- . Cet aspect est très important à considérer lorsqu’il s’agit de traiter des eaux par le procédé UV/H2O2 . Lors de l’étude du comportement photochimique du complexe [Fe(H2O)5(OH)]2+ sous excitation à 365 nm et en simulateur solaire, la principale espèce réactive mise en jeu est le radical hydroxyle. En présence de composés organiques, une dégradation totale a pu être obtenue et ceci même pour de faibles concentrations en complexe de fer(III) (1,0x10-6 mol L-1). Il y a donc une régénération in situ et sous irradiation du fer(III). L’ensemble des expériences entreprises a permis de montrer que la régénération met en jeu non seulement le fer(II) mais également l’oxygène. La présence simultanée du fer(III) à l’état de trace et du fer(II) joue un rôle clé. En effet, l’excitation du fer(III) permet la production d’état excités qui transfèrent l’énergie aux ions de fer(II). Ces derniers états excités de fer(II) réagissent avec l’oxygène moléculaire par un processus de transfert d’électrons pour générer du fer(III) et l’anion superoxyde. La solution se trouve ainsi de plus en plus enrichie en fer(III) au fur et à mesure de l’excitation lumineuse. Sur le plan analytique, nous avons utilisé la technique LC/MS et LC/ESI/MS2 pour appréhender la structure chimique des photoproduits formés par l’étude précise des processus de fragmentation. Parmi toutes les réactions habituelles du radical hydroxyl (hydroxylation du noyau aromatique, scission du pont sulfonylurée et déméthylation), nous avons montré que certaines sulfonylurées conduisent, en milieu légèrement acide, à un processus de scission du squelette triazinique. Une telle réaction a également pu être confirmée par des études théoriques au niveau B3LYP/6-31G (d,p). La présence simultanée d’un groupement methoxy et d’une amine secondaire adjacente au cycle triazine est une condition essentielle pour une telle ouverture. L’ouverture du cycle est une étape importante pour atteindre l’objectif de l’étude qui est d’obtenir la minéralisation des solutions et ainsi le traitement des rejets aqueux de types industriel, artisanal et/ou hospitalierWaste waters resulting from industrial and artisanal activities as well as from hospital discharges contain numerous toxic organic and inorganic contaminants that require efficient treatment. In the present work, we employed various combinations of ferric and ferrous ions, oxygen, hydrogen peroxide and sunlight (Fe(III)/Fe(II)/O2/hν) to induce the transformation of two pesticide families: sulfonylureas and organophosphorus. The main objective of the study was devoted to the role of iron(II) species in the whole transformation process and also to the elucidation of the generated byproducts. In a first step, we used the system H2O2/ hν as a preliminary process for the degradation of the pollutant. This allowed a complete and fast removal of sulfonylureas. The reaction mainly involves hydroxyl radicals that were identified and quantified by nanosecond laser photolysis technique. The process highly depends on the initial substrate concentration, pH and the concentration of the photoinductor (H2O2). The presence of inorganic ions that could be present in waste waters was shown to inhibit the degradation, in the following decreasing order: SO42- > Cl- > NO3- > CO32- . In a second step, the study of the photochemical behavior of the iron(III) aquacomplex, [Fe(H2O)5(OH)]2+, upon light excitation at 365 nm as well as by using a solar simulator also showed the generation of hydroxyl radical together with iron(II) species. A complete elimination of studied pesticides was obtained even at low concentrations of iron(III) complex (1,0x10-6 mol L-1), indicating the high efficiency of the process. To gain insight into the degradation mechanism, the evolution of iron species upon irradiation was investigated in the absence and in the presence of molecular oxygen. The results suggested that a regeneration mechanism of iron(III) occurs through two consecutives steps. First, the excitation of iron(III) in trace concentrations, leads to the formation of iron(II) excited states through energy transfer process followed an electron transfer process that involves molecular oxygen and iron(II) excited state. As a conclusion, the solution becomes more and more enriched by iron(III) via the light excitation and in the presence of oxygen revealing the photocatalytic behavior of [Fe(H2O)5(OH)]2+. Within this work, a special attention was also devoted to the identification of products formed during the above photocatalytic process. This was performed by using liquid chromatography coupled to tandem mass spectrometry LC/ESI/MS2. The close investigation of the fragmentation processes of the generated products, permitted the establishment of precise chemical structures. In addition to the classical degradation of sulfonylureas by hydroxyl radicals (hydroxylation of the aromatic ring, the scission of sulfonylurea bridge and demethylation) a ring opening of the triazine skeleton was also obtained. This was observed under acidic conditions and was clearly confirmed by theoretical studies at the B3LYP / 6-31G (d, p) level. This triazine scission was only obtained with sulfonylures that contain a methoxy group and a secondary amine adjacent to the triazine moiety. Such ring opening constitutes an important and fundamental step when decontamination or/and mineralization of waste waters are concerned
30
Dang, Hue Thi. « Investigation of herbicide resistance in oriental mustard (Sisymbrium orientale L.) in Australia ». Thesis, 2018. http://hdl.handle.net/2440/118239.
Texte intégralRésumé :
Oriental mustard (Sisymbrium orientale L.), called Indian hedge mustard in Australia, is an important broadleaf weed of southern Australia. It has become more difficult to control in field crops due to the evolution of herbicide resistance. This study investigated the extent of resistance to four different herbicide modes of action, used to control oriental mustard in Australia. Herbicide resistance status was determined in 75 populations collected in southern Australia from 2010 to 2016 with resistance confirmed to herbicides inhibiting acetolactate synthase, photosystem II, phytoene desaturase (PDS) and auxinic herbicides. Populations resistant to PS-II, PDS-inhibitors and auxinic herbicides and two known susceptible populations (S1 and S2) were used to investigate the level of resistance, its mechanism, inheritance and fitness cost associated with resistance. Populations P17 and P18 were 311 and 315-fold, respectively, more resistant to atrazine than the susceptible populations as determined by the comparisons of their LD50 values. However, there was no resistance detected in these populations to diuron. Sequencing of the chloroplastic psbA gene identified a missense mutation of serine 264 to glycine in both herbicide-resistant populations, known to confer high-level of atrazine resistance in other species. P2 and P13 populations were 81 and 67-fold more resistant to 2,4-D at the LD50 level compared to the susceptible populations, respectively. No predicted amino acid modification was detected in sequences of potential target-site genes [Auxin binding protein (ABP), Transport inhibitor response 1 (TIR 1) and Auxin F-box protein 5 (AFB5)]. Further studies showed resistant populations had reduced 2,4-D translocation compared to the susceptible populations. At 72 h after herbicide treatment, 77% of [14C]2,4-D was retained in the treated leaf in the resistant population compared to 32% of [14C]2,4-D retention in the susceptible populations. Studies on inheritance of resistance to PDS-inhibitors confirmed that resistance to diflufenican in P3 population is inherited as a single dominant gene trait. Likewise, resistance to diflufenican and picolinafen in population P40 is also due to a single dominant gene. Resistance to 2,4-D in populations P2 and P13 is inherited as a single partially dominant gene. Populations P3 and P40 were 140 and 237-fold more resistant to the PDS inhibitor diflufenican, respectively, than the susceptible populations. Both populations contained a Leu498-Val substitution in the PDS gene. An additional mutation, Glu-425-Asp, was only detected in P40, where cross-resistance to picolinafen was identified. These results suggest that Leu498 mutation alone can confer a high level of resistance to diflufenican; however, the presence of both Leu498 and Glu425 mutations increased the level of resistance to diflufenican and also conferred resistance to picolinafen. Fitness studies conducted under competition with wheat in the absence of herbicides in pots revealed that the mutant PDS genes in populations P3 and P40 did not impose any fitness costs. This means once a resistant trait occurs in the field, it will persist in the absence of herbicides.Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2018
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Myers, Mark Gerard. « Control of triazine resistant common lambsquarters (Chenopodium album L.) and smooth pigweed (Amaranthus hybridus L.) in corn (Zea mays L.) with preemergence, early postemergence and postemergence herbicide applications ». 1989. http://catalog.hathitrust.org/api/volumes/oclc/19731752.html.
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HLÁVKOVÁ, Markéta. « Hodnocení subchronického působení atrazinu na raka (Cherax destructor) ». Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-375942.
Texte intégralRésumé :
The evaluation of the sub-chronic exposure to atrazine on crayfish The aim of this study is to evaluate the sub-chronic effect of atrazin on a behaviour, oxidative stress, antioxidant enzyme aktivities and biochemical profile of haemolymph in. These complex data should help to appraise the impact of this substance in the environment. The total test duration was 28 days and was divided into two periods. The first 14 days the crayfish were exposed to two concentrations of atrazine: 6.86 micrograms per liter (ATRenv = environmental concentration in the water in the Czech Republic) and 1.21 milligrams per liter (ATR10% = is coincident to 10% LC50). After the atrazine treatments the depuration 2 weeks phases in water without any chemicals followed. The results indicate that sub-chronic effect of atrazine influenced neither the behaviour of the crayfish nor the level of oxidative stress (measured by TBARS), whereas the changes of superoxiddismutase (SOD) were observed in all tissues (muscles, gills and hepatopancreas). The changes of enzyme activity were observed in catalase (CAT; hepatopancreas and the muscle tissue), glutathione S-transferase (hepatopancreas and the gills tissue), glutathione reductase (GR; the hepatopancreas tissue) and reduced glutathione (the muscle tissue). The influence of ATRenv on the biochemical profile of haemolymph at the following parameters was estimated only for lactate and alkaline, however phosphatase changes made by ATR10% were significant for glucose, ammonia, lactate and alkaline phosphatase measurements. The sub-chronical effect changed the activity of all antioxidant enzymes in hepatopancreas, muscles and the gills tissue of the observed crayfish. The presented results in this study are giving compact information of impact of atrazine on the crayfish and the whole water environment. The suggestion of using the crayfish for tests of toxicity looks like an ideal supplement for triazine herbicide estimations.
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HUANG, RONG-NAN, et 黃榮南. « Immunoassay of 2-chloro--4,6-diamino-s-triazine(CAAT),the the didealkylated metabolite of chloro-s-triazine herbicides ». Thesis, 1992. http://ndltd.ncl.edu.tw/handle/48702125666331142063.
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Tsai, Cheng-Yuan, et 蔡承遠. « Capillary electrophoresis/electrospray mass spectrometry of priority phenols and triazine herbicides ». Thesis, 1996. http://ndltd.ncl.edu.tw/handle/38564172967588017205.
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Francois, Derek Louis. « An investigation of tolerance to three triazine herbicides in Chlamydomonas geitleri Ettl ». 1988. http://hdl.handle.net/1993/16671.
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Goldsborough, L. Gordon. « Effects of two triazine herbicides on the structure and metabolism of freshwater marsh periphyton ». 1986. http://hdl.handle.net/1993/30016.
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Davenport, Douglas T. « Degradation and sorption of select triazine, analide and carboxylic acid herbicides using zero-valent iron ». 1996. http://catalog.hathitrust.org/api/volumes/oclc/36667078.html.
Texte intégralRésumé :
Thesis (M.S.)--University of Wisconsin--Madison, 1996.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 84-87).
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Hsu, Chou-Yi, et 許朝一. « Analysis of triazine herbicides in aqueous sample based on little solvent with dispersive liquid-liquid microextraction ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/36627809307811437608.
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Liu, Yu-Chih, et 劉宇智. « Studies of Separation and On-line Concentration of s-Triazine Herbicides and Phenothiazines in Capillary Electrophoresis ». Thesis, 2006. http://ndltd.ncl.edu.tw/handle/53769179684066439201.
Texte intégralRésumé :
博士國立臺灣大學
化學研究所
94
Environmental pollutants and pharmaceutical compounds were selected for studying the enhancement of detection sensitivity. In this dissertation, on-line concentration of small molecules on capillary electrophoresis studied is consisting of three parts: In the first part, we focus on the stacking of environmental pollutants, such as methylthio-s-triazines herbicides, in normal stacking mode using sodium dodecyl sulfate (SDS) as an anionic surfactant and borate electrolyte at pH 9.0. The sample matrix used for concentration of neutral analytes is 30 mM borate electrolyte, and the optimal electrophoretic system for separation consists of 20 mM SDS and 20 mM borate buffer at pH 9.0. Interestingly, two maxima were observed in the plot of absorbance versus SDS concentration in the range 10-150 mM. Stacking efficiency of each individual analyte depends on its binding constant to SDS micelles, terbutryn can afford about 1000-fold enhancement under an optimal electrophoretic system. With this stacking mode, the sample solution can be injected up to 180 s, and the limits of detection (S/N=3) of terbutryn, prometryn, ametryn and simetryn determined to be 61, 25, 11 and 2 ng / mL, respectively. In the second part, we focus on the stacking of s-triazines herbicides using sweeping technique. The separation buffer consisting of anionic surfactant and phosphate electrolyte at pH 5.6 was used. The injection time of 480 sec can be achieved for baseline separation of four s-triazines. The concentrations of phosphate buffer at 50 mM was used as the sample matrix, while separation buffer consists of 50 mM phosphate electrolyte and 50 mM SDS containing 20 % methanol at pH 5.6, sample matrix and separation buffer were optimized. With this sweeping mode, the sample solution can be injected up to 480 s, and the limits of detection (S/N=3) of terbutryn, prometryn, ametryn and simetryn determined to be 3.0, 2.0, 1.5 and 1.2 ng / mL, respectively, with UV detection. In the third part, the enantioseparation and stacking of phenothiazine enantiomers based on the pH junction-sweeping mechanism were investigated. Phenothiazine samples were dissolved in water at neutral pH, whereas phosphate buffer at pH 3.0 containing different type of cyclodextrins (CDs), such as randomly sulfated β-CD (S-β-CD), β-CD HP-β-CD, DM-β-CD and γ-CD, was used as separation buffer. γ-CD shows the best enantioresolution for four phenothiazines, including promethazine, ethopropazine, trimeprazine and thioridazine. Effective enantioseparation and stacking of phenothiazine enantiomers could be achieved with the injection time of 1800 sec, when multi-cyclodextrins, such as S-β-CD / β-CD / γ-CD was employed. Due to extremely large injection volume (a filling of 98.9 % effective length), the signal of thioridazine (5a) could be greatly enhanced.
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Liu, Yu-Chih, et 劉宇智. « Separation and On-line Concentration of s-Triazine Herbicides in Micellar Electrokinetic Chromatography Using Cationic Surfactants ». Thesis, 1999. http://ndltd.ncl.edu.tw/handle/75673098205627252260.
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Gurney, Sharon Elizabeth. « Investigations of the effects of two triazine herbicides on periphytic algal communities in the Delta Marsh, Manitoba ». 1988. http://hdl.handle.net/1993/6860.
Texte intégralRésumé :
Triazine herbicides are used in aquatic management primarily to control macrophytes and undesirable phytoplankton populations. Triazines used for terrestrial weed control also enter aquatic systems through runoff, aerial drift or from spillage. This study assesses the impact of two of these triazines, simazine and terbutryn, on the structure, function and biomass of periphytic algae within in-situ littoral enclosures. Secondary effects of treatment on water chemistry were also monitored during an 87 days experimental period. The second half of this study describes an automated quantitative grain density microautoradiography procedure. The effects of Lugol's iodine on isotope leakage from cells preserved for autoradiography, was demonstrated using three haptobenthic diatom species. The applicability of using this technique to evaluate intra and interspecific variation in algal response to triazine exposure in-situ was also discussed.
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Hsueh, Chung-Chuan, et 薛仲娟. « Studies of Migration Behavior and Separation of Chlorophenolsand and s-Triazines Herbicides by Capillary Electrophoresis ». Thesis, 1999. http://ndltd.ncl.edu.tw/handle/55335410080587610824.
Texte intégralRésumé :
博士國立臺灣大學
化學研究所
87
Abstract The influence of buffer pH on the migration behavior and separation of isomeric trichloro-phenols (TCPs) was systematically investigated using capillary zone electrophoresis. Complete separation of isomeric trichlorophenols was achieved with a phosphate-borate buffer in the pH range 5.8~8.0 at 10 kV. The present results confirm that the optimum pH condition is indicated by the change in the shape of curves from concave to convex in the plots of electrophoretic mobilities of trichlorophenols at some given pH (roughly in the range pKa±2)versus the pKa value of each corresponding isomer. At this optimum pH, electrophoretic mobility of isomeric trichlorophenols correlates linearly with their pKa values. The similarity of such correlations in different pH ranges for trichlorophenols and dichlorophenols illustrates the dependence of the electrophoretic mobility of a chlorophenol isomer on both pKa and the molecular size. The pKa values of five isomeric trichlorophenols are reported. The migration behavior and separation of various s-triazines, including five chloro-, three methoxy- and five alkylthio-s-triazines, were investigated in micellar electrokinetic chromatography (MEKC) using a cationic surfactant. In this study, tetradecyltrimethyl ammonium bromide (TTAB) was selected as a cationic surfactant. The results indicate that the selectivity of neutral species of s-triazines in each class is not significantly influenced by buffer pH and micelle concentration, but the overall selectivity is considerably affected by these two separation parameters when charged solutes are present, particularly, at buffer pH below 5.0. Complete separation of thirteen s-triazines was optimally achieved within six minutes on addition of TTAB (15 mM) to a phosphate buffer (70 mM) at pH 4.75 or 3.8. Based on a model that describes the relationship of the effective electrophoretic mobility of a neutral solute and micelle concentration in MEKC, the migration behavior of chloro-s-triazines at pH 6.0 is predicted and the binding constants of s-triazines to TTAB micelles are evaluated. The correlation between the binding constants and Pow (the partition coefficient of a solute between 1-octanol and water) reveals that the migration order of s-triazines in each class is primarily determined by the hydrophobicity of the solutes.
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Chen, Yet-Ran, et 陳逸然. « Analysis of triazine herbicides and huna-lian by capillary electrophoresis sequential mass spectrometer. Unknown peaks caused by adding the cyclodextrin to the running buffer ». Thesis, 1998. http://ndltd.ncl.edu.tw/handle/94479415344418570517.
Texte intégralRésumé :
碩士國立臺灣大學
化學系研究所
86
Capillary Electrophoresis (CE) in combination with sequential mass spectrometr y such as MS/MS/MS, proved to be an ideal technique to the analysis of complex mixtures. Triazine herbicides and Chinese medicine fortified with coptisine, palmatine, berberine HCl were studied by CE/MSn. The result showed that more reliable identification could be achieved in comparison with CE/MS.In the ana lysis of ganglioside mixture by CE/UV, peaks not related to gangliosides were observed. The intensities of these peaks were found to be inverse proportiona l to the concentration of alpha- beta- gamma- CDs in sample zone; negative peaks were observed when the CD concentrations in sample zone were larger tha n the buffer zone. Due to the concentrations of hydroxide ion, absorbance at 200nm increased as buffer pH increased. It is found that hydroxide ion has higher absorptivity then neutral CDs. This observation leads to the speculati on that CD peaks, whether they are positive or negative, are resulting from th e replacement of hydroxide ion with CDs.
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Lin, Yung-Hua, et 林詠樺. « New Graphene/Acrylic resin based Composite Sponge Material as Solid Phase Extraction Sorbent for the Determination of Triazine Herbicides in Aqueous sample by HPLC-UV ». Thesis, 2016. http://ndltd.ncl.edu.tw/handle/67091200849791713102.
Texte intégralRésumé :
碩士國立中興大學
化學系所
104
In this study, we have developed a new material ‘Graphene based acrylic resin composite sponge material’ as sold phase extraction sorbent material for the extraction of triazine herbicides in aqueous solution and determination by HPLC-UV. The adsorption capacity of acrylic resin material was enhanced by adding graphene nanosheets as fillers. This composite sponge material was prepared by mixing of graphene oxide, acrylic resin, cross-linking agents and foaming agents and then inflated with air to foam by Frother. And the foam material was heated at two stages to obtain Graphene/Acrylic resin based Composite Sponge Material. In the extraction procedure, the sponge material was placed into the syringe and sample solution was aspirated into the syringe barrel for rapid adsorption/extraction. Then the adsorbed analytes were desorbed using organic solvent, and dried by nitrogen, then re-dissolved with 100 μL acetonitrile for HPLC-UV analysis. In order to obtain the best extraction efficiency, the parameters affecting the conditions including graphene content, the pH of sample solution, the salt addition and desorption solution were investigated thoroughly. Under the selected conditions, composite sponge materials were synthesized with 15 mg of graphene and 1 mL acrylic resin solution. 10 mL of aqueous solution (pH 7) was used for sample loading and followed with elution using 3 mL acetone. Under the optimal conditions, the limit of determination (LOD) and limit of quantitation (LOQ) for five triazine herbicides were between 0.3 ng/mL and 0.9 ng/mL. The relative standard deviations (RSD) were less than 3%. Recoveries were ranged between 82.8 % - 107 %. The total sample preparation steps were taken only 10 minutes. These results indicated that the Graphene/Acrylic resin Composite Sponge Material based solid phase extraction method is a rapid, sensitive, easy to handle and eco-friendly sample preparation method.