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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Avaliação da estabilidade dos compostos bioativos de polpas de frutas nativas submetidas ao processo de irradiação / Evaluation of the stability of bioactive compounds in native fruit pulp exposed to irradiation process

Ana Carolina Leme Castelucci 02 July 2015 (has links)
O Brasil é um dos principais produtores de frutas, porém esta produção está pautada em frutas na maioria das vezes exóticas. Existe uma diversidade de frutas nativas brasileiras ainda desconhecidas e pouco exploradas. Tendo em vista a grande importância da Myrtaceae no que diz respeito à conservação da Mata Atlântica; o potencial econômico e nutricional da produção de polpa de frutas nativas; e considerando que o processamento de alimentos pode exercer efeitos sobre o nível de nutrientes, particularmente no que tange ao teor de compostos bioativos e sua atividade antioxidante, este trabalho teve como objetivo gerar conhecimento sobre a composição e capacidade antioxidante das polpas de frutas, com o intuito de ampliar seu consumo, potencial de comercialização e agregar valor as mesmas, bem como, avaliar o efeito da radiação gama nas propriedades bioativas, durante o período de armazenamento refrigerado das polpas e, por fim, a identificação e quantificação dos compostos fenólicos. As polpas de uvaia (Eugenia pyriformis Camb.), cambuci (Campomanesia phaea), feijoa (Acca sellowiana), grumixama (Eugenia brasiliensis) e cereja do rio grande (Eugenia involucrata), foram divididas em 5 lotes, 4 deles foram submetidos ao tratamento de irradiação (0, 2, 4, e 6 kGy) e 1 lote a pasteurização (85°C/5min.). Os resultados demonstraram que as polpas possuem quantidades expressivas de compostos com atividade antioxidante, sendo que, a polpa de uvaia destacou-se pelos teores de ácido ascórbico, que variaram de 89,99 mg.100 g-1 na pasteurizada a 64,74 mg.100 g-1 a 6 kGy, e pelos carotenoides, que variaram de 24,7 ?g.g-1 no controle a 15,94 ?g.g-1 a 4 kGy. Na feijoa destacam-se os flavonoides no controle, 10,21 mg de ác. gálico.mL-1, nas irradiadas com 2; 4 e 6 kGy, 9,75; 11,58 e 12,79 mg de ác. gálico.mL-1, respectivamente, e na pasteurizada 12,64 mg de ác. gálico.mL-1. As antocianinas foram encontradas em maiores quantidades nas polpas de grumixama (pasteurizadas, 106,01 mg eq. cianidina-3-glicosideo.L-1, irradiadas a 2, 4 e 6 kGy, 52,93; 32,36 e 48,64, respectivamente e no controle 59,75) e cereja do rio grande (pasteurizadas 136,33 mg eq. cianidina-3-glicosideo.L-1, controle 77,11 mg eq. cianidina-3-glicosideo.L-1 e nas irradiadas 74,91; 77,7 e 69,47 mg eq. cianidina-3-glicosideo.L-1, respectivamente a 2, 4 e 6 kGy). Na polpa de cambuci não foram encontrados teores de flavonoides e antocianinas e apresentaram valores relativamente baixos dos outros compostos estudados. O composto fenólico majoritariamente encontrado na polpa de uvaia foi o ácido gálico, na feijoa os ácidos elágico e quínico, no cambuci, o ácido quínico, na grumixama o ácido elágico e a quercetina e na cereja do rio grande o ácido quínico e a rutina. Apesar da radiação gama ser um eficiente método de conservação e poder ser utilizada sem prejuízo dos compostos bioativos, nas condições estudadas, as doses entre 2 e 6 kGy, não foram efetivas para evitar as perdas dos compostos bioativos de interesse, no período de armazenamento, apresentando resultados inferiores em relação à pasteurização quanto às antocianinas, compostos fenólicos totais e a atividade antioxidante, medida por ABTS e DPPH / Brazil is a major producer of exotic native fruits. There is a diversity of native fruits still unknown and slightly researched. Taking into consideration the great importance of Myrtaceae regarding the conservation of the Atlantic Forest; the economic and nutritive potential of the production of native fruit pulp; and considering that the food processing may affect the level of nutrients, particularly with regard to the bioactive compound content and its antioxidant activity, the purpose of this study is to generate knowledge on the composition and the antioxidant capability of Myrtaceae pulps. The study aims at enlarging the consumption of Myrtaceae pulps, their marketing potential and their value-added, as well as at evaluating the effect of gamma radiation on bioactive properties during the cold storage period of pulps, and finally, the identification and quantification of the phenolic compounds. The pulps of uvaia (Eugenia pyriformis Camb.), cambuci (Campomanesia phaea), feijoa (Acca sellowiana), grumixama (Eugenia brasiliensis) and cereja do rio grande (Eugenia involucrata) were divided into 5 batches, 4 of them were exposed to irradiation (0, 2, 4, e 6 kGy) and one batch pasteurization (85°C/5min.) treatments. The results showed that the pulps have an expressive quantity of compounds with antioxidant activity. Uvaia pulp stood out by the ascorbic acid contents, which decreased from 89,99 mg.100 g-1 in pasteurization to 64,74 mg.100 g-1 by 6 kGy, and by the carotenoids, which varied from 24,7 ?g.g-1 in the control sample to 15,94 ?g.g-1 by 4 kGy. Feijoa presented high levels of flavonoids in the control sample, 10,21 mg of gallic acid.mL-1, in irradiation 2; 4 and 6 kGy, 9,75; 11,58 e 12,79 mg of gallic acid.mL-1, respectively, and in pasteurization 12,64 mg of gallic acid.mL-1. The anthocyanins were found in major quantities in the grumixama pulps (in pasteurization, 106,01 mg eq. cianidina-3-glicosideo.L-1, irradiated by 2, 4 e 6 kGy, 52,93; 32,36 e 48,64, respectively and in the control sample 59,75) and cereja do rio grande (in pasteurization 136,33 mg equ. cianidina-3-glicosideo.L-1, in the control sample 77,11 mg equ. cianidina-3-glicosideo.L-1 and irradiated 74,91; 77,7 and 69,47 mg equ. cianidina-3-glicosideo.L-1, respectively by 2, 4 e 6 kGy). Flavoniods and anthocyanins were not found in cambuci pulps. Also, there were low values of the others researched compounds in cambuci pulps. The phenolic compound majorly found in the uvaia pulp was the gallic acid, in the feijoa was the ellagic and quinic acids, in cambuci was the quinic acid, in the grumixama was the ellagic acid and quercetin, and in the cereja do rio grande was the quinic acid and the rutin. Although the gamma radiation revealed to be an efficient conservation method and may be used without prejudice of bioactive compounds, based on the conditions researched, the doses between 2 and 6 kGy were not effective to prevent losses of bioactive compounds of interest in the cold storage period, presenting lower results in relation to the pasteurization treatment as anthocyanins, total of phenolic compounds and the antioxidant activity measured by ABTS and DPPH
12

Recherche de conditions alternatives à l’utilisation de solvants chlorés en Chromatographie Liquide Non-Aqueuse à Polarité Inversée de Phases. Application à l’analyse des lipides présents dans les milieux complexes / Search for alternative conditions for the use of chlorinated solvents in Non-Aqueous Reversed Phases liquid chromatography. Application to the analysis of lipids present in complex media

Hmida, Dorra 22 July 2016 (has links)
Déterminer la composition en triacylglycérols des huiles végétales est un défi important à relever aussi bien en biologie végétale que dans le domaine médical ou celui de l’industrie agro-alimentaire. La chromatographie en phase liquide à polarité inversée de phases en milieu non aqueux (NARP-LC) est la méthode la plus utilisée, avec cependant une utilisation récurrente de solvants chlorés. Le premier objectif de ce travail a été de proposer des conditions analytiques alternatives n’utilisant pas de solvants chlorés. Pour ce faire, nous avons établi le diagramme de force éluante sur phases stationnaires en C18 des phases mobiles binaires constituées d’acétonitrile comme solvant faible et de divers solvants forts (acétone, iso-propanol, acétate d’éthyle, butanol) à quatre températures différentes (25, 43, 63 et 85°C). La comparaison dans des conditions iso-éluantes de l’analyse de 9 huiles de graines contenant une large gamme de TAG nous a permis de montrer que le mélange MeCN/BuOH 74/26 à 25°C est le meilleur choix, en terme de sélectivité pour l’analyse des TAG. Ce qui répond à notre premier objectif. Dans un second temps, nous avons comparé le potentiel séparatif des phases stationnaires de nouvelle génération à petit diamètre de particules, partiellement ou totalement poreuses. L’optimisation des conditions chromatographiques nous a permis de décrire deux systèmes chromatographiques, très performants, en termes d’efficacité et de rapidité. Le premier permet la séparation de TAG contenant des acides gras polyinsaturés isomères de position en C18 : 3 et C18 : 2. L’identification de ces isomères particuliers a été réalisée grâce à la synthèse d’informations complémentaires, obtenues en GC/MS, LC/MS ainsi que l’utilisation de lois de rétention chromatographiques. En outre, ce travail nous a permis de proposer un tableau récapitulatif regroupant un très grand nombre de TAG, qui n’ont jamais été décrits à notre connaissance. Le second permet une analyse rapide de l’huile d’olive, en moins de 5 min, tout en respectant les consignes qualitatives imposées par l’organisme «Conseil Oléique International (COI)». Comparée aux méthodes officielles couramment utilisées, elle mérite d’être proposée comme méthode de référence pour le contrôle de qualité de l’appellation de ces huiles. / The determination of triacylglycerols in vegetable oils is an important challenge in plant biology, in the medical field, and in food industry. Nowadays, non-Aqueous Reversed Phase Liquid Chromatography (NARP-LC) using chlorinated solvents is commonly used for this purpose. The first objective of this work was to develop alternative analytical conditions that can avoid using chlorinated solvents. In a first step, by using C18 stationary phases, we have established the eluotropic solvent strength scale as a function of temperature of several binary mobile phases consisting of acetonitrile as weak solvent and various strong solvents including acetone, isopropanol, ethyl acetate, and butanol. The comparison of the results obtained under iso-eluotropic conditions for nine seed oils containing a wide range of TAG enabled us to show that the MeCN/BuOH (74/26, v/V) mixture operating at 25 °C are the best mobile phase conditions for TAG analysis, in terms of selectivity, thus avoiding the use of chlorinated solvents. In a second step, we compared the separation of TAGs on new generation of fully or partially porous stationary phase particles of small diameter. After optimizing the separating conditions, the obtained data allowed us to propose two highly efficient chromatographic systems. The first system enables the efficient separation of C18:3 and C18:2 positional isomers of C18 polyunsaturated fatty acids containing TAG. For the identification of these TAG isomers, it was necessary to combine the data obtained by GC-MS and LC -MS as well as the data obtained by the application of some chromatographic retention laws. Taken together, these results allowed us to provide a list containing a large number of TAG unknown to date. The second system allows rapid analysis of olive oil in less than 5 min. This system obeying the guidelines of the International Olive Council can be proposed as a candidate reference method for rapid quality control of olive oils.
13

Separation and identification of IgG glycopeptides using Capillary Electrophoresis and Ultra High-Performance Liquid Chromatography-Mass Spectrometry / Separation och identifiering av IgG glykopeptider med kapillärelektrofores och ultra-högupplösande vätskekromatografi- masspektrometri

Lövås, Madeleine January 2022 (has links)
I den här studien har metoder för att separera immunoglobulin (IgG) utvecklats med hjälp av kapillärelektrofores (CE) och Ultra högupplösande vätskekromatografi-Mass spektrometri (UHPLC-MS). Vid analysen av peptider från IgG spjälkat av trypsin (IgG TD) detekterades 26 glykopepeptider med UHPLC-MS genom att använda olika gradienter och mobilfaser. Dessutom analyserades fyra olika koncentrations av IgG TD för att testa detektionsgränsen. Resultatet visade att glykopeptider kunde detekteras i alla fyra koncentrationer men antalet detekterade glykopeptider minskade med minskande koncentration. Den sista delen av UHPLC-MS analysen var en selektivitetsanalys där en blandning av bovint serumalbumin spjälkat av trypsin (BSA TD) och IgG TD analyserades i olika koncentrationer. Selektivitetsanalysen visade att ungefär samma antal IgG glykopeptider detekterades som vid analys av IgG TD. Vid CE-analysen användes tre olika kapillärer, varav två av dem var polyvinylalkohol-coated och olika buffertlösningar (BGE) användes. De slutgiltiga resultaten visade 5 toppar som skulle kunna representera IgG gykopeptider men eftersom ingen MS utfördes kunde inga slutsatser dras. Slutligen, användes Matrix-Assisted Laser desorption/ionisation-time-of-flight (MALDI-TOF) för att analysera proverna innan analys och för att jämföra resultaten med UHPLC-MS. / In this study, methods to separate immunoglobulin G (IgG) glycopeptides were developed using capillary electrophoresis (CE) and ultra-high-performance liquid chromatography-Mass spectrometry (UHPLC-MS). In the UHPLC-MS- analysis, 26 glycopeptides were detected during the analysis of trypsin digested IgG (IgG TD) using different gradients and mobile phases. Moreover, a limit of detection study with four different concentrations (0.01, 0.1, 0.5 and 2mg/mL) was performed. Although the number of detected glycopeptides decreased with decreasing concentration, glycopeptides were detected in the 0.01 mg/mL IgG TD sample. Lastly, a selectivity study was performed, in which two trypsin digested Bovine serum albumin (BSA TD) and IgG TD mixtures with different concentrations were analysed. The results showed that approximately the same number glycopeptides were detected as in the IgG sample suggesting that the BSA sample did not interfere with the detection of glycopeptides. Moreover, the CE-analysis included three different capillaries and several background electrolytes (BGEs). Two of the capillaries were polyvinyl alcohol (PVA) coated. The final electropherogram showed five peaks possibly representing IgG glycopeptides but no MS were performed on the CE part leading to no conclusions for the CE-part. Matrix-Assisted Laser Desorption/Ionisation- time-of flight (MALDI-TOF) was performed throughout the project to control the samples and for comparison to the UHPLC-MS analysis.
14

Caractérisation de métabolites oxygénés dérivés des acides arachidonique et docosahexaénoïque dans le cerveau de rat / Characterization of oxygenated metabolites derived from arachidonic and docosahexaenoic acids in rat brain

Jouvène, Charlotte 15 September 2016 (has links)
Les acides docosahexaénoïque (DHA) et arachidonique (ArA), qui appartiennent respectivement aux familles n-3 et n-6, sont présents en grande quantité dans les tissus cérébraux, en particulier dans les phospholipides membranaires. Ces deux acides gras polyinsaturés (AGPI) jouent des rôles essentiels dans le fonctionnement cérébral, notamment dans le neurodéveloppement et la neuroinflammation. De plus, ces AGPI sont des précurseurs de plusieurs médiateurs lipidiques oxygénés impliqués dans divers processus physiologiques et pathologiques.Dans ce contexte, l'objectif de cette thèse était de caractériser les métabolites oxygénés dérivés du DHA et de l'ArA dans le cerveau, étape cruciale pour une meilleure compréhension de leurs rôles biologiques dans cet organe. Ainsi, une technique d'analyse à haute performance a été utilisée, la chromatographie liquide couplée à de la spectrométrie de masse en tandem (UHPLC-MS/MS), pour identifier les différents métabolites oxygénés dérivés du DHA et de l'ArA présents dans les cerveaux de rats exsanguinés et non exsanguinés, que ce soit en conditions basales ou inflammatoires. Ainsi, plusieurs produits oxygénés dérivés du DHA et de l'ArA ont été identifiés et quantifiés dans les cerveaux exsanguinés et non-exsanguinés, à la fois à l'état libre dans le cerveau mais également estérifiés dans les phospholipides. Les métabolites mono-hydroxylés sont les principaux dérivés oxygénés du DHA et de l'ArA, cependant, des quantités mesurables de produits di-hydroxylés, tels que le 8,15-diHETE et la protectine DX, ont également été détectées. L'exsanguination permet de différencier les métabolites oxygénés du tissu cérébral de ceux présents dans le sang. De plus, le métabolisme oxygéné du DHA et de l'ArA est impacté lors d'une inflammation cérébrale. En effet, dans ces conditions, la synthèse de certains métabolites est augmentée, notamment celle de la protectine D1, molécule connue pour ces fortes propriétés anti-inflammatoires. Ces résultats méritent de plus amples recherches dans des conditions pathophysiologiques, notamment lors de maladies neurodégénératives, afin d'observer leur impact sur le métabolisme oxygéné de ces AGPI / Docosahexaenoic (DHA) and arachidonic (ArA) acids, two PUFA which belong to n-3 and n-6 families respectively, are both present at high amount in brain tissues, and especially in membrane phospholipids. These two polyunsaturated fatty acids (PUFA) play important roles in brain functioning, notably in neurodevelopment and neuroinflammation. Moreover, these PUFA are precursors of various oxygenated lipid mediators involved in diverse physiological and pathological processes. In this context, the aim of this work was to characterize oxygenated metabolites derived from DHA and ArA in brain, crucial step for better understanding their biological roles in this organ. For this purpose, a high performance analytical approach was usd, the liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS), in order to identify the different oxygenated metabolites derived from DHA and ArA in exsanguinated and non-exsanguinated brains, both in basal and inflammatory conditions. Several oxygenated products from DHA and ArA were identified and measured in exsanguinated and non-exsanguinated brain, both in the free form and esterified in phospholipids. Mono-hydroxylated metabolites were the main oxygenated derivatives from DHA and ArA, however, measurable amounts of di-hydroxylated products such as 8,15-diHETE and protectin DX, were also detected. Exsanguination allowed discriminating oxygenated metabolites from brain tissue against those in blood brain. Moreover, DHA and ArA oxygenated metabolism was impacted during brain inflammation. Indeed, in these conditions, the synthesis of some metabolites was increased, including that of protectin D1, molecule known for its strong anti-inflammatory properties. These results deserve further research in pathophysiological conditions, especially in neurodegenerative diseases, in order to observe their impact on the oxygenated metabolism of these PUFA
15

Desenvolvimento de método para a determinação simultânea de resíduos de agrotóxicos e medicamentos veterinários em solo por UHPLC-MS/MS / Development of method for simultaneous determination of pesticide and veterinary drugs residues in soil by UHPLC-MS/MS

Vicari, Michele Camara de 30 August 2013 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Typically, soil is the final destination of pesticides applied in agriculture and of veterinary drugs employed in animal production. The global concern about the possible consequences of the increased use of these compounds is reflected in increasingly stringent regulations on the levels of residues in agricultural products, animal products and in the environment. This results in intensifying the demand for environmental certification, reduction of Maximum Residue Levels in food and the introduction of procedures for traceability in production processes. In this study, we compared different extraction methods: mechanical agitation, ultrasound and QuEChERS for the determination of 76 pesticides and 9 veterinary drugs in soil using Ultra High Performance Liquid Chromatography coupled to tandem Mass Spectrometry (UHPLC-MS/MS). The extraction method that showed the best results consisted of weighing 10 g of soil followed by the addition of 10 mL of water and kept at rest for 10 min. Then added 10 mL of acetonitrile containing 1% (v/v) acetic acid and proceeded with mechanical shaking for 15 min. Then, it was added 4 g of anhydrous magnesium sulfate and 1.7 g of anhydrous sodium acetate and shaked manually and vigorously for 1 min. Subsequently, the tube was centrifuged for 8 min (3400 rpm) and the extract was filtered and diluted (1:4, v/v) in water before analysis by UHPLC-MS/MS. The method was validated by evaluating several parameters, such as linearity of analytical curves, limits of detection and quantification (LOD and LOQ), matrix effect, as well as accuracy an precision in terms of percentage of recovery and RSD. The analytical curves prepared in solvent and in the blank matrix extract showed linearity for most compounds, with coefficients of determination greater than 0.99, and the standard curves prepared in "blank" matrix extract were used to evaluate the matrix effect. To verify the accuracy and precision of the method, fortification in four concentration levels (10, 25, 50 and 100 μg kg-1) we performed, and extracted in replicate (n = 6), resulting in recovery values between 70 to 120%, with RSD lower than 20% for most of the compounds. Values of method LOQ and LOD were from 3.0 to 7.5 μg kg-1 and from 10 to 25 μg kg-1, respectively. After validation, the method was applied to the determination of pesticides and veterinary drugs in real samples, it showed to be very efficient to be applied in routine analysis. / Normalmente, o solo é o destino final dos agrotóxicos utilizados na agricultura e dos medicamentos veterinários utilizados na criação de animais. A preocupação mundial com as possíveis consequências do aumento do uso destes compostos se reflete em regulamentações cada vez mais exigentes sobre os níveis de resíduos nos produtos agrícolas, produtos de origem animal e no ambiente. Isso resulta na intensificação da demanda por certificação ambiental, redução dos limites máximos de resíduos em alimentos e a introdução de procedimentos que permitam a rastreabilidade nos processos produtivos. Neste estudo, comparou-se diferentes métodos de extração, sendo eles, agitação mecânica, ultrassom e QuEChERS para a determinação de 76 agrotóxicos e 9 medicamentos veterinários em solo utilizando Cromatografia Líquida de Ultra Eficiência acoplada à Espectrometria de Massas em Série (UHPLC-MS/MS). O método de extração que apresentou os melhores resultados consistiu na pesagem de 10 g de solo, seguido da adição de 10 mL de água e mantido em repouso por 10 min. Em seguida adicionou-se 10 mL de acetonitrila contendo 1% (v/v) de ácido acético e procedeu-se a agitação mecânica por 15 min. Logo após, acrescentou-se 4 g de sulfato de magnésio anidro e 1,7 g de acetato de sódio anidro e agitou-se manual e vigorosamente por 1 min. Posteriormente, o tubo foi centrifugado por 8 min (3400 rpm) e o extrato foi filtrado e diluído (1:4, v/v) em água antes da análise por UHPLC-MS/MS. O método foi validado avaliando-se vários parâmetros, como linearidade das curvas analíticas, limites de detecção e quantificação (LOD e LOQ), efeito matriz, assim como exatidão e precisão, em termos de percentual de recuperação e RSD. As curvas analíticas preparadas no solvente e no extrato branco da matriz apresentaram linearidade adequada para a maioria dos compostos, com valores de coeficiente de determinação maiores que 0,99, sendo que as curvas analíticas preparadas no extrato branco da matriz foram utilizadas para compensar o efeito matriz. Para verificar a exatidão e precisão do método, efetuou-se a fortificação em quatro níveis de concentração (10, 25, 50 e 100 μg kg-1), e extração em replicata (n = 6), obtendo-se valores de recuperação entre 70 e 120%, com RSD menores que 20% para a grande maioria dos compostos. Os valores de LOD e LOQ do método variaram entre 3,0 e 7,5 μg kg-1 e 10 e 25 μg kg-1, respectivamente. Após a validação, o método foi aplicado para a determinação de agrotóxicos e medicamentos veterinários em amostras reais, mostrando-se bastante eficiente para ser aplicado em análises de rotina.
16

Determinação multirresíduo de agrotóxicos em bebidas à base de soja empregando método QuEChERS e UHPLC-MS/MS / Multiresidue determination of pesticides in soy-based beverages using a QuEChERS method and UHPLC-MS/MS

May, Marília Melina 26 February 2016 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Soy beverages are aqueous extracts of soybeans which are a source of high quality protein and no contains cholesterol or lactose, can be considered functional foods. These beverages have a large acceptance among consumers and due to they are extracted from the grain, the beneficial components are preserved, but may also contain residues of pesticides used to control pest infestation during the growing of the grains. This study aimed to develop and validate a multiresidue method based on QuEChERS extraction for the simultaneous determination of 41 pesticides in soy-based beverages using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). In the sample preparation step, it was used 10 mL of sample and 10 mL of acetonitrile and addition of salts. The clean-up procedure was optimized by experimental design, evaluating different quantities of the sorbents primary secondary amine (PSA) and octadecylsilane (C18).The clean-up step was performed with magnesium sulfate anhydrous and C18. To assess the accuracy of the method, blank samples were spiked at 10, 25 and 50 μg L-1 with n = 6. To evaluate the matrix effect, inclinations of curves in acetonitrile and blank extract of the matrix were compared. The results of the validation are satisfactory, since the method presented optimized recoveries between 70 and 112% with RSD less than 19%. Curves were prepared in the matrix extract, due to some compounds presented pronounced matrix effect. The curves showed r² ≥ 0,99 for all compounds in the range between the respective limit of quantification and 50 μg L-1. The method proved to be suitable for the determination of the compounds and may be used for routine analysis. / Bebidas à base de soja são extratos aquosos do grão de soja, que representam uma fonte de proteínas de alta qualidade e não contém colesterol ou lactose, podendo ser consideradas alimentos funcionais. Essas bebidas têm grande aceitabilidade entre consumidores e por serem extraídas do grão, os componentes benéficos são preservados, mas também podem conter resíduos de agrotóxicos empregados para controlar a infestação de pragas durante o cultivo dos grãos. O presente trabalho teve por objetivo desenvolver e validar um método multirresíduo baseado na extração por QuEChERS para a determinação simultânea de 41 agrotóxicos em bebidas à base de soja por meio de cromatografia líquida de ultra alta eficiência acoplada à espectrometria de massas em série (UHPLC-MS/MS). Na etapa de preparo de amostra, utilizou-se 10 mL de amostra e 10 mL de acetonitrila e adição de sais. O procedimento de limpeza dos extratos foi otimizado a partir de planejamento experimental, avaliando diferentes quantidades dos sorventes amina primária secundária (PSA) e octadecilsilano (C18). A etapa de limpeza dos extratos foi realizada com sulfato de magnésio anidro e C18. Para avaliar a exatidão do método, amostras branco foram fortificadas nos níveis de 10, 25 e 50 μg L-1, com n = 6. Para avaliação do efeito matriz foram comparadas as inclinações de curvas em acetonitrila e no extrato branco da matriz. Os resultados da validação foram satisfatórios, já que o método otimizado apresentou recuperações entre 70 e 112%, com RSD menor que 19%. As curvas foram preparadas no extrato da matriz, devido a alguns compostos apresentarem efeito matriz acentuado. Foi obtido r² ≥ 0,99 para todos os compostos, na faixa entre os respectivos limites de quantificação e 50 μg L-1. O método provou ser adequado para a determinação dos compostos e pode ser utilizado para análises de rotina.
17

Determinação de contaminantes emergentes em água utilizando microextração adsortiva em barra (BAμE) e UHPLC-MS/MS / Determination of emerging contaminants in water using bar adsorptive microextraction (BAμE) AND UHPLC-MS/MS

Souza, Maiara Priscilla de 25 August 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The emerging pollutants are substances that enter continuously in the environment and are being more recognize due to the advancement of instrumental and sample preparation techniques. These contaminants include several chemical classes, such as pharmaceuticals, hormones, personal care products, flame retardants and others. Water is one of the most susceptible matrix since the sewage discharge is one of the main routes of environmental pollution. Bar adsorptive microextration (BAμE) has shown great analytical capacity for the analysis of organic compounds in residual level and has become a well-established analytical tool in sample preparation. In this work, a simple and low cost method was validated for the analysis of 13 emerging contaminants in water using BAμE with polymeric sorbent followed by ultra high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS). The preparation, stability tests and development of BAμE devices are also discussed. Eleven different coating phases were evaluated. In order to select the best combination of experimental conditions for extraction and back extraction, central composite design (CCD) with four variables was applied. Validation results were satisfactory, since the method presented recoveries between 74% and 118% with relative standard deviations (RSD) < 19%. The analytical performance presented detection and quantification limits of 0.012 to 0.6 and 0.04 to 2 μg L-1, respectively. The proposed method combines a simple and effective sample preparation for the determination of emerging contaminants in water using a microextraction technique (BAμE) followed by UHPLC-MS/MS analysis. The method applicability was evaluated using real samples of surface, drinking and tap water and 6 positive samples were found indicating the presence of bisphenol A (0.08-0.665 μg L-1) and paracetamol (0.104-4.2 μg L-1). / Os contaminantes emergentes são substâncias que entram continuamente no meio ambiente e que estão sendo reconhecidas com maior profundidade devido ao avanço de técnicas instrumentais e de preparo de amostra. Estes compostos englobam diversas classes químicas, como por exemplo, fármacos, hormônios, produtos de higiene e cuidado pessoal, retardantes de chama, dentre outros. Uma das matrizes mais suscetíveis à contaminação é a água tendo em vista que a descarga de esgoto é uma das principais vias de poluição ambiental. A microextração adsortiva em barra (BAμE) tem demonstrado grande capacidade analítica para a análise de compostos orgânicos em nível residual e vem se tornando uma ferramenta analítica bem estabelecida no âmbito de preparo de amostras. Neste estudo foi desenvolvido e validado um método simples e de baixo custo para a determinação de 13 contaminantes emergentes em água utilizando BAμE e empregando sorvente polimérico com posterior análise por cromatografia liquida de ultra eficiência acoplada à espectrometria de massas em série (UHPLC-MS/MS). O preparo das barras bem como os testes de estabilidade foram avaliados. Onze sorventes foram testados para revestir os dispositivos. A fim de avaliar a melhor combinação de parâmetros para a extração e dessorção dos analitos, utilizou-se um planejamento do composto central (CCD) com 4 variáveis. Os resultados da validação foram satisfatórios uma vez que as recuperações obtidas ficaram entre 74% e 118% com desvio padrão relativo RSD < 19%. Os limites de detecção e quantificação foram de 0,012 a 0,6 e 0,04 a 2,0 μg L-1, respectivamente. O método proposto combina uma etapa de preparo de amostra simples e eficaz para a determinação de contaminantes emergentes em água. A aplicabilidade do método foi avaliada utilizando amostras reais de água de superfície, de torneira e mineral e destas, 6 amostras apresentaram bisfenol A (0,08-0,665 μg L-1) e paracetamol (0,104-4,2 μg L-1).
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Recherche et validation de biomarqueurs lipidiques du globule rouge par chromatographie en phase liquide couplée à la spectrométrie de masse. Application au diagnostic et au suivi thérapeutique de la maladie de Gaucher / Research and validation of red blood cell lipid biomarkers based on liquid chromatography-tandem mass spectrometry. Application to the diagnosis and monitoring of Gaucher disease

Chipeaux, Caroline 18 December 2019 (has links)
Chez l’homme, les erreurs innées du métabolisme des lipides sont dues à des déficits enzymatiques, entraînant une accumulation intracellulaire de substrats lipidiques. Il en résulte un large éventail de symptômes tels que des atteintes viscérales, osseuses et dans certains cas neurologiques. En outre, de nombreux patients atteints de ce type de maladie présentent des anomalies hématologiques et vasculaires attribuées à des anomalies rhéologiques du globule rouge (GR). Ces observations ont conduit à l’hypothèse de l’existence d’un lien entre les propriétés anormales du GR et sa composition lipidique. Or actuellement, le profil lipidique du GR normal reste méconnu. Cependant, le diagnostic précoce de ces troubles est d’une importance capitale pour la prise en charge des patients, notamment dans les cas où un traitement correctif est disponible. La maladie de Gaucher (MG) de type 1, qui est une maladie lysosomale caractérisée par un déficit en β-glucocérébrosidase et pour laquelle un traitement enzymatique substitutif (ERT) est proposé, en est le meilleur exemple. D’où l’intérêt de disposer d’un outil simple et rapide de diagnostic de ce type de maladie.Dans le cas de la MG, le diagnostic repose encore sur la mise en évidence, laborieuse, du déficit enzymatique. Néanmoins, des travaux récents suggèrent que les anomalies rhéologiques du GR pourraient être dues à l’accumulation de quatre sphingolipides, le glucosylcéramide, la glucosylsphingosine, la sphingosine et la sphingosine-1-phosphate, qui seraient de bons candidats biomarqueurs. Or, les méthodes actuelles de dosage de ces sphingolipides nécessitent au moins deux étapes chromatographiques, avec pour chacune une étape longue et fastidieuse de préparation de l’échantillon, ce qui ne facilite guère une approche lipidomique de ce sujet. En outre, seul le glucosylcéramide a été dosé dans le GR tandis que les trois autres sphingolipides n’ont été dosés que dans le plasma. Ces candidats biomarqueurs restent donc à valider.Dans cette thèse, nous avons développé et validé une méthode simple et rapide, par UHPLC-MS/MS, de dosage simultané des 4 sphingolipides impliqués dans la MG. L’application de cette méthode à des GR provenant de patients atteints de la MG, en collaboration avec l’Institut National de Transfusion Sanguine et la société Shire, nous a permis de : 1- valider un biomarqueur parmi les quatre proposés et de montrer que les trois autres n’étaient pas suffisamment spécifiques ; 2- vérifier l’efficacité du traitement ERT actuellement proposé et 3- confirmer l’hypothèse de départ reliant les anomalies rhéologiques du GR à sa composition lipidique.De même, une étude systématique des conditions opératoires nous a permis de généraliser la méthode proposée à l’identification et au dosage de l’ensemble des sphingolipides présents dans un GR ainsi que des phospholipides, constituants majoritaires de sa membrane. Appliquée à la quantification simultanée d’une trentaine de sphingolipides et de phospholipides dans le GR normal et celui de la MG, cette méthode nous a permis de mettre en évidence l’implication d’autres lipides polaires dans la maladie de Gaucher, outre les 4 sphingolipides jusqu’alors proposés. De même, il est prévu de l’adapter à moyen terme pour le profilage total, par classe, de tous les lipides présents dans le GR.Enfin, nous avons évalué d’autres techniques de SM telles que la haute résolution et la mobilité ionique (TWIMS et DIMS) dans le but d’affiner la recherche de nouveaux biomarqueurs, notamment par l’identification des lipides isomères non discriminables par les techniques de MS conventionnelles. Grâce à une collaboration avec le Laboratoire de Chimie Physique (LCP, CNRS UMR 8000) nous avons montré la faisabilité de cette approche en séparant en DIMS deux isomères : la galactosylsphingosine 18:1 et la glucosylsphingosine 18:1 et nous poursuivons actuellement cette étude pour séparer d’autres couples d’isomères. / In humans, hereditary disorders of lipid metabolism are due to enzyme deficiencies, resulting in intracellular accumulation of lipid substrates. This results in a wide range of symptoms such as visceral, bone and in some cases neurological disorders. Furthermore, many patients suffering such diseases have hematologic and vascular symptoms attributed to red blood cell (RBC) rheological abnormalities. These observations led to a hypothesis linking RBC abnormal properties to its lipid composition. However, the lipid profile of normal RBC remains unknown to date. Early diagnosis of these conditions is of importance notably when a therapy is available. This is the case for Gaucher disease (GD) type 1, a lysosomal disorder characterized by β-glucocerebrosidase deficiency, where an enzyme replacement therapy (ERT) is proposed. Hence, the availability of a simple and rapid tool of diagnosis of such a disorder is of great importance, notably for a better patient care and monitoring.To the best of our knowledge, standard diagnosis procedures and monitoring of GD patients are still based on the tedious evaluation of enzyme deficiency. Nevertheless, recent works suggest that these rheological disorders may be due to the accumulation of four sphingolipids, glucosylceramide, glucosylsphingosine, sphingosine and sphingosine-1-phosphate, which could be considered as relevant biomarkers. However, most of current determination methods of these sphingolipids require at least two liquid chromatographic runs, each with a time-consuming sample preparation step that does not facilitate a lipidomic approach. In addition, only glucosylceramide was quantified in RBC while the other three sphingolipids were quantified only in plasma. Thus, these biomarker candidates remain to be validated.In this PhD, we describe a simple and rapid UHPLC-MS/MS method of simultaneous determination of the 4 sphingolipids involved in GD in both plasma and RBC. The application of this method to RBC from GD patients, in collaboration with the Institut National de Transfusion Sanguine and Shire (USA), allowed us: 1- to validate one biomarker among the four proposed candidates and to show that the other three candidates are not specific; 2- to check the efficiency of the proposed ERT and 3- to confirm the initial hypothesis linking the RBC rheological abnormalities to its lipid composition.Also, a systematic study of the operating conditions allowed us to generalize the proposed method to the determination of not only all the sphingolipids present in RBC but also all phospholipids, which are the major constituents of its membrane. The application of the later method to the simultaneous quantification of thirty sphingolipids and phospholipids in normal and GD RBCs, allowed us to validate it and to unravel the involvement of other candidate biomarkers of GD, different from the 4 previous sphingolipids. Providing appropriate modifications, this method is intended to be used for the profiling of all lipid classes in plasma and RBC. This is our main objective in the medium-term.Finally, we evaluated other modern MS techniques such as high resolution (HRMS) and ion mobility (TWIMS and DIMS) in order to refine the investigation of new biomarker candidates, including the separation of lipid isomers that cannot be discriminated by conventional MS techniques. Indeed, in collaboration with the Laboratoire de Chimie Physique (LCP, CNRS UMR 8000), we here show the feasibility of this approach by achieving the separation of two isomers, by the DIMS technique: galactosylsphingosine 18:1 and glucosylsphingosine 18:1, which cannot be separated by conventional methods. We are currently pursuing these investigations in order to separate other isomers.
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Agrotóxicos em vinho: avaliação do método QuEChERS e da microextração líquido-líquido dispersiva na determinação multirresíduo por UHPLC-MS/MS / Pesticides in wine: evaluation of QuEChERS method and dispersive liquid-liquid microextraction for the multiresidue determination by UHPLC-MS/MS

Bernardi, Gabrieli 10 March 2017 (has links)
The widespread use of pesticides in agriculture has brought many benefits such as, increasing quantity and quality of crops grown. However, there is a concern regarding to the presence of pesticide residues in the consumed manufactured food products. Due to this, it is necessary to monitor pesticides in these products in order to verify compliance with maximum residue limits. Wine is a beverage obtained from grape must, but the grapes grown for this purpose are susceptible to pest attack and the occurrence of fungal diseases. Since the wine quality is related to the grapes quality, its production is dependent on the use of pesticides. Currently, the most useful way to determine the pesticides residues in food is the application of multiresidue methods that allow the determination of several compounds from different classes in a single analytical process. Based on that, the aim of this work was to evaluate two multiresidue methods for the extraction of pesticides in wine, one of them being based on the QuEChERS method and the dispersive liquid-liquid microextraction with the use of demulsifying solvent (SD-DLLME). Parameters that affect the extraction efficiency of both methods were studied and after established the best extraction conditions the methods were validated. The use of ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) allowed to perform the determination with high selectivity and sensitivity. For the QuEChERS method, 97 compounds were validated and the limit of quantification of the method (LOQ) ranged from 10 to 20 μg L-1. For SD-DLLME, 74 compounds were validated and LOQ were between 0.1 and 0.2 μg L-1. Among the compounds not validated by SD-DLLME are compounds with polar characteristics, not suitable for this technique. Pesticides residues of different classes were found in the samples the concentrations of 0.8 to 55.3 μg L-1. In view of the results obtained, the use of SD-DLLME proved to be a viable alternative to the QuEChERS method for the multiresidue determination of pesticides in wine. / O uso generalizado de agrotóxicos na agricultura trouxe muitos benefícios em relação ao aumento da quantidade e qualidade das culturas produzidas. Entretanto, existe uma preocupação com relação à presença de resíduos de agrotóxicos nos alimentos e produtos comerciais consumidos. Devido a isso, torna-se necessário o monitoramento de agrotóxicos nesses produtos a fim de verificar a observância dos limites máximos de resíduos. O vinho é uma bebida obtida a partir do mosto da uva, porém as uvas cultivadas para esse fim são suscetíveis ao ataque de pragas e a ocorrência de doenças fúngicas. Uma vez que a qualidade do vinho depende fortemente da qualidade das uvas, a sua produção é dependente do uso de agrotóxicos. Atualmente, a maneira mais útil para determinação de resíduos de agrotóxicos em alimentos é a aplicação de métodos multirresíduo que permitam a determinação de inúmeros compostos, de diversas classes, em um único processo analítico. Pensando nisso, esse trabalho teve como objetivo a avalição de dois métodos de extração multirresíduo de agrotóxicos em vinho, sendo um deles baseado no método QuEChERS e outro na técnica de extração denominada microextração líquido-líquido dispersiva com uso de solvente demulsificante (SD-DLLME). Os parâmetros que afetam a eficiência de extração foram estudados para ambos e depois de encontradas as melhores condições de extração os mesmos foram validados. A determinação por cromatografia líquida de ultra-alta eficiência acoplada à espectrometria de massas em série (UHPLC-MS/MS) permitiu a realização das análises com alta seletividade e sensibilidade. Para o método QuEChERS foram validados 97 compostos sendo que o limite de quantificação do método (LOQm) variou de 10 a 20 μg L-1. Para a SD-DLLME, 74 compostos foram validados e o LOQm entre 0,1 e 0,2 μg L-1. Dentre os compostos que não foram validados pela SD-DLLME estão compostos com características polares, não adequados para essa técnica. Os métodos validados foram utilizados para a determinação de agrotóxicos em amostras de vinho. Foram encontrados resíduos de agrotóxicos de diferentes classes nas concentrações de 0,8 a 55,3 μg L-1. Tendo em vista os resultados obtidos, a utilização da SD-DLLME demonstrou ser uma alternativa viável ao método QuEChERS para determinação multirresíduo de agrotóxicos em vinho.
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Beneficiamento primário de Passiflora Incarnata L., para obtenção de vitexina por cromatografia líquida de ultra eficiência em Botucatu (SP) / Primary processing of Passiflora Incarnata L., to obtain vitexin by ultra-high performance liquid chromatography in Botucatu (SP)

Gonçalves, Maiara Cristina [UNESP] 31 August 2017 (has links)
Submitted by Maiara Cristina Gonçalves null (maiara.sp@hotmail.com) on 2017-10-31T22:26:38Z No. of bitstreams: 1 Maiara_C_Gonçalves_Dissertaçãof.pdf: 10457679 bytes, checksum: a5a48ce58f99b4fe8a29392db8f2e4f5 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-11-13T13:01:38Z (GMT) No. of bitstreams: 1 goncalves_mc_me_bot.pdf: 10457679 bytes, checksum: a5a48ce58f99b4fe8a29392db8f2e4f5 (MD5) / Made available in DSpace on 2017-11-13T13:01:38Z (GMT). No. of bitstreams: 1 goncalves_mc_me_bot.pdf: 10457679 bytes, checksum: a5a48ce58f99b4fe8a29392db8f2e4f5 (MD5) Previous issue date: 2017-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Objetivo da pesquisa foi avaliar o processo de beneficiamento primário de Passiflora incarnata realizado no município de Botucatu com a inclusão de um sistema de monitoramento da temperatura e umidade de baixo custo, por meio de um software open-source em um secador artesanal á lenha e a avaliação do processamento póscolheita da biomassa de P. incarnata, quantificando teor de vitexina por CLUE-EM. O trabalho foi desenvolvido no sítio Dois Irmãos, entre as coordenadas geográficas, latitude 22º56’49,27” Sul e longitude 48º34’42,80” Oeste, aos 765 m de altitude no distrito de Rubião Júnior, bairro rural Chaparral. Acompanhou-se a colheita e o beneficiamento de P. incarnata durante dois anos (2015 e 2016). A metodologia utilizada foi a de observação direta. A estrutura do secador confeccionado pelo produtor familiar de alvenaria (barro-cimento), reutilizando uma construção que já existia na área. Para a avaliação do teor de vitexina foram escolhidos e marcados seis indivíduos de P. incarnata e coletados durante as três épocas de colheita de 2016 (abril, setembro e novembro) e três tratamentos prévios à secagem de fragmentação: parte aérea não fragmentada (NF); fragmentada média, de 1 cm a 5 cm (FM), e fragmentada pequena, abaixo de 0,5 cm (FP). As análises de CLUE-EM foram realizadas em espectrômetro de massas Accela (Thermo Scientific® ) modelo LCQ Fleet com Ion Trap 3D via análise de injeção de fluxo (FIA) e ionização por eletronebulização com separações cromatográficas realizadas em coluna de fase reversa (C18) e a fase móvel composta de uma mistura de MeOH:H2O. A desidratação da parte aérea do P. incarnata ocorre, em média, durante cerca de 22 horas e meia, parando no período noturno por (11 horas) atingindo umidade relativa máxima de 73,8 % e mínima de 9,6 % e temperaturas máxima e mínima, respectivamente, de 53,5 e 20,9° C. Durante todo processo de desidratação o secador manteve a temperatura interna acima da temperatura do ambiente e a umidade relativa do ar abaixo da umidade do ambiente cumprindo sua função mesmo nos momentos que não foi alimentado por lenha. Apesar da grande variação nos teores de vitexina do tratamento não fragmentado e da segunda época de colheita e a média dos tratamentos não apresentaram diferenças significativas entre os tipos de fragmentação pré-secagem e teores de vitexina, sendo a fragmentação recomendada para facilitar o processo de secagem da espécie. / The objective of this research was to evaluate the process of primary processing of Passiflora incarnata in a low cost temperature and humidity monitoring system, which was carried out in Botucatu by means of an open-source software in a wood-fired drier and the evaluation of the post-harvest processing of the P. incarnata biomass by the vitexin content by UHPLC-MS with a data metabolic approach.The work was developed in Dois Irmãos, between the geographical coordinates, latitude 22º56'49.27 "South and longitude 48º34'42.80" West, at 765m altitude in the district of Rubião Júnior, rural district Chaparral. The experiment was conducted with different seasons of harvest and beneficiation of P. incarnata during two years (2015 and 2016).The methodology used was direct observation and photographic record. The structure of the dryer made by the producer was masonry (clay-cement), reused a construction that already existed in the area. Six individuals of P. incarnata were used to evaluate the vitexin content during the three harvest seasons in 2016 (april, september and november) and three treatments prior to fragmentation drying: nonfragmented aerial part (NF); Fragmented medium from 1 cm to 5 cm (FM) and small fragmented, below 0.5 cm (FS). The UHPLC-MS analysis was performed on an Accela mass spectrometer (Thermo Scientific ®) LCQ Fleet model with Ion Trap 3D via flow injection analysis (FIA) and electrospray ionization with reverse phase (C18) column chromatographic separations and the mobile phase composed of a mixture of MeOH:H2O. The dehydration of the shoot of the wild passion fruit occurred for twenty two and a half hours, the relative humidity reached at 73.8% (maximum) and 9.6% (minimum), the temperature kept between 53.5 and 20.9° C. With the dehydration process the internal temperature of dryer kept above of ambient temperature , whiule the air relative humidity stayed below of the ambient humidity, which guaranteed its function even without fueled by firewood accidentally.

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