Profenofós é um organofosforado empregado como inseticida e acaricida amplamente utilizado no Brasil para o controle de pragas de cebolas, milho, soja, café, tomate, algodão, feijão, batata e outros. A irradiação é um processo empregado em todo o mundo e recomendada por diversos órgãos de saúde para a conservação de alimentos. A radiação ionizante utiliza raios gama, raios X ou aceleradores de elétrons e tem sido aplicada para eliminar ou reduzir a ação de agentes patogênicos e contribuir para aumentar o tempo de estocagem de vários alimentos. Os objetivos desse trabalho foram: (a) avaliar a degradação de soluções aquosas de profenofós submetidas à radiação ionizante, identificar e quantificar a formação de novos produtos por GC-MS; (b) analisar o efeito de feixe de elétrons em ervilhas inoculadas com soluções aquosas de profenofós; (c) sintetizar Polímeros Molecularmente Impressos (MIP) e Sílica Impressa Molecularmente (MIS), posteriormente, caracterizar os adsorventes em fase sólida e verificar sua seletividade para profenofós. O tratamento com aceleradores de elétrons com dose 31,6 kGy promoveu a formação de um novo produto de degradação e redução de 93,40 % de profenofós em soluções aquosas. Em ervilhas inoculadas com 1 μg de profenofós submetidas à radiação ionizante de 30,4 kGy promoveu uma redução na concentração de profenofós em 57,46 %. Além disso, foram realizadas sínteses de MIP e MIS para a extração em fase sólida de profenofós. Os MIS sintetizados por sol-gel mostraram-se eficazes para o reconhecimento molecular e extração seletiva de profenofós. / Profenofos is an organophosphate widely used in Brazil as insecticide and acaricide in the control of pests in onions, corn, soybeans, coffee, tomato, cotton, beans, potatoes among others. Irradiation is a process used worldwide and recommended by many health agencies for food preservation. Food irradiation preserving process uses accelerated electrons, gamma rays or X-rays. Ionizing radiation treatment is applied to eliminate or to reduce the action of pathogens and to increase the shelf life of some foods. The objective of this study were (a) to evaluate the degradation of aqueous solutions of Profenofos by ionizing radiation, identify and quantify the formation of new products by GC-MS; (b) to analyze the effects of electron beam in peas inoculated with aqueous solutions of Profenofos; (c) to synthesize Molecularly Imprinted Polymer (MIP) and Molecularly Imprinted Silica (MIS), subsequently characterize the adsorbents in solid phase and check its selectivity for profenofos. The treatment with electron accelerators with 31.6 kGy dose promoted the formation of a new by-product and 93.40 % reduction of profenofos in aqueous solutions. In peas inoculated with 1 μg of profenofos by ionizing radiation of 30.4 kGy promoted a reduction of 57.46 % in the concentration of profenofos. Furthermore, the MIP and MIS were performed for solid phase extraction of profenofos. The MIS synthesized by sol-gel proved to be effective for the recognition molecular and selective extraction of profenofos.

In recent years, the indiscriminate use of pesticides and a lack of adoption of good agricultural practices have been evidenced by the results of analyzes of residues of pesticides in food. Thus, the goal of this work was to develop and validate two methods for determination of pesticide residues in plum, apple, pear and peach, with analysis by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). In the development of the QuEChERS method, different conditions of the extract clean-up were tested. In the validation results, the linear range of the method was 5 to 200 μg kg-1 with recoveries were between 70 and 120% and RSD ≤20%. The practical limit of quantification (LOQ) for 161 compounds was 10 μg kg-1. In MSPD optimization, different sorbents (C18, florisil®, PSA, alumina, amino, silica, chitosan, Oasis® HLB, StrataTM-X and fluoridated) were tested as solid support in different proportions with the sample. The homogenization was carried out with metallic spheres and extraction with acetonitrile and ultrasound. Accuracy and precision results obtained by MSPD were adequate for 131 pesticides residues studied, with recovery results ranging between 70 and 120%, with RSD ≤ 20%. The studied compounds presented practical LOQ of 10 μg kg-1. In the analysis of 100 samples of the studied fruits, different pesticides residues were found in concentrations ranging from <LOQ to 2.334,6 μg kg-1. / Nos últimos anos, o uso indiscriminado de agrotóxicos e a não adoção das boas práticas agrícolas têm sido evidenciados pelos resultados de análises de resíduos de agrotóxicos em alimentos. Assim, este trabalho teve como objetivo desenvolver e validar dois métodos para determinação de resíduos de agrotóxicos em ameixa, maçã, pera e pêssego, com análise por cromatografia líquida de ultra eficiência acoplada à espectrometria de massas em série (UHPLC-MS/MS). No desenvolvimento do método QuEChERS, diferentes condições da limpeza do extrato foram testadas. Nos resultados de validação, o intervalo linear do método foi de 5 a 200 μg kg-1, com recuperações entre 70 e 120% e RSD ≤ 20%. O limite de quantificação prático (LOQ) para 161 compostos foi de 10 μg kg-1. No desenvolvimento da técnica MSPD foram testados diferentes sorventes (C18, florisil®, PSA, alumina, amino, sílica, quitosana, Oasis® HLB, StrataTM-X e fase fluorada) como suporte sólido em diferentes proporções com a amostra. A homogeneização foi realizada com auxílio de esferas metálicas e a extração com acetonitrila e ultrassom. Os resultados de exatidão e precisão obtidos por MSPD foram adequados para resíduos de 131 agrotóxicos, com resultados de recuperação entre 70 e 120%, with RSD ≤ 20%. Os compostos estudados apresentaram LOQ prático de 10 μg kg-1. Na análise de 100 amostras das frutas estudadas, foram quantificados resíduos de diferentes agrotóxicos em concentrações entre <LOQ e 2.334,6 μg kg-1.

L’utilisation intensive de certains pesticides et leur relative persistance vont de pair avec la présence de résidus dans l’eau de surface et l’eau potable mais aussi dans les produits agricoles disponibles pour les consommateurs, y compris les denrées alimentaires. À l’heure actuelle, les effets des pesticides sur la vie aquatique et d’autres organismes non ciblés sont relativement bien connus, et la possibilité des effets sur l’être humain fait débat. Des normes de qualité ont été proposées pour l’eau, que ce soit des critères pour l’eau potable ou des critères de protection de la vie aquatique pour l’eau de surface. Des limites maximales de résidus (MRL) de pesticides ont également été établies pour certains produits, notamment les fruits et légumes. Un des défis pour les chercheurs est la mise en œuvre de nouvelles méthodes analytiques sensibles et robustes pour la quantification ultra-trace de ces composés, afin de déterminer si les différents échantillons sont conformes aux directives ou aux MRL. L’analyse des pesticides modérément polaires dans des matrices complexes repose tout d’abord sur la méthode d’extraction. Plusieurs options sont disponibles, telles que l’extraction liquide-liquide ou en phase solide (SPE, Solid Phase Extraction) pour les matrices aqueuses, ou encore dSPE de type QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) pour les matrices solides. Actuellement, la chromatographie en phase liquide couplée à la spectrométrie de masse en tandem représente un choix pertinent pour les analyses ultra-traces, mais sa mise en œuvre peut présenter certains défis. Dans ce contexte, les principaux objectifs de ce travail de recherche sont les suivants : i) proposer des méthodes analytiques rapides, sensibles et robustes pour déterminer des pesticides multi-classes aux niveaux d’exposition que l’on retrouve dans différentes matrices comme l’eau potable, les denrées alimentaires et l’urine comme matrice biologique, et ii) évaluer le lien entre les sources de contamination des divers pesticides et leur mobilité afin de documenter la distribution spatiale et temporelle dans l’eau de surface et l’eau potable au Québec. Pour les échantillons aqueux, une méthode SPE en ligne entièrement automatisée couplée à la chromatographie liquide haute performance et spectrométrie de masse en tandem a été développée. La méthode proposée est rapide (8 min par échantillon) avec des limites de détection comprises entre 0.1 et 5 ng L-1 pour les pesticides de la famille des néonicotinoïdes et l’atrazine. Pour les produits alimentaires tels que les fruits et légumes, l’optimisation d’une méthode de type QuEChERS a été réalisée. La méthode permet d’atteindre des niveaux de détection entre 0.05 ng g-1 et 2 ng g-1 pour une gamme de 22 pesticides couvrant 7 classes différentes, incluant les organophosphorés, les carbamates, les néonicotinoïdes et les triazines, entre autres. La robustesse des diverses méthodes a été démontrée par des expériences de contrôle qualité inter- et intra-journaliers afin de garantir l’exactitude, la précision et l’absence d'effets matriciels pour de longues séquences d’analyse. Les méthodes validées ont été appliquées à des échantillons réels, y compris des échantillons d’eau du robinet couvrant 52 villes de la province du Québec (Canada), 68 échantillons d’eau de surface (fleuve Saint-Laurent et tributaires), et 133 échantillons de laitue, pomme, raisin et tomates achetés sur les marchés locaux. Les résultats indiquent une forte occurrence de l’atrazine, la thiaméthoxame, la clothianidine et l’imidaclopride dans les échantillons d’eau et les quatre produits alimentaires. / The extensive use of certain pesticides and their relative persistence go on par with the presence of residue levels in surface water and drinking water, but also in agricultural products available to consumers (including foodstuffs). There are potential effects on aquatic life and non-target organisms, and the possibility of effects in humans remains a topical issue. Quality standards have been proposed for water, including criteria for drinking water and criteria for the protection of aquatic life (surface water). Maximum residue limits (MRLs) for pesticides have also been established for foodstuff, including fruits and vegetables. One of the challenges for researchers is the implementation of sensitive and robust analytical methods for the ultra-trace quantification of these compounds, with a view to determining whether the samples are compliant with guidelines or MRLs. The analysis of moderately polar pesticides in complex matrices relies notably on the extraction method. Diverse options are available, including liquid-liquid or solid phase extraction (SPE) for aqueous samples, and dSPE approaches such as QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) for solid samples. Liquid chromatography coupled to tandem mass spectrometry is usually selected for separation and detection at the ultra-trace level, but there are some pitfalls. In this context, the main objectives of the present research were as follows: i) to propose fast and robust analytical methods to determine multi-class pesticides at different exposure routes including drinking water and food, and ii) to evaluate the link between the contamination sources of various pesticides and their mobility to document their distribution in surface water and tap water in Quebec. For water samples, a fully automated on-line SPE method coupled to ultra-highperformance liquid chromatography tandem mass spectrometry was developed. The proposed method is rapid (8 min per sample) with detection limits between 0.1 and 5 ng L- 1 for neonicotinoids and atrazine. For food products (fruits and vegetables), a QuEChERS method was investigated. The optimized procedure shows limits of detection between 0.05 ng g-1 and 2 ng g-1 for a total of 22 pesticides encompassing 7 different classes, including organophosphorus compounds, carbamates, neonicotinoids and triazines, among others. The robustness of the various methods has been demonstrated by inter-day and intra-day iv quality control experiments to ensure suitable accuracy, precision, and the absence of matrix effects in long LC-MS batch sequences. The validated methods were applied to real samples, including tap water samples from 52 municipalities in the province of Quebec (Canada), 68 surface water samples from the St. Lawrence River and its main tributaries, and 133 fruits and vegetables samples (lettuce samples, apples, grapes and tomatoes) purchased from local markets. The results indicate a high occurrence of atrazine, thiamethoxam, clothianidin, and imidacloprid in the water samples and the four food products.

Thesis are aimed to the optimization and validation of the QuEChERS method for determination of polycyclic aromatic hydrocarbons in solid matrices of hydrosphere. The QuEChERS method was also used for determination of polycyclic aromatic hydrocarbons in real samples and for comparison of measured results, time and material costs of the method with currently employed methods: (1) accelerated solvent extraction connected with gel permeation chromatography (ASE/GPC), and (2) ultrasonic extraction connected with solid phase extraction (UZ/SPE). According to the validation criteria, the QuEChERS method is suitable for the determination of polycyclic aromatic hydrocarbons in solid matrices of hydrosphere. The QuEChERS technique provides comparable results to ASE/GPC and UZ/SPE. In terms of price and time for sample preparation, the QuEChERS method allows (unlike the methods ASE/GPC and UZ/SPE) fast and inexpensive determination of polycyclic aromatic hydrocarbons in solid samples of hydrosphere.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The rice is the main component of the basic diet of the world-wide population, is therefore, of extreme importance for the food security. In function of this, related aspects its production and comsumption must continuously be monitored and be evaluated, so that its supply is guaranteed. In this study, was development and validated a methodology for determination of residues of 51 pesticides in polish rice grains, using the modified QuEChERS extraction method and Gas Chromatography coupled to Mass Spectrometry with Negative Chemical Ionization and Selected Ion Monitoring (GC-MS NCI-SIM). To that end, previous homogenized rice was spiked with 51 pesticides at 3 different spiking levels (10, 20 and 50 μg kg-1, 6 replicates at each level) and extracted by the modified QuEChERS method. Applying this method, 10 mL of acetonitrile was added to 10.0 g of rice matrix and the tubes were vigorously shaken by hand for 45 s. The tubes were uncapped, 3.0 g of anhydrous magnesium sulfate and 1.7 g of sodium acetate were added, the shaking procedure was repeated and the extract was centrifuged for 8 min. Furthermore, a dispersive clean-up was developed for extract purification. The upper layer (4 mL) of the extracts was transferred to another tube containing 600 mg of anhydrous magnesium sulfate and 500 mg of C18, the shaking procedure was repeated and the extract was centrifuged for 8 min. The extracts were analized by GC-MS NCI-SIM. The method validation was performed of the linear range of the analytical curves (7 concentration levels and 6 injections each), detection limit (LOD), quantification limit (LOQ), matrix effect, as well as precision (as RSD%) and accuracy (as recovery percent). In general, LOD, LOQ and r2 results, obtained from GC, were affected by standards prepared in matrix extract compared to the preparation in solvent. The linear calibration curves was between 1.0 or 2.0 to 100.0 ng mL-1 with r2 values ≥ 0,99. The GC-MS (NCI) allowing the quantification (recovery criteria 70-120% and RSD% values ≤ 20%) of 87% of the target compounds, that showed LOQm of 10 or 20 mg kg-1. Hence, it is possible to conclude, this method proved to be adequate for the multi-residue analysis of pesticides in rice, conciliating sensitivity and acceptable selectivity and all the validation parameters were within the limits suggested for validation of chromatographic methods. / O arroz é o principal componente da dieta básica da população mundial. É, portanto, de extrema importância para a segurança alimentar e, em função disso, aspectos relacionados à sua produção e consumo devem ser continuamentemonitorados e avaliados em profundidade, para que o seu suprimento seja garantido. Neste estudo, foi desenvolvida e validada uma metodologia para a determinação, em grãos de arroz polido, de resíduos de 51 pesticidas, analisados utilizando o método de extração QuEChERS modificado e Cromatografia Gasosa com Detecção por Espectrometria de Massas, operando no modo de Ionização Química Negativa e Monitoramento do Ion Selecionado (GC-MS NCI-SIM). Para isso, realizou-se a fortificação do arroz, previamente homogeinizado, com soluções contendo os 51 pesticidas, em 3 níveis de fortificação (10, 20 e 50 μg kg-1), 6 réplicas para cada nível, e aplicou-se o método QueChERS modificado. A extração por este método consistiu na pesagem de 10,0 g da matriz, adição de 10 mL de acetonitrila e procedeu-se a agitação manual e vigorosa, por cerca de 45 segundos. Acrescentou-se 3,0 g de sulfato de magnésio anidro e 1,7 g de acetato de sódio anidro, repetindo-se agitação. Foram, posteriormente, centrifugados por 8 minutos A purificação dos extratos foi realizada através de clean-up dispersivo, onde 4 mL do extrato foram transferidos para outro tubo já contendo 600 mg de sulfato de magnésio anidro e 500 mg de C18, repetindo-se a agitação e a centrifugação, e em seguida os extratos foram analisados por GC-MS NCI-SIM. Neste trabalho avaliouse os seguintes parâmetros de validação do método: faixa de linearidade das curvas analíticas (7 níveis de concentração e seis injeções cada), limite de detecção (LOD), limite de quantificação (LOQ), efeito matriz, bem como a precisão e a exatidão (em termos de percentual de recuperação). Em geral, os valores de LOD, LOQ e r2, obtidos por GC, foram influenciados pela utilização de extratos da matriz para o preparo das soluções analíticas. A faixa linear de concentração das curvas analíticas situou-se entre 1,0 ou 2,0 a 100,0 ng mL-1 com valores de r2 ≥ 0,99. A técnica GCMS NCI modo SIM promoveu a quantificação (critérios de recuperação entre 70 e 120% e valores de RSD% ≤ 20%) de 87% dos compostos que apresentaram LOQm de 10 ou 20 mg kg-1. Portanto, conclui-se que o método mostrou-se adequado à análise multirresíduo dos pesticidas em arroz, conciliando sensibilidade e seletividade adequadas, e todos os parâmetros de validação encontram-se dentro dos limites sugeridos para validação de métodos cromatográficos.

<p>Insekticidi novije generacije, neonikotinoidi, odlikuju se specifičnim načinom &nbsp;delovanja na&nbsp;nervni sistem insekata. Radi dobijanja &scaron;to brže i kvalitetnije informacije o izloženosti životne sredine&nbsp;ovim insekticidima i količinama njihovih ostataka u hrani potrebno je raspolagati odgovarajućim&nbsp;instrumentalnim metodama za njihovo određivanje. Razvijene su i optimizovane analitičke metode&nbsp;zasnovane na tečnoj hromatografiji za određivanje sedam odabranih neonikotinoida (dinotefurana,&nbsp;nitenpirama, tiametoksama, klotianidina, imidakloprida, acetamiprida &nbsp;i tiakloprida) u medu i likeru od&nbsp;meda. Ispitivana je mogućnost određivanja klotianidina pomoću tečne hromatografije visoke efikasnosti&nbsp;sa detektrorom od niza dioda (HPLC-DAD) primenom kombinacije tečno-tečne i ekstrakcije na čvrstoj&nbsp;fazi iz uzoraka meda. Na osnovu preliminarnih rezultata može se zaključiti da kori&scaron;ćenje &nbsp;faznih-čvrsto&nbsp;kolona u kombinaciji sa tečno-tečnom ekstrakcijom dihlormetanom rezultira prihvatljivim prinosom&nbsp;klotianidina u uzorcima meda pri koncentraciji od oko 0,5 &micro;g g^-1&nbsp;klotianidina. Radi dobijanja većih&nbsp;prinosa odabrana je disperzna tečno-tečna mikroekstrakcija (DLLME) kao tehnika pripreme uzoraka&nbsp;meda. Testirana je upotreba acetonitrila kao disperznog sredstva. Pored hloroforma, kori&scaron;ćen je i&nbsp;dihlormetan kao drugo ekstrakciono sredstvo, kako bi se &nbsp;uporedila efikasnost ekstrakcije. Zabeleženi su&nbsp;prinosi klotianidina od 69,7 i 68,3% &nbsp;u zavisnosti da li je kori&scaron;ćen hloroform, odnosno DHM kao rastvor&nbsp;za ekstrakciju. Može se zaključiti da je prinos ekstrakcije bio povoljniji pri odnosu 0,5 mL ACN i 2,0&nbsp;mL DHM. Prinosi su se kretali od 68,4% do 92,1%, &scaron;to je ukazalo da su parametri DLLME ekstrakcije optimalni. Kako bi se detaljnije ispitali ključni parametri DLLME tehnike, kori&scaron;ćena je metodologija povr&scaron;ine odziva (RSM), kao i detekcija na osetljivijem kuplovanom masenom detektoru (MS/MS). Optimizovani su HPLC-MS/MS &nbsp;parametri kako bi se obezbedilo zadovoljavajuće hromatografsko &nbsp;razdvajanje i niske granice detekcije (GD, 0,5&ndash;1,0 &mu;g kg^-1) i određivanja (GO, 1,0&ndash;2,5 &mu;g kg^-1) ispitivanih neonikotinoida u medu. Upotrebom centralno kompozitnog dizajna konstruisani su kvadratni modeli ispitivanih faktora: zapremine ekstrakcionog (DHM, 1,0&ndash;3,0 mL) i disperznog (ACN, 0,0&ndash;1,0 mL) sredstva, izračunati statistički parametri i optimizovan proces DLLME upotrebom <em>Derringer</em>-ove funkcije poželjnih odgovora. Upotrebom MMC i SC krivih u opsegu GO&ndash;100,0 &mu;g kg^-1&nbsp;ispitan je uticaj matriksa pri čemu zaključeno je da je najveći uticaj matriksa bio na odziv analitičkog signala nitenpirama, dinotefurana i klotianidina. Ispitani su prinosi odabranih neonikotinoida (R, 74,3&ndash;113,9%), kao i preciznost metode u uslovima ponovljivosti (RSD, 2,74&ndash; 11,8%) i intermedijerne reproduktivnosti (RSD, 6,64&ndash;16,2%). Brza (retenciona vremena 1,5&ndash;9,9 min) i osetljiva metoda, koja tro&scaron;i malu količinu rastvarača, primenjena je za ispitivanje 15 realnih uzoraka meda različitog cvetnog porekla. Rezultati su pokazali da ispitivani med nije sadržao ostatke ispitivanih neonikotinoida u koncentracijama iznad GD. Dalje istraživanje je bilo usmereno ka&nbsp; razvijanju i optimizaciji HPLC-DAD analitičke metode upotrebom DLLME i QuEChERS tehnika za &nbsp;pripremu uzoraka za određivanje 7 neonikotinoida u uzorcima meda. U ovom delu istraživanja optimizovani su i hromatografski parametri, upotrebom RSM sa Box-Behnken-ovim dizajnom i Derringer-ovom funkcijom poželjnih odgovora. Od &nbsp;ispitivanih neonikotinoida dinotefuran i imidakloprid su bili u najvećoj meri izloženi uticaju matriksa, bez obzira na proceduru pripreme uzoraka. Može se istaći da je uticaj matriksa na analitički signal dinotefurana bio izraženiji u slučaju MS/MS, apostrofirajući manju robusnost ove metode određivanja. Prinosi neonikotinoida su &nbsp;bili (R, 73,1&ndash;118,3%), preciznost u uslovima ponovljivosti (RSD, 3,28&ndash;10,40%) i intermedijerne reproduktivnosti (RSD, 6,45&ndash;17,70%), a granice detekcije (GD, 1,5&ndash;2,5 &micro;g kg^-1) i određivanja (GO, 5,0&ndash;10,0 &micro;g kg^-1). Metoda je primenjena za ispitivanje 7 neonikotinoida u 104 uzorkameda različitog cvetnog porekla sa &nbsp;teritorije Autonomne Pokrajine Vojvodine. Detektovano je prisustvo tiakloprida, imidakloprida i tiametoksama u količinama koje su bile ispod MDK RS i EU. Analizirani su uzorci likera od meda - medice. Upoređivane su dve tehnike pripreme uzoraka, DLLME i QuEChERS i primenjeni optimizovani hromatografski &nbsp;uslovi i MS/MS parametri. U slučaju nitenpirama, dinotefurana i tiametoksama uticaj matriksa bio je najizraženiji. Metoda je validovana određivanjem prinosa neonikotinoida (R, 69,2&ndash;113,4%), preciznosti u uslovima ponovljivosti (RSD, 3,21&ndash;12,81%) i intermedijerne reproduktivnosti (RSD, 9,11&ndash;16,63%), kao i granice detekcije (GD, 0,5&ndash;2,5 &micro;g kg^-1) i određivanja (GO, 1,0&ndash;10,0 &micro;g kg^-1). Analizom 10 komercijalno dostupnih likera od meda otkriveno je&nbsp;prisustvo klotianidina i tiakloprida, evčzokinot&scaron; z&nbsp; na neophodnost daljeg kontrolisanja ovog proizvoda na&nbsp;prisustvo neonikotinoida. Ispitana je mogućnost uklanjanja odabranih neonikotinoida (dinotefurana,&nbsp;klotianidina i tiakloprida) iz vodene sredine (reke Dunav). Ispitivanje efikasnosti 6 različitih vrsta&nbsp;uklanjanja odabranih neonikotinoida (u prisustvu prirodne insolacije u laboratorijskim uslovima, sa&nbsp;dodatkom H2O2, sa dodatkom MWCNT, sa dodatkom MWCN+H&nbsp;₂O₂, sa dodatkom Fe-MWCNT, sa dodatkom Fe-MWCNT+H₂O₂) vr&scaron;eno je upotrebom prethodno razvijene HPLC-MS/MS metode. Krive uklanjanja odabranih neonikotinoida, pokazale su da tokom 60 minuta pri prirodnoj insolaciji&nbsp; u laboratorijskim uslovima koncentracija smanjenje oko 25%. Analitički signal dinotefurana dobijen u prisustvu H₂O_2&nbsp;pod istim uslovima ukazuje na uklanjanje ciljnog analita od oko 40%, tiakloprida od oko 70%, a klotianidina u potpunosti. Testirana je adsorpcija ciljnog analita na vi&scaron;ezidnim ugljeničnim nanocevima (MWCNT). Ovim postupkom može da se ukloni oko 30% dinotefurana, oko 50% klotianidina i 60% tiakloprida. U kombinaciji sa H₂O_2&nbsp;, MWCNT pokazuju bolju sposobnost uklanjanja za 15&ndash;50% u zavisnosti od ispitivanog neonikotinoida. Upotreba Fe-MWCNT i njihova kombinacija sa H₂O₂ otvorila je mogućnost za dalja &nbsp;ispitivanja mehanizma uklanjanja. Ustanovljeno je nastajanje intermedijera kojima odgovaraju m/z od 117,5 i 140,6 u slučaju razgradnje dinotefurana u sistemima sa H₂O₂, MWCNT+H₂O₂, Fe-MWCNT+H₂O_2&nbsp;i klotianidina u sistemu Fe-MWCNT+H₂O₂.</p> / <p>Neonicotinoid insecticides, as one of the fastest growing new generation of insecticides, have&nbsp;contributed to a significant reduction of toxicity for the environment; therefore, monitoring and&nbsp;determination of trace levels of the neonicotinoids in honey are necessary and demands highly efficient,&nbsp;selective and sensitive analytical techniques. The objective of the present work was to develop a rapid,&nbsp;sensitive, optimized and accurate analytical method based on liquid chromatography for determining&nbsp;seven neonicotinoid insecticides, dinotefuran, nitenpyram, thiamethoxam, clothianidin, imidacloprid,&nbsp;acetamiprid and thiacloprid in honey and honey liqueur samples. The possibility for determination of&nbsp;clothianidin in honey samples was investigated by HPLC with a diode array detector (HPLC-DAD).&nbsp;Based on preliminary results, it can be concluded that the use of a solid-phase column in combination&nbsp;with a liquid-liquid extraction with dichloromethane results in an acceptable recovery of clothianidin in&nbsp;the samples with a clothianidin concentration of about 0.5 &micro;g g^-1. After obtaining low recovery of&nbsp;clothianidin, dispersed liquid-liquid microextraction (DLLME) was selected as a technique for the&nbsp;preparation of honey samples.. The adequacy of acetonitrile as a dispersing agent was investigated.&nbsp;Besides the chloroform, a dichloromethane was used as a second extracting agent , in order to compare&nbsp;the relative efficiency of the extraction solvents. It can be concluded that the extraction recovery (68.4&ndash;92.1%) was more favorable with the use of 0.5 mL ACN and 2.0 mL DHM. Furthermore, LC-MS/MS&nbsp;parameters were optimized to unequivocally provide good chromatographic separation, low detection&nbsp;(LOD, 0.5&ndash;1.0 &mu;g L^&minus;1) and quantification (LOQ, 1.0&ndash;2.5 &mu;g L^&minus;1) limits for acetamiprid, clothianidin,&nbsp;thiamethoxam, imidacloprid, dinotefuran, thiacloprid and nitenpyram in honey samples. Using different&nbsp;<br />types (chloroform, dichloromethane) and volumes of extraction (1.0&ndash;3.0 mL) and dispersive&nbsp;(acetonitrile; 0.0&ndash;1.0 mL) solvent and by mathematical modeling it was possible to establish the optimal&nbsp;sample preparation procedure. Matrix-matched calibration and blank honey sample spiked in the&nbsp;<span style="font-size: 12px;">concentration range of LOQ&ndash;100.0 &mu;g kg</span>^{<span style="font-size: 12px;">&minus;1&nbsp;</span>}<span style="font-size: 12px;">were used to compensate the matrix effect and to fulfill the&nbsp;</span><span style="font-size: 12px;">requirements of SANCO/12495/2011 for the accuracy (R 74.3&ndash;113.9%) and precision (expressed in&nbsp;</span><span style="font-size: 12px;">terms of repeatability (RSD 2.74&ndash;11.8%) and within-laboratory reproducibility (RSDs &nbsp;6.64&ndash;16.2%)) of&nbsp;</span><span style="font-size: 12px;">the proposed method. The rapid (retention times 1.5&ndash;9.9 min), sensitive and low solvent consumption&nbsp;</span><span style="font-size: 12px;">procedure described in this work provides reliable, simultaneous, and quantitative method applicable for&nbsp;</span><span style="font-size: 12px;">the routine laboratory analysis of seven neonicotinoid residues in 15 real honey samples. Neonicotinoid &nbsp;</span><span style="font-size: 12px;">residues were not detected in any of the investigated samples. The objective of next study was to&nbsp;</span><span style="font-size: 12px;">develop and optimize HPLC-DAD analytical method with dispersive liquid-liquid microextraction&nbsp;</span><span style="font-size: 12px;">(DLLME) and QuEChERS sample preparation procedures for the simultaneously analysis of seven&nbsp;</span><span style="font-size: 12px;">neonicotinoids in honey samples. The liquid chromatographic conditions were optimized by response&nbsp;</span><span style="font-size: 12px;">surface methodology with <em>Box-Behnken</em> design and the global <em>Derringer</em>&acute;s desirability. The optimized&nbsp;</span><span style="font-size: 12px;">method was &nbsp;validated to fulfill the requirements of SANCO/12495/2011 standard for both sample&nbsp;</span><span style="font-size: 12px;">pretreatment procedures providing results for accuracy (R, 73.1&ndash;118.3%), repeatability (RSD, 3.28&ndash;</span><span style="font-size: 12px;">10.40%) and within-laboratory reproducibility (RSD, 6.45&ndash;17.70%), limits of detection (LOD, 1.5&ndash;2.5&nbsp;</span><span style="font-size: 12px;">g&micro; kg</span>^{<span style="font-size: 12px;">-1</span>}<span style="font-size: 12px;">) and quantification (LOQ, 5.0&ndash;10.0 &micro;g kg</span>^{<span style="font-size: 12px;">-1</span>}<span style="font-size: 12px;">). For the first time, more than 100 honey samples&nbsp;</span><span style="font-size: 12px;">collected from all 7 counties of Autonomous Province of Vojvodina were analyzed. The presence of&nbsp;</span><span style="font-size: 12px;">thiacloprid, imidacloprid and thiametoxam was discovered in a small number of samples. The objective&nbsp;</span><span style="font-size: 12px;">of next study was to develop an optimized LC-MS/MS analytical method with DLLME and QuEChERS&nbsp;</span><span style="font-size: 12px;">procedures for analysis of 7 neonicotinoids in honey liqueur. The method was validated to fulfill the&nbsp;</span><span style="font-size: 12px;">requirements of SANCO/12495/2011 for both sample pretreatment procedures providing results for&nbsp;</span><span style="font-size: 12px;">accuracy (R, 69.2&ndash;113.4% for DLLME; 71.8&ndash;94.9% for QuEChERS), precision (RSD expressed in&nbsp;</span><span style="font-size: 12px;">terms of repeatability (3.21&ndash;10.20% for DLLME; 4.19&ndash;12.81% for QuEChERS) and within-laboratory&nbsp;</span><span style="font-size: 12px;">reproducibility (9.11&ndash;16.63% for DLLME; 11.32&ndash;16.40% for QuEChERS)), limits of detection (LOD,&nbsp;</span><span style="font-size: 12px;">0.5&ndash;1.5 g&micro; L</span>^{<span style="font-size: 12px;">-1&nbsp;</span>}<span style="font-size: 12px;">for DLLME; 1.0&ndash;2.5 g&micro; L</span>^{<span style="font-size: 12px;">-1&nbsp;</span>}<span style="font-size: 12px;">for QuEChERS) and quantification (LOQ, 1.0&ndash;5.0 g&micro; L</span>^{<span style="font-size: 12px;">-1&nbsp;</span>}<span style="font-size: 12px;">for&nbsp;</span><span style="font-size: 12px;">DLLME; 2.5&ndash;10.0 &micro;g L</span>^{<span style="font-size: 12px;">-1&nbsp;</span>}<span style="font-size: 12px;">for QuEChERS). Analysis of real honey liqueur samples obtained from local&nbsp;</span><span style="font-size: 12px;">markets showed the presence of clothianidin or thiacloprid in four of the analyzed samples, therefore&nbsp;</span><span style="font-size: 12px;">implicating the necessity of ongoing control of this type of traditional product. &nbsp;Removal of selected&nbsp;</span><span style="font-size: 12px;">neonicitinoid insecticides - dinotefuran, clothianidin and thiacloprid using MWCNT and H</span><span style="font-size: 12px;">₂O_2&nbsp;</span><span style="font-size: 12px;">from&nbsp;</span><span style="font-size: 12px;">Danube water matrix was investigated. &nbsp;Efficiency of different systems for neonicotinoids removal&nbsp;</span><span style="font-size: 12px;">(under natural insolation in laboratory, with H</span><span style="font-size: 12px;">₂O₂, with MWCNT, with MWCNT+ H</span><span style="font-size: 12px;">₂O₂, with Fe-MWCNT, with Fe-MWCNT+H₂O₂) was evaluated with developed LC-MS/MS method. Analysis of&nbsp;</span><span style="font-size: 12px;">degradation rates revealed loss of 25% of the initial neonicotinoid concentration under natural insolation in&nbsp;</span><span style="font-size: 12px;">the laboratory conditions during 60 min. Addition of chemical agent H₂O_2&nbsp;promoted loss of 40% of the&nbsp;</span><span style="font-size: 12px;">initial dinotefuran, 70% of thiacloprid concentration and total removal of clothianidin under same&nbsp;</span><span style="font-size: 12px;">conditions. With the addition &nbsp;of MWCNT concentration of dinotefuran, clothianidin and thiacloprid&nbsp;</span><span style="font-size: 12px;">decayed for 30, 50 and 60%, respectively. Iron modification of MWCNT in combination with H</span><span style="font-size: 12px;">₂O_2&nbsp;</span><span style="font-size: 12px;">increased the removal rate of selected neonicotinoid for 15&ndash;50%. Presence of intermediates was&nbsp;</span><span style="font-size: 12px;">discovered in systems of dinotefuran with H₂O₂, MWCNT+H</span><span style="font-size: 12px;">₂O₂, e-MWCNT+H₂O_2&nbsp;</span><span style="font-size: 12px;">and of&nbsp;</span><span style="font-size: 12px;">clothianidin in systems with Fe-MWCNT+H₂O_2&nbsp;</span><span style="font-size: 12px;">with m/z of 117,5 and 140,6.&nbsp;</span></p>

Dans un contexte où les inquiétudes environnementales dues à la pollution sont grandissantes à l’échelle globale, la surveillance de la pollution environnementale constitue un enjeu majeur de recherche afin de préserver au mieux un environnement sain et durable. En effet, la surveillance responsable et continue de l’environnement accompagnée par le développement d’alternatives de lutte « verte » contre les nuisibles, pourrait certainement ralentir voir inhiber la propagation de polluants néfastes pour l’ensemble de la biosphère. Dans ce contexte, les objectifs principaux de cette thèse visent d’une part à caractériser la qualité de l’air par une approche basée sur le biomonitoring, et d’autre part à développer un biopesticide d’origine algale permettant la protection des agrumes en post-récolte comme un exemple d’alternative à l’usage des traitements chimiques classiques. Pour répondre au premier objectif, des méthodes d’extraction multi résidus ont dû être développées. Ces méthodes ont été soit spécifiques d’une famille de pesticides tel que les dithiocarbamates, soit plus large et plus générale en considérant de nombreux polluants comme des pesticides, des HAPs et des PCBs. Ces dernières ont été basées soit sur l’ASE-SPE-SPME, soit sur le QuEChERS-SPME, et ont formé le socle des études de biosurveillance environnementale entreprises. Ces études de surveillance ont permis l’évaluation des modifications spatio-temporelles de la qualité de l’air grâce à des espèces naturelles ayant un rôle de capteurs biologique de la pollution environnementale et permettant par la suite l’estimation de la pollution dans des zones bien définies. Pour répondre au second objectif, des extraits aqueux d’algues vertes, Ulva linza et Ulva lactuca, ont été préparés et testés comme antifongiques in vivo et in vitro afin d’étudier leur aptitude à inhiber le développement de Penicillium digitatum sur des agrumes en post récolte. Un potentiel de protection des agrumes en poste-récolte contre ce champignon a été mis en évidence, donnant effectivement l’espoir à la fiabilité de cette approche comme alternative biologique pour le remplacement des pesticides chimiques potentiellement toxiques. / In a context where environmental concerns due to pollution are growing on a global scale, monitoring of environmental pollution is a major research challenge in order to preserve as much as possible a healthy and sustainable environment. Indeed, the responsible and continuous monitoring of the environment escorted by the development of "green" pest control alternatives could certainly decelerate or even inhibit the spread of harmful pollutants into the entire biosphere. In this context, the main objectives of this thesis are intended firstly to characterize air quality by a biomonitoring-based approach and, secondly, to develop a biopesticide of algal origin, that allows the protection of post-harvested citrus fruit, as an alternative to the use of conventional chemical treatments. In order to answer the first objective, multi-residues extraction methods were developed. These methods were either specific to a family of pesticides such as dithiocarbamates or wider and more general regarding numerous pollutants such as pesticides, PAHs and PCBs. The latter were based either on the ASE-SPE-SPME, or on the QuEChERS-SPME, and formed the base of environmental biomonitoring studies undertaken. These monitoring studies allowed the assessment of spatial and temporal changes in air quality through natural species acting as biological sensors of environmental pollution and subsequently allowing the estimation of pollution in well-defined areas. To answer the second objective aqueous extracts of green algae, Ulva linza and Ulva lactuca, were prepared and tested as in vivo and in vitro antifungal agents, in order to study their ability to inhibit the development of Penicillium digitatum on post-harvested citrus fruits. A potential of post-harvested citrus fruits’ protection against this fungus was proved, giving hope to the reliability of this approach as a biological alternative for the replacement of potentially toxic chemical pesticides.

Orientador: Isabel Cristina Sales Fontes Jardim / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-24T08:24:02Z (GMT). No. of bitstreams: 1 Oshita_Daniele_D.pdf: 4645263 bytes, checksum: 6628dba7b8449d1cf1f86afa3dcae9e2 (MD5) Previous issue date: 2013 / Resumo: Este trabalho envolve o desenvolvimento, a otimização e a validação de um método analítico para determinação de multirresíduos de agrotóxicos em amostras de morango, por cromatografia líquida acoplada à espectrometria de massas sequencial (LC-MS/MS). No preparo de amostra utilizou o método QuEChERS (quick, easy, cheap, effective, rugged and safe), que foi testado nas três versões, Original, AOAC Official Method e European Committee for Standardization (CEN) Standard Method EN 15662, além da versão CEN 15662 modificada. Também foram otimizados os solventes de extração, massas do agente secante e, na etapa de clean-up por extração em fase sólida dispersiva (d-SPE), o sorvente comercial PSA (primary secondary amine), alguns preparados no laboratório à base de polímeros de siloxano, como octadecil, octil, amino, fenil, e a mistura PSA e octadecil. As avaliações dos métodos foram baseadas, principalmente, nos valores de recuperação e nos estudos sobre o uso de diferentes sorventes, outros parâmetros que estimam a eficiência do clean-up também foram utilizados, como aspecto físico do extrato final, quantidade de coextratos da matriz, obtida por medidas gravimétricas, e efeito matriz. O método desenvolvido foi validado por meio dos parâmetros analíticos de seletividade, limite de detecção (LOD), limite de quantificação (LOQ), linearidade, exatidão e precisão, conforme o guia Sanco para análises de resíduos de agrotóxicos em alimentos e, posteriormente, amostras comerciais de morango da região de Campinas foram analisadas. O método validado por LC-MS/MS apresentou-se seletivo, preciso, exato e atingiu concentrações abaixo dos respectivos limites máximos de resíduos (LMR) para determinação de agrotóxicos em morango. Este método foi transferido para cromatografia líquida de ultra eficiência (UHPLC), que mostrou redução no tempo de análise, na vazão da fase móvel (FM) e no volume de injeção de amostra e da FM, e similaridade na detectabilidade dos analitos / Abstract: This work involves the development, optimization and validation of an analytical method for multiresidue determination of pesticides in strawberry samples by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Sample preparation used the QuEChERS (quick, easy, cheap, effective, rugged and safe) method, which was tested in three versions, Original, AOAC Official Method and European Committee for Standardization (CEN) Standard Method EN 15662, and also CEN 15662 modified version. The factores optimized were extraction solvents, amount of drying agent and in the clean-up step by dispersive solid phase extraction (d-SPE), the commercial sorbent PSA (primary secondary amine), several prepared in the laboratory based on siloxane polymers, such as octadecyl, octyl, amine, phenyl, and the mixture PSA and octadecyl. The evaluation of the methods was based mainly on the recovery values and for the study of different sorbents, other parameters that estimate the efficiency of the clean-up were also used such as the physical aspect of the final extract, the amount of interference matrix obtained using gravimetric measurements, and the matrix effect. The developed method was validated by the analytical parameters of selectivity, limit of detection (LOD), limit of quantification (LOQ), linearity, accuracy and precision, as described in the Sanco guide for analysis of pesticide residues in foods. After, commercial strawberry samples from the Campinas region were analyzed. The validated method by LC-MS/MS was selective, precise, accurate and reached levels below the respective maximum residue limits (MRLs) for the determination of pesticides in strawberries. This method was transferred to ultra high performance liquid chromatography (UHPLC), which showed a reduction in analysis time, the mobile phase (MP) flow rate and the injection volume of the sample and MP, and similarity in the detectability of the analytes / Doutorado / Quimica Analitica / Doutora em Ciências

The first topic presented in the dissertation thesis is determination of isoprostanes as markers of oxidative stress and other compounds affected by presence of oxidative stress. Isoprostanes iPF2-III, iPF2-VI, iPF2-VI, astaxanthin and polyunsaturated fatty acids (PUFA), especially arachidonic acid (AA) were monitored in Atlantic salmon eggs (Salmo salar). Methods for the determination of these compounds have been developed and optimized using chromatographic separation coupled to conventional or mass spectrometric detection. Freshly laid eggs, eyed embryos and non-viable eggs were used to test a general hypothesis that egg viability can be affected by susceptibility to oxidative stress, either through the specific fatty acid concentration and/or the antioxidant capacity of the eggs. Levels of isoprostanes and arachidonic acid (AA) were significantly higher in non-viable eggs than in control (eyed embryos) as well as relative abundance of PUFA. While no difference of isoprostanes was found between freshly laid and control those from the Atlantic stock except iPF2-VI which was observed under the LOQ in the control. Higher levels of PUFA and AA in comparison with the control were observed in the freshly laid eggs. However, the only statistically significant difference was observed in the amount of astaxanthin. Different levels of PUFA and astaxanthin may be related to their biochemical consumption during the development of eggs. This work evaluated potential effect on the viability of eggs Salmo salar due to the presence of oxidative stress. The monitoring of mycotoxins in food and feed was the subject of the second topic. Mycotoxins are secondary metabolites produced by fungi. They are ubiquitous undesirable natural contaminants that are toxic for humans and animals. Today are known more than 500 mycotoxins. However, only few of them are regulated by the European Union. The European Food Safety Authority (EFSA) was asked by the European Commission to provide a scientific opinion on other mycotoxins for which statutory limits could be developed. In this study is proposed simultaneous screening allowing fast, reliable and sensitive approach, identification and quantification of 17 mycotoxins in food and feed sample. The method includes both mycotoxins regulated by the EU and selected mycotoxins required by the EFSA (aflatoxins, deoxynivalenol, nivalenol, zearalenone, fumonisin, ochratoxin A, T-2 toxin, HT-2 toxin, enniatins and beauvericin). Analytes are isolated by the modified QuEChERS method. For separation and target mycotoxins detection, ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC –MS/MS) was employed. The method also allows determination of ergot alkaloids (ergocornine, ergosine, ergocryptine, ergocristine and their respective epimers). The developed method was used either for monitoring mycotoxins and ergot alkaloids in feed and raw materials and barley and malt prepared from it.

(AJ) Food contact materials pose a risk to human health due to a variety of contaminants which they can release into food. These compounds, migrants, include aromatic hydrocarbons, dialkyl phthalates, bisphenols, printing ink photoinitiators, and perfluoroalkyl compounds. The determination of all these substances can be expensive and time-consuming since universally applicable analytical approaches are not available nowadays. This work attempted to develop methods for the simultaneous determination of migrants from all of the mentioned groups in paper-based food contact materials and fatty food. A total of 68 contaminants were studied in paper products using liquid chromatography and gas chromatography coupled with tandem mass spectrometry detection. All analytes were isolated simultaneously using the modified "QuEChERS" method. This method demonstrated acceptable recovery and repeatability for most analytes in the validation study; LOQs ranged from 1.3 to 220 µg/kg. Analysis of 132 real paper products confirmed the occurrence of almost all studied analytes, which were often present in complex mixtures and at concentrations up to 628 mg/kg. A total of 41 potential contaminants were monitored in fatty foods by liquid chromatography with tandem mass detection. Contamination of the mobile phase by...