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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.
31

Contribuições para o desenvolvimento de método por GCxGC para a análise de nitro-HPAs em material particulado no ar / Contributions to the GCxGC method development for the analysis of nitro-PAHs in airborne particulate material

Silvana Odete Pisani 20 May 2013 (has links)
Os hidrocarbonetos policíclicos aromáticos nitrados (nitro-HPAs) são potencialmente genotóxicos, por isso existe um grande interesse na determinação analítica desses compostos no material particulado no ar. Os nitro-PAHs são emitidos diretamente para a atmosfera pela combustão incompleta ou podem ser formados in situ a partir dos HPAs precursores. Neste trabalho, são apresentados os resultados obtidos no desenvolvimento de um método de análise de nitro-HPAs (1-nitronaftaleno, 2-nitronaftaleno, 1-nitropireno, 2-nitropireno, 2-nitrofluoranteno, 3-nitrofluoranteno, 1,3-dinitropireno, 1,6- dinitropireno, 2-nitrofluoreno, 6-nitrocriseno, 7-nitrobenzo(a)antraceno, 9- nitroantraceno e 9-nitrofenantreno) por GCxGC. A separação destes compostos por GCxGC pode simplificar a etapa de pré-tratamento do extrato orgânico oriundo do material particulado no ar. A GCxGC promove a separação em duas colunas com mecanismos de separação diferentes, conectadas em série, o que resulta em uma capacidade de separação maior. O sistema GCxGC empregado neste trabalho possui um injetor com programação de temperatura (PTV), um modulador criogênico de dois jatos de CO2 líquido (Dual Jet) e um detector por ionização em chama (FID). A separação foi feita empregando a fase estacionária apolar 5% fenil polisilfenilene siloxano na primeira coluna (30 m / 0,25 mm / 0,25 µm) e a semipolar 14% cianopropilfenil polisiloxano na segunda coluna (1 m / 0,10 mm / 0,10 µm). Diferentes condições cromatográficas foram testadas, como: programação de temperatura no PTV, de 40-90ºC até 350ºC, com taxa de aquecimento de 2,2 e 14,5ºC/s; programação de temperatura no forno, de 40-90ºC até 300ºC, com taxa de aquecimento de 2, 2,5 e 3ºC/min; períodos de modulação de 3, 4 e 5s. O volume injetado foi 2µL, no modo splitless; a vazão do gás de arraste (He) foi constante e igual a 1 mL/min e o detector FID foi operado em 120 Hz. As larguras de pico medidas em 10% da altura variaram de 167 a 350ms para 1- nitronaftaleno e 6-nitrocriseno, respectivamente, e a capacidade de pico para o conjunto de colunas de separação usado foi estimada em cerca de 9800. Parâmetros de validação, tais como os limites de detecção (200 a 500 ng/mL) e de quantificação (650 a 1600 ng/mL) para alguns nitro-HPAs foram determinados. Para a quantificação, foram testados os métodos por padronização interna e externa, sendo que, através dos resultados deste trabalho, pode-se mostrar que a determinação de nitro-HPAs por GCxGC com o modulador empregado é possível se for feita através do método de padronização interna. O sistema GCxGC empregado causou dificuldades operacionais, principalmente na conexão das colunas e na modulação. Perdas de massa de analito foram detectadas nas análises por GCxGC, muito provavelmente causadas por uma conexão parcial das colunas. Isso poderia ser evitado se a conexão fosse feita pela fusão das colunas a um conector de vidro adequado a essa finalidade. Picos modulados divididos foram observados com frequência, o que comprometeu a precisão e exatidão dos resultados. A divisão dos picos ocorreu de modo aleatório dificultando a identificação da causa mais provável para a sua ocorrência. Cromatogramas GCxGC de extratos orgânicos não fracionados de particulados no ar, oriundos de queima direta de palha de cana-de-açúcar, de região afetada pela queima de cana-de-açúcar e de área urbana da cidade de São Paulo, mostraram a potencialidade do método / Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are potentially genotoxic, so there is a great interest in the analytical determination of these compounds in airborne particulate matter. The nitro-PAHs are emitted directly into the atmosphere by incomplete combustion or may be formed in situ from PAHs. In this work, results obtained from the development of an analytical method for nitro-PAHs by GCxGC are presented. The nitro-PAHs studied were: 1- nitronaphthalene, 2-nitronaphthalene, 1-nitropyrene, 2-nitropyrene, 2- nitrofluoranthene, 3-nitrofluoranthene, 1,3-dinitropyrene, 1,6-dinitropyrene, 2- nitrofluorene, 6-nitrochrysene, 7-nitrobenzo(a)anthracene, 9-nitroanthracene and 9- nitrophenanthrene. The separation of these compounds by GCxGC should simplify the pretreatment step of the airborne particulate organic extract. In GCxGC two capillary columns of different mechanisms of separation are coupled by an interface called modulator, which increase significantly the chromatographic resolution. The GCxGC system used in this work is equipped with a PTV injector, a dual-stage double jets CO2 cryogenic modulator and a flame ionization detector (FID). The separation was carried out using a nonpolar stationary phase 5% methyl phenyl polysiloxane in the first column (30 m / 0.25 mm / 0.25 µm) and a semipolar 14% cyanopropyl phenyl dimethyl polysiloxane in the second column. Different chromatographic conditions were tested: the PTV was programmed from 40-90ºC to 350ºC at 2.2 and 14.5ºC/s; the oven was programmed from 40-90ºC to 350ºC at 2.0, 2.5 and 3.0ºC/min; the modulation periods tested were 3, 4 and 5s. The injected volume was 2µL in splitless mode, the carrier gas (He) flow rate of 1 mL/min was constant and the FID detector was operated at 120 Hz. Validation parameters, such as the limit of detection (200 - 500 ng/mL) and quantitation (650 - 1600 ng/mL) were determined. For quantification, the internal and external standardization methods were tested, and through the results of this study, it can be shown that the determination of nitro-PAHs by GCxGC with the modulator used is possible if made by internal standardization method. The GCxGC system presented operational difficulties, particularly in the column connection and in the modulation zone. A partial connection of the columns resulted in mass loss of the analytes. The connection of the columns could be more effective if it was made by fusing the columns to a glass connector suitable for this purpose. Divided modulated peaks were frequently observed, which compromised the precision and accuracy of the results. The division of the peaks occurred randomly hindering the identification of the most likely cause for its occurrence. GCxGC chromatograms corresponding to unfractionated organic extracts of airborne particulate material from the sugarcane straw burning, from an area impacted by sugar cane burning emissions and from an urban area of São Paulo City showed the capability of the method.
32

Contribuições para o desenvolvimento de método por GCxGC para a análise de nitro-HPAs em material particulado no ar / Contributions to the GCxGC method development for the analysis of nitro-PAHs in airborne particulate material

Pisani, Silvana Odete 20 May 2013 (has links)
Os hidrocarbonetos policíclicos aromáticos nitrados (nitro-HPAs) são potencialmente genotóxicos, por isso existe um grande interesse na determinação analítica desses compostos no material particulado no ar. Os nitro-PAHs são emitidos diretamente para a atmosfera pela combustão incompleta ou podem ser formados in situ a partir dos HPAs precursores. Neste trabalho, são apresentados os resultados obtidos no desenvolvimento de um método de análise de nitro-HPAs (1-nitronaftaleno, 2-nitronaftaleno, 1-nitropireno, 2-nitropireno, 2-nitrofluoranteno, 3-nitrofluoranteno, 1,3-dinitropireno, 1,6- dinitropireno, 2-nitrofluoreno, 6-nitrocriseno, 7-nitrobenzo(a)antraceno, 9- nitroantraceno e 9-nitrofenantreno) por GCxGC. A separação destes compostos por GCxGC pode simplificar a etapa de pré-tratamento do extrato orgânico oriundo do material particulado no ar. A GCxGC promove a separação em duas colunas com mecanismos de separação diferentes, conectadas em série, o que resulta em uma capacidade de separação maior. O sistema GCxGC empregado neste trabalho possui um injetor com programação de temperatura (PTV), um modulador criogênico de dois jatos de CO2 líquido (Dual Jet) e um detector por ionização em chama (FID). A separação foi feita empregando a fase estacionária apolar 5% fenil polisilfenilene siloxano na primeira coluna (30 m / 0,25 mm / 0,25 µm) e a semipolar 14% cianopropilfenil polisiloxano na segunda coluna (1 m / 0,10 mm / 0,10 µm). Diferentes condições cromatográficas foram testadas, como: programação de temperatura no PTV, de 40-90ºC até 350ºC, com taxa de aquecimento de 2,2 e 14,5ºC/s; programação de temperatura no forno, de 40-90ºC até 300ºC, com taxa de aquecimento de 2, 2,5 e 3ºC/min; períodos de modulação de 3, 4 e 5s. O volume injetado foi 2µL, no modo splitless; a vazão do gás de arraste (He) foi constante e igual a 1 mL/min e o detector FID foi operado em 120 Hz. As larguras de pico medidas em 10% da altura variaram de 167 a 350ms para 1- nitronaftaleno e 6-nitrocriseno, respectivamente, e a capacidade de pico para o conjunto de colunas de separação usado foi estimada em cerca de 9800. Parâmetros de validação, tais como os limites de detecção (200 a 500 ng/mL) e de quantificação (650 a 1600 ng/mL) para alguns nitro-HPAs foram determinados. Para a quantificação, foram testados os métodos por padronização interna e externa, sendo que, através dos resultados deste trabalho, pode-se mostrar que a determinação de nitro-HPAs por GCxGC com o modulador empregado é possível se for feita através do método de padronização interna. O sistema GCxGC empregado causou dificuldades operacionais, principalmente na conexão das colunas e na modulação. Perdas de massa de analito foram detectadas nas análises por GCxGC, muito provavelmente causadas por uma conexão parcial das colunas. Isso poderia ser evitado se a conexão fosse feita pela fusão das colunas a um conector de vidro adequado a essa finalidade. Picos modulados divididos foram observados com frequência, o que comprometeu a precisão e exatidão dos resultados. A divisão dos picos ocorreu de modo aleatório dificultando a identificação da causa mais provável para a sua ocorrência. Cromatogramas GCxGC de extratos orgânicos não fracionados de particulados no ar, oriundos de queima direta de palha de cana-de-açúcar, de região afetada pela queima de cana-de-açúcar e de área urbana da cidade de São Paulo, mostraram a potencialidade do método / Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are potentially genotoxic, so there is a great interest in the analytical determination of these compounds in airborne particulate matter. The nitro-PAHs are emitted directly into the atmosphere by incomplete combustion or may be formed in situ from PAHs. In this work, results obtained from the development of an analytical method for nitro-PAHs by GCxGC are presented. The nitro-PAHs studied were: 1- nitronaphthalene, 2-nitronaphthalene, 1-nitropyrene, 2-nitropyrene, 2- nitrofluoranthene, 3-nitrofluoranthene, 1,3-dinitropyrene, 1,6-dinitropyrene, 2- nitrofluorene, 6-nitrochrysene, 7-nitrobenzo(a)anthracene, 9-nitroanthracene and 9- nitrophenanthrene. The separation of these compounds by GCxGC should simplify the pretreatment step of the airborne particulate organic extract. In GCxGC two capillary columns of different mechanisms of separation are coupled by an interface called modulator, which increase significantly the chromatographic resolution. The GCxGC system used in this work is equipped with a PTV injector, a dual-stage double jets CO2 cryogenic modulator and a flame ionization detector (FID). The separation was carried out using a nonpolar stationary phase 5% methyl phenyl polysiloxane in the first column (30 m / 0.25 mm / 0.25 µm) and a semipolar 14% cyanopropyl phenyl dimethyl polysiloxane in the second column. Different chromatographic conditions were tested: the PTV was programmed from 40-90ºC to 350ºC at 2.2 and 14.5ºC/s; the oven was programmed from 40-90ºC to 350ºC at 2.0, 2.5 and 3.0ºC/min; the modulation periods tested were 3, 4 and 5s. The injected volume was 2µL in splitless mode, the carrier gas (He) flow rate of 1 mL/min was constant and the FID detector was operated at 120 Hz. Validation parameters, such as the limit of detection (200 - 500 ng/mL) and quantitation (650 - 1600 ng/mL) were determined. For quantification, the internal and external standardization methods were tested, and through the results of this study, it can be shown that the determination of nitro-PAHs by GCxGC with the modulator used is possible if made by internal standardization method. The GCxGC system presented operational difficulties, particularly in the column connection and in the modulation zone. A partial connection of the columns resulted in mass loss of the analytes. The connection of the columns could be more effective if it was made by fusing the columns to a glass connector suitable for this purpose. Divided modulated peaks were frequently observed, which compromised the precision and accuracy of the results. The division of the peaks occurred randomly hindering the identification of the most likely cause for its occurrence. GCxGC chromatograms corresponding to unfractionated organic extracts of airborne particulate material from the sugarcane straw burning, from an area impacted by sugar cane burning emissions and from an urban area of São Paulo City showed the capability of the method.
33

Comprehensive two-dimensional gas chromatography (GCxGC ) for drug analysis

Song, Shin Miin, shinmiin@singnet.com.sg January 2006 (has links)
Separation technologies have occupied a central role in the current practices of analytical methods used for drug analysis today. As the emphasis in contemporary drug analysis shifts towards ultra-trace concentrations, the contribution from unwanted matrix interferences takes on greater significance. In order to single out a trace substance with confidence from a rapidly expanding list of drug compounds (and their metabolites) in real complex specimens, analytical technologies must evolve to keep up with such trends. Today, the task of unambiguous identification in forensic toxicology still relies heavily upon chromatographic methods based on mass spectrometric detection, in particular GC-MS in electron ionisation (EI) mode. Although the combined informing power of (EI) GC-MS has served faithfully in a myriad of drug application studies to date, we may ask if (EI) GC-MS will remain competitive in meeting the impending needs of ultra-trace drug analysis in the fut ure? To what extent of reliability can sample clean-up strategies be used in ultra-trace analysis without risking the loss of important analytes of interest? The increasing use of tandem mass spectrometry with one-dimensional (1D) chromatographic techniques (e.g. GC-MS/MS) at its simplest, considers that single-column chromatographic analysis with mass spectrometry alone is not sufficient in providing unambiguous confirmation of the identity of any given peak, particularly when there are peak-overlap. Where the mass spectra of the individual overlapping peaks are highly similar, confounding interpretation of their identities may arise. By introducing an additional resolution element in the chromatographic domain of a 1D chromatographic system, the informing power of the analytical system can also be effectively raised by the boost in resolving power from two chromatographic elements. Thus this thesis sets out to address the analytical challenges of modern drug analysis through the application of high resolut ion comprehensive two-dimensional gas chromatography (GC„eGC) to a series of representative drug studies of relevance to forensic sciences.
34

Desenvolvimento de métodos cromatográficos hifenados (in-tube SPME/LC-FLD e GCxGC/qMS) para análises de fármacos e agrotóxicos em amostras complexas / Development of hyphenated chromatographic methods (in-tube SPME/LC-FLD and GCxGC/MS) for analysis of drugs and pesticides in complex samples.

Bruno José Gonçalves da Silva 25 July 2011 (has links)
As determinações, em níveis de traços, de fármacos em fluidos biológicos e de multirresíduos (contaminantes) em amostras alimentícias são de extrema importância, pois geram valiosos dados para fins, respectivamente, de monitorização terapêutica (individualização do regime de dosagem) e controle de qualidade (segurança alimentar). A demanda por métodos analíticos de alta resolução e com baixos limites de quantificação, para análises de amostras complexas, tem impulsionado a química analítica para o desenvolvimento de soluções inovadoras, destacando-se aquelas voltadas ao desenvolvimento ou avaliação de novos sistemas analíticos. Neste contexto, na primeira etapa desta tese, o sistema automatizado de microextração em fase sólida no capilar de polipirrol (in-tube PPY SPME) acoplado à cromatografia líquida com detecção fluorimétrica foi desenvolvido (lab-made) para a determinação enantiosseletiva de fluoxetina e de seu metabólito norfluoxetina em amostras de plasma, para fins de monitorização terapêutica. Na segunda etapa, o método cromatografia gasosa bidimensional abrangente acoplada à espectrometria de massas com analisador quadrupolo (GC x GC / qMS) foi padronizado e validado para análise de multirresíduos de agrotóxicos em tomates frescos, para fins de controle de qualidade. Dentre os resultados obtidos podemos destacar: na primeira etapa o ganho de seletividade da fase extratora de polipirrol, em sistema miniaturizado e automatizado de preparo de amostra, hifenado à separação cromatográfica (LC) com detecção fluorimétrica; e na segunda etapa, o incremento da resolução cromatográfica e detectabilidade do sistema de cromatografia gasosa bidimensional com detecção espectrométrica com analisador quadrupolo. As análises de amostras de plasma de pacientes em terapia com fluoxetina e de amostras de tomates comerciais comprovaram a aplicabilidade dos métodos propostos, padronizados e validados, em níveis de concentrações que incluem o intervalo terapêutico preconizado para a fluoxetina em plasma e os limites máximos de resíduos de agrotóxicos estabelecidos para a cultura de tomate. / Determination of trace levels of drugs in biological fluids and multiresidue (contaminants) in food samples is extremely important because this generates valuable data for therapeutic drug monitoring (individualization of dosage regimen) and quality control (food safety), respectively. Because of the demand for analytical methods with high resolution and low limits of quantification for analysis of complex samples, analytical chemistry has stimulated the development of innovative approaches, especially those aimed at developing or evaluating new analytical systems. In this context, in the first stage of this thesis the automated solid-phase microextraction capillary polypyrrole (in-tube \"PPY SPME) coupled to liquid chromatography with fluorimetric detection was developed (lab-made) for enantioselective determination of fluoxetine and its metabolite norfluoxetine in plasma samples for therapeutic drug monitoring. In the second stage of this work, the GC x GC / qMS method was developed for multiresidues analysis of pesticides in fresh tomatoes for the purpose of quality control. In the first stage of the research the gain in terms of the selectivity of the polypyrrole extraction phase in hyphenated and automated system for sample preparation and chromatographic separation (LC) with fluorimetric detection is worthy of note. As for the second step, the highlight is the improvement in chromatographic resolution as well as in the detectability system of the system consisting of two-dimensional gas chromatography and spectrometric detection with quadrupole analyzer. Analyses of plasma samples from patients undergoing therapy with fluoxetine and of samples of commercially available tomatoes proved the applicability of the proposed methods, which were optimized and validated at concentrations levels that include the therapeutic range for the analyzed drugs in plasma and the maximum residue limits of pesticides for growing tomatoes.
35

Analyse et valorisation des matières premières à odeur boisée : ciblage des composés odorants / Analysis and valuation of raw materials with woody smell : targeting odorous compounds

Tissandié, Loïc 20 December 2018 (has links)
Ce mémoire de doctorat rassemble les travaux réalisés dans le cadre d’une étude analytique approfondie et systématique des substances à odeur boisée. Ces substances définissent une famille d’ingrédients unanimement appréciés pour leurs notes puissantes et recherchés par les parfumeurs pour composer les accords parmi les plus emblématiques de la profession. Les matières premières inscrites au programme de cette étude sont les essences de Gaïac, d’Araucaria, de Patchouli, de Cyprès Jaune d’Alaska, de Vétiver et d’Agarwood, ainsi que certains de leurs produits dérivés. La plupart de ces matières premières sont couramment utilisées par l’industrie du parfum. Leur spécificité provient de leur composition chimique très largement dominée par les dérivés sesquiterpéniques, conférant ainsi à ces extraits une complexité moléculaire indéniable. Les principaux objectifs de cette thèse de doctorat ont consisté à améliorer la connaissance de ces matières premières en termes de composition chimique, à déterminer autant que possible les composés odorants contribuant à leur odeur, et enfin d’explorer d’éventuelles voies de valorisation pour ces mêmes ingrédients à l’échelle industrielle.La méthodologie analytique développée tout au long de l’étude a nécessité l’utilisation combinée d’un large éventail de techniques chromatographiques, spectrométriques et spectroscopiques pour parvenir à caractériser ces matières premières au plus près et à réaliser l’isolement de leurs constituants inconnus. Ainsi, ces travaux s’articulent autour de quatre outils centraux : la chromatographie gazeuse bidimensionnelle intégrale couplée à la spectrométrie de masse (GC × GC–MS), la chromatographie gazeuse couplée à l’olfactométrie (GC–O), la chromatographie gazeuse semi-préparative (GC prép.) et la résonance magnétique nucléaire (RMN). Près de 190 composés ont été isolés et caractérisés dont 107 sont décrits pour la première fois comme constituants d’extraits naturels. / This Ph.D. dissertation sums up the work carried out as part of a thorough and systematic analytical study of woody-scented substances. These substances define a family of ingredients unanimously appreciated for their powerful notes, and sought by perfumers to compose some of the most emblematic accords in perfumery. The raw materials included in the frame of this study are the oils of Guaiac, Araucaria, Patchouli, Alaska Yellow Cypress, Vetiver, and Agarwood, as well as some of their by-products. Most of these raw materials are ingredients commonly used by the perfume industry. Their chemical specificity comes from their composition largely dominated by sesquiterpene derivatives, giving these extracts an undeniable molecular complexity. The main objectives of this Ph.D. thesis were to improve the knowledge of these raw materials in terms of chemical composition, to determine as much as possible the odorous compounds contributing to their odor, and finally to explore possible ways of valorization for these products on an industrial scale.The analytical methodology developed throughout this study required the combined use of a wide range of chromatographic, spectrometric, and spectroscopic techniques in order to characterize these raw materials as precisely as possible and achieve the isolation of their unknown constituents. Thus, our work revolved around four central tools: comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC-MS), gas chromatography-olfactometry (GC–O), preparative capillary-gas chromatography (pc-GC) and nuclear magnetic resonance (NMR). Almost 190 compounds have been isolated and characterized, 107 of which are described for the first time as constituents of natural extracts.
36

Bisfenol A ve vodním ekosystému / Bisphenol A in water ecosystem

Nohelová, Gabriela January 2014 (has links)
This diploma thesis deals with Bisphenol A, especially with its impact on the aquatic ecosystem. Information about its properties, production and current use are summarized here. Its harmful impact on the environment, especially on the aquatic ecosystem and the human body is characterized. Also the methods of its degradation within the aquatic environment have been described. A summary of the options of a determination of Bisphenol A in water samples is incorporated and the method of gas chromatography with mass spectrometry (GC/TOF MS) and comprehensive two-dimensional gas chromatography with mass spectrometry (GCxGC/TOF-MS) is compared in the experimental part. Analytical determination precedes the isolation of the analyte from the water samples by solid phase extraction (SPE) using SupelcleanTM ENVITM - 18 and derivatization using the silylation reagent, N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). The result of this work is the analysis of a series of real samples from wastewater treatment plants Brno Modřice and Luhačovice by a two-dimensional gas chromatography with mass spectrometry (GCxGC/TOF-MS).
37

Analýza sexuálního feromonu ovocných mušek rodu Ceratitis fasciventris, Ceratitis anonae a Ceratitis rosa / Analýza sexuálního feromonu ovocných mušek rodu Ceratitis fasciventris, Ceratitis anonae a Ceratitis rosa

Faťarová, Mária January 2013 (has links)
Ceratitis fasciventris, Ceratitis anonae and Ceratitis rosa are polyphagous agricultural pests originating from African continent. Their behaviour is heavily altered by pheromones. Insect chemical communication channels are species-specific, represents taxonomic and reproduction barriers. Taxonomy of this group (so-called Ceratitis FAR complex) is unclear. Therefore new chemical approaches along with genetic tests for identification of entities within the cryptic species FAR complex are being developed. To study multi-component mixtures of male volatiles originating from the three mentioned fruit fly species, comprehensive two-dimensional gas chromatography with time- of-flight mass spectrometer (GC×GC-TOFMS) was used. A number of compounds were identified, out of which 23 were found to be distributed and shared among the studied species, 11 out of these were present in all three species. Analyses of male pheromone volatiles, using gas chromatography combined with electroantennographic detector (GC-EAD) revealed 4 common compounds with antennal activity shared among three studied species: methyl (E)-hex-3-enoate, 6-methylhept-5-en-2- one, linalool, and methyl (2E,6E)-farnesoate. The species-specific EAD active compounds in C. fasciventris were esters of isomers of hexenoic acid, whereas isomers of...
38

Analýza těkavých látek lidského tělesného pachu pomocí komprehenzivní dvoudimenzionální plynové chromatografie / Analysis of a human body odour using comprehensive two-dimensional gas chromatography

Bušovská, Radka January 2021 (has links)
Body odour perception plays an important role in human mate choice, especially in women. It was previously proposed that women select partners whose body odour resembles that of woman's fathers. Yet, this phenomenon has only been confirmed using ethological studies based on subjective perception of body odour similarities. Therefore, the aim of my diploma thesis was to test this hypothesis instrumentally using comprehensive GC×GC-TOFMS and subsequent multidimensional analyses of body odour chemical profiles of male partners and fathers of adult women. Body odour sampling from left and right axilla of fathers and partners of 41 women (altogether 164 samples) was performed using cotton swabs, which were then frozen and extracted into hexane. Typical human volatile substances, such as hydrocarbons, carboxylic acids, esters, alcohols, aldehydes, ketones, sterols and terpenes were detected in all examined samples. Using a newly available "tile-based" chromatographic alignment algorithm, we obtained a set of 341 compounds systematically occurring in male axillary odour. The principal component analysis was used to calculate Euclidean distances for all pairs of the studied male subjects. These estimates of "chemical distances" revealed to be significantly smaller for father-partner pairs of individual...
39

Analýza složení samčího sexuálního feromonu různých populací tropické ovocné mušky Ceratitis capitata (Diptera, Tephritidae) / Analysis of male sex pheromone of different population of tropic fruit fly Ceratitis capitata (Diptera, Tephritidae)

Ježková, Zuzana January 2012 (has links)
The Ceratitis capitata is a very important agricultural pest, whose reproduction behaviour is controled by chemical signals. Males initiate mating by creating leks, where they release sexual pheromones to attract females. The main goal of this diploma thesis was to determine the influence of host plants on the composition of male sex-pheromones C. capitata and to compare emanations of wild males with those originating from laboratory population. We studied the chemical composition of volatiles, released by calling males C. capitata from laboratory and two wild populations, using two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC-TOFMS), gas chromatography with electroantennographic and flame ionization detection (GC-EAD-FID). All data were statistically analyzed by multivariate data analyses. Significant differences were observed in the quantitative and qualitative composition of the chemical emanations among males from the three populations. The GC-EAD-FID analyses revealed fourteen antenally active compounds with a possible behavioral function. Isomenthone, geraniol, bornyl acetate, geranyl acetone and ethyl octanoate were newly identified antenally active compounds of C. capitata male sex pheromone. Statistical analyses indicated that males and females of...
40

Využití plynové chromatografie s hmotnostně spektrometrickou detekcí pro posouzení kontaminace odpadních a povrchových vod rezidui léčiv / Application of Gas Chromatography with Mass Spectrometric Detection for the Assessment of Drug-residue Contamination of Wastewaters and Surface Waters

Lacina, Petr January 2012 (has links)
This work is based on the current issue of increasing concentrations of pharmaceutical residues in various components of the environment. These new environmental contaminants continuously enter the environment. The most affected environmental component is the aquatic environment. This study is focused on the development and optimization of reliable analytical method, which can determine selected drugs in the aquatic environment (waste waters and surface waters) qualitatively and quantitatively. The target compounds were selected mainly from the group of non-steroidal anti-inflammatory drugs (NSAID): salicylic acid, acetylsalicylic acid, clofibric acid, ibuprofen, acetaminophen, caffeine, naproxen, mefenamic acid, ketoprofen and diclofenac. NSAIDs are one of the most used drugs in Czech Republic. For the final analysis of this study was used the comprehensive two-dimensional gas chromatography with mass spectrometric detection Time-of-Flight (GCxGC-TOF MS). It is a very sensitive and reliable analytical method for trace and ultra-trace analysis. Simultaneously, solid phase extraction (SPE) and derivatization are optimized in this work. Optimized analytical method including SPE, derivatization with MSTFA (N-methyl-N-(trimethylsilyl) trifluoroacetamide) and final analysis by GCxGC-TOF MS were applied successfully for the analysis of real samples. Samples of waste water were collected from the waste water treatment plant in Brno – Modřice and samples of surface water were collected from two river streams Svratka and Svitava in Moravian region. The range of concentrations of selected drug residues varied from one to tens of g/L in wastewater and from tens to hundreds of ng/L in surface waters. The degree of wastewater and surface waters contamination by drug residues is assessed in conclusions of the work. Simultaneously, spontaneous degradation of selected drugs in water and removal efficiency of the wastewater treatment plant is assessed in conclusions of the work. The developed method is usable for monitoring and environmental analysis of water ecosystems. It is usable not only for selected drugs, but even for other organic compounds with similar properties.

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