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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.
1

Odour Communication in Pieris Butterflies

Andersson, Johan January 2004 (has links)
<p>QCR 20161026</p>
2

Site Assessment and Remediation Feasibility Study of a Petroleum Hydrocarbons Contaminated Site

Wu, Long-chem 07 September 2004 (has links)
This study presents detailed procedures for site assessment, remedial system design, and optimization of the remedial action operation (RAO) for the petroleum-hydrocarbons contaminated sites. In this work, a petroleum-hydrocarbons contaminated site located in southern Taiwan was selected. Contaminants of concerns (CoCs) from leaking underground storage tanks (USTs) and associated piping included mono-aromatics (e.g., benzene, toluene, ethyl-benzene, xylenes), naphthalene, and aliphatic hydrocarbons. The direct push (DP) technology was adopted for soil gas and soil samples collection. CoCs in the affected subsurface soils and the aquifers were determined by solid-phase micro-extraction/gas chromatography/mass spectrometry and several other analytic instruments. Site investigation via various tests was conducted to evaluate the geology, hydrogeology, bioactivity and free product availability. Based on results of specific site characterization, successful hydraulic containment and substantial recovery of observed free-phase petroleum product were achieved. During the process of field-scale remediation, a test cell which was equipped with a subset of monitoring points and numerous different function active wells (injection well, extraction well, monitoring well, soil gas monitoring probe, reference well and recovery well) was used for remedial system evaluation. A treatment train consisting of the source control treatment and in situ groundwater treatment technology was employed in this study. The former included a vertical containment barrier (i.e., slurry wall) and three pumping wells, whereas the latter included some passive remedial activities. Approximately 87% to 95% decline of the CoCs concentration was observed in those monitor wells after 135 days of operation. Results show that the spilled light non-aqueous phase liquids (LNAPLs) could be efficiently contained and removed using the treatment train system. The treatment train application could be successfully used to reduce the concentrations of CoCs in groundwater to satisfactory levels. Benzene was found to be the only compound in groundwater violating the groundwater pollution control standard. The risk assessment process including hazard identification and exposure assessment was conducted to assess the risk impact of benzene on the human health. Using the methodology approved by ASTM and American Petroleum Institute (API), the baseline carcinogenic risk (9.0E-07) and risk-based groundwater screening level for benzene (0.660 mg/L) were determined. The BIOPLUME III model was also applied to simulate the transport and fate of benzene in site groundwater. Results from this study indicate that site assessment coupled with the treatment train could be used to reduce the concentrations of CoCs in groundwater and soil to satisfactory levels efficiently and effectively.
3

Odour Communication in Pieris Butterflies

Andersson, Johan January 2004 (has links)
No description available.
4

Tipificação de meis brasileiros por micro-extração em fase solida combinada com cromatografia gasosa (SPME-CG) / Characterization of Brazilian honeys by solid phase microextraction gas chomatography (SPME-CG)

Silva, Ana Claudia Lemes da 18 December 2006 (has links)
Orientador: Fabio Augusto / Tese (doitorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-11T06:52:57Z (GMT). No. of bitstreams: 1 Silva_AnaClaudiaLemesda.pdf: 2973527 bytes, checksum: 8d640c252ae8364f2e60128332ab484c (MD5) Previous issue date: 2006 / Resumo: O mel é uma das misturas mais complexas de carboidratos produzida pela natureza. É um alimento energético muito importante pelas suas propriedades nutritivas, pelo seu aroma e sabor que dependem fortemente das plantas, flores e condições climáticas presentes na região geográfica onde está localizada a colméia. Não existem metodologias que possibilitem identificação não subjetiva, rápida e confiável da origem floral do mel. O objetivo deste trabalho foi desenvolver uma metodologia que permitisse a identificação da origem floral de méis brasileiros a partir da caracterização química de sua fração de voláteis utilizando micro-extração em fase sólida através do headspace e cromatografia gasosa (HS-SPME-CG). Para o desenvolvimento da metodologia, foram avaliadas 90 amostras de méis brasileiros de vinte origens florais diferentes e variadas procedências geográficas. Onze destas amostras eram unitárias e permitiram apenas um estudo exploratório. Cada tipo de mel apresentou um perfil cromatográfico diferente. Foram identificados potenciais marcadores para os méis de eucalipto (Eucalyptus sp), laranja (Citrus sp), assa-peixe (Vernonia polianthes), cambará (Lantana montevidensis), morrão de candeia (Croton sp) e marmeleiro (Cydonia vulgaris). Os resultados obtidos mostraram que SPME-CG é útil na tipificação de méis e pode eventualmente ser utilizada na sua certificação / Abstract: Honey is one of the most complex mixtures of carbohydrates produced by Nature. It is a very important energetic food for its nutritional properties and for its aroma and flavor that depend strongly on the fauna, flowers and on the climatic conditions in the geographic region where the beehive is located. There are no objective, fast and reliable methodologies for the identification of the floral source of honeys. The objective of this work was to develop a methodology to allow identification of the floral source of Brazilian honeys through characterization of its volatile fraction using headspace solid phase microextraction and gas chromatography (HS-SPME-GC). To develop the methodology, 90 samples of Brazilian honeys of twenty different botanical sources and several geographic locations were employed. Eleven honey types had just one sample, allowing only exploratory studies. Different chromatographic profiles were obtained for honeys from different floral sources. Potential chemical markers were identified for the honeys of eucaliptus (Eucalyptus sp), orange (Citrus sp), assa-peixe (Vernonia polianthes), lantana (Lantana montevidensis), morrão of candeia (Croton sp) and quince (Cydonia vulgaris). The results obtained showed that SPME-GC is useful to identify the floral origin of honey and may eventually be used for its certification / Tese (doitorado) - Universidad / Quimica Analitica / Doutor em Ciências
5

Estudo de aromas de algumas espécies frutíferas Amazônicas pela técnica de HS-SMPE-GC-MS

Ribeiro, Aline Larissa Campos Fernandes 30 April 2015 (has links)
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-05-23T19:48:50Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Aline L. C. F. Ribeiro.pdf: 906747 bytes, checksum: c41283b56c0e807e3ab0268c6781aed2 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-05-23T19:49:08Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Aline L. C. F. Ribeiro.pdf: 906747 bytes, checksum: c41283b56c0e807e3ab0268c6781aed2 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-05-23T19:49:25Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Aline L. C. F. Ribeiro.pdf: 906747 bytes, checksum: c41283b56c0e807e3ab0268c6781aed2 (MD5) / Made available in DSpace on 2017-05-23T19:49:25Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Aline L. C. F. Ribeiro.pdf: 906747 bytes, checksum: c41283b56c0e807e3ab0268c6781aed2 (MD5) Previous issue date: 2015-04-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The need to identify the volatile composition of food is growing every year, mainly driven by the industry. The volatile compounds present in food is very important because they are responsible for their characteristic aroma, which in turn contributes to the taste and consequently to the attraction for the food. The attractive taste of tropical fruits is increasing the consumption of these fruits worldwide, and hence the aroma and flavor of these fruits are getting attention of the industry. Considering this growing interest and the fact that the aroma of most amazonian fruits have not yet been studied, the aim of this study was the characterization of the aroma of three Amazon edible fruits consumed in Manaus region: banana pacovan (Musa paradisiaca L), cajarana (Spondias dulcis Park) and cubiu (Solanum sessiliflorum Dunal). The volatile compounds were extracted by Headspace Solid Phase Microextraction technique and the components were separated and identified by high resolution gas chromatography coupled to mass spectrometry. Two types of commercial SPME fibers were used, CAR-PDMS and PDMS, to compare their efficiency. The extraction capability for each fiber has varied, PDMS fiber was able to extract more components for banana and cubiu, whereas CAR-PDMS for cajarana. Alcohols, aldehydes and esthers were identified in all three fruits, and esthers were more present in cubiu. Terpenes were identified solely in cajarana and carboxylic acids were present only in banana pacova aroma. / A necessidade do conhecimento da composição dos voláteis em alimentos vem crescendo a cada ano, principalmente impulsionada pela indústria. As substâncias voláteis presentes em um alimento são importantes, pois são elas que conferem o seu aroma característico, que por sua vez contribui para o sabor e consequentemente pela atração pelo alimento. O sabor atrativo das frutas tropicais está estimulando o consumo destas frutas em todo o mundo e, devido a isso, o aroma e sabor destes frutos vêm chamando a atenção das indústrias, demonstrando o interesse na caracterização de cada uma delas. Tendo em vista esse grande interesse e o fato do aroma da maioria dos frutos exóticos amazônicos não terem sido estudados ainda, este trabalho teve como objetivo a caracterização do aroma de três frutos comestíveis adquiridos na região de Manaus: banana pacovan (Musa paradisiaca L), cajarana (Spondias dulcis Park) e cubiu (Solanum sessiliflorum Dunal). Os componentes voláteis foram extraídos utilizando a técnica de microextração em fase sólida por “headspace” e a identificação foi realizada através de análises por cromatografia gasosa de alta resolução acoplada com espectrometria de massas. Para a extração dos voláteis, dois tipos de recobrimento de fibra foram utilizados, CAR-PDMS e PDMS, que são normalmente utilizadas nas análises de voláteis. Os resultados obtidos para análise dos aromas de todos os frutos estudados mostraram que a quantidade de substâncias extraídas variou entre as fibras. Os resultados para a banana e para o cubiu apresentaram maior quantidade de componentes extraídos com a fibra PDMS, enquanto para a cajarana foi obtido com a fibra CAR-PDMS. Nos três frutos foram identificadas substâncias voláteis pertencentes à classe de álcoois, aldeídos e ésteres, que foi a principal classe encontrada em todas as análises, principalmente no cubiu. Terpenos foram identificados apenas no aroma da cajarana e ácidos carboxílicos apenas no aroma da banana pacovan.
6

Identification of the Active Odors From Illicit Substances for the Development of Optimal Canine Training Aids

Huertas-Rivera, Adhly M 04 November 2016 (has links)
The exploitation of illicit substances, such as drugs and explosives, is on the rise. Special attention must therefore be considered to reduce the transportation and storage of these illicit substances by improving the capability of detection, even when hidden from view. Although analytical methods of detection for both drugs and explosives have improved over time, biological detectors, such as canines, are still commonly used. In comparison to humans, these canines have a larger number of olfactory receptors and a greater olfactory epithelium surface area, providing them with a more enhanced olfaction than that of humans. The premise for the detection of illicit drugs and explosives is based on the premise that these substances though hidden, will emit volatile organic compounds (VOCs). These VOCs are not often the parent drug or explosive, they are essentially a chemical associated with the source and provide a reliable indication of the illicit substance. Previous successful research has been conducted on the identification of the active odors present in the headspace of cocaine, methamphetamine, and MDMA but instead for marijuana and heroin there have been minimum success. Thus, in the present research a method using headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) was optimized to identify the VOCs makeup of heroin and marijuana to further identify the active odor compound(s) responsible for the alert response of biological detectors (canines). A mixture of acetic acid and acetylsalicylic acid was identified as target odor mimic for heroin by certified detector canines, while a mixture of limonene and caryophyllene was recognized as odor mimic for marijuana by conducting ORTs. The training aids developed successfully mimic the scent of the actual illicit substance and can be used to improve the capabilities of both drug and explosive detection canines. Additionally, as growing threat of improvised explosives has created a worldwide concern and emphasized the requirement of a greater spectra of canine training aids that covers the complete range of explosives available, a new approach for the creation of training aids for IEDs have been evaluated. The use of a dynamic collection system have proved to be an option to develop fast and reliable canine training aids for IEDs.
7

ELECTROCHEMICALLY-AIDED CONTROL OF SOLID PHASE MICRO-EXTRACTION (EASPME) USING CONDUCTING POLYMER COATED FIBER

CEYLAN, OZCAN January 2003 (has links)
No description available.
8

Desenvolvimentos metodologicos em microextração em fase solida acoplada a cromatografias gasosa e liquida / Methodological developments for solid-phase microextraction coupled to gas and liquid chomatography

Sartoratto, Adilson 12 July 2006 (has links)
Orientador: Fabio Augusto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-08T00:55:46Z (GMT). No. of bitstreams: 1 Sartoratto_Adilson_D.pdf: 1221656 bytes, checksum: f0ebb01e44d95590f9bbda739169bb32 (MD5) Previous issue date: 2006 / Resumo: O trabalho que teve como objetivo desenvolver metodologias em Microextração em Fase Sólida para utilização em cromatografia líquida e gasosa será apresentado em dois capítulos: no primeiro capítulo a análise de pesticidas organofosforados (OPP) em amostras aquosas e infusão de plantas foi realizada por cromatografia líquida de alta eficiência/detetor de arranjo de diodos (HPLC-DAD) utilizando uma interface de dessorção para SPME e uma fibra sol-gel Carbowax 20M ormosil, produzidas em nosso laboratório. Após avaliação de desempenho da interface e eficiência da fibra sol-gel, uma metodologia de análise foi desenvolvida, avaliando-se os principais parâmetros de validação: sensibilidade, linearidade, faixa linear, exatidão, precisão, limites de detecção e quantificação. No segundo capítulo, tentamos relacionar a composição química de voláteis de plantas analisados por SPME-GC-MS com a atividade antimicrobiana de óleos essenciais. A avaliação dos voláteis foi feita utilizando-se dois tipos de fibras comerciais: PDMS e PDMS/DVB e também pela análise do óleo essencial obtido por métodos tradicionais. A atividade antimicrobiana dos óleos essenciais foi realizada pelo método da concentração mínima inibitória (MIC) com a finalidade de selecionar óleos com potencial terapêutico, em substituição às drogas existentes no mercado. / Abstract: The present work is presented in two chapters that had the scope of developing methodologies for solid phase microextraction coupled to gas and liquid chromatography. The first chapter discusses analysis of organophosphorous pesticides in water soluble samples and plant infusions by High Performance Liquid Chromatography coupled to photodiode array detector (HPLC-DAD) using a SPME desorption interface and Carbowax 20M sol-gel fiber, both produced in lab. After interface and sol-gel fiber efficiency evaluation an analysis method was developed that considered validation parameters: sensibility, linearity, linear range, accuracy, precision, detection limit, and quantification limit. In the second chapter we proposed to establish a relationship among plant's chemical volatile composition analyzed by SPME-GC-MS and antimicrobial activity of essential oils. Two commercial fibers: PDMS and PDMS-DVB were employed for essential oil analysis. Essential oils with potential therapeutic properties in substitution to known commercial drugs were chosen by minimum inhibition concentration experimental model. / Doutorado / Quimica Analitica / Doutor em Ciências
9

Identification and Differentiation of Tier 1 Bacterial Agents Using Gas Chromatography-Mass Spectrometry

Li, Dan 07 June 2013 (has links) (PDF)
A simple method was developed for detection and differentiation of five Tier 1 bacterial agents, including Bacillus anthracis, Francisella tularensis, Yersinia pestis, Burkholderia pseudomallei and Burkholderia mallei as well as their closely related near neighbors by gas chromatography-mass spectrometry (GC-MS). Generally, different classes of compounds can be used as biomarkers for biowarfare agent detection, including nucleic acids (i.e., DNA or RNA), proteins (i.e., antibodies), carbohydrates (i.e., sugars), lipopolysaccharides, lipids (i.e., fatty acids) and small molecules. One-step thermochemolysis (TCM) was developed to provide GC-MS detectable biomarker signatures, including sugars, fatty acids and small molecules. Solid phase micro-extraction (SPME) was used for biomarker extraction, concentration and introduction into the GC-MS. Statistical algorithms were constructed using a combination of biomarkers for the five agents, which were robust against different growth conditions (medium and temperature). A general GC-MS temperature program was developed for all five Tier 1 bacteria. The total analysis time, including TCM, SPME extraction and GC-MS, is approximately 40 min. The total-ion chromatograms are very different for the five species. The final goal of this research was to develop an accurate, fast, simple, robust and automated method for field application. Therefore, an automated sample preparation system was designed, constructed and tested. The system automatically controls the movement of sample vials from one position to another, crimping of septum caps onto the vials, precise delivery of reagents and TCM reaction times and temperatures. The specific operations of introduction of sample vials, SPME sampling, injection into the GC-MS system and ejection of used vials from the system were performed manually in this study, although they can be integrated into the automated system. Manual SPME sampling is performed by following visual and audible signal prompts for inserting the fiber into and retracting it from the sampling port. A rotating carousel design allows for simultaneous sample collection, reaction, biomarker extraction and analysis of sequential samples. Bacillus species were used to test this autoreactor, and 96% of the samples were correctly identified using a statistical algorithm. This research applies not only to the rapid identification of Tier 1 agents after a biological attack, but should also benefit clinical diagnosis, which is essential to effective treatment.
10

\"Análise de fármacos em fluidos biológicos empregando o acoplamento SPME-LC/MS\" / \"Analysis of pharmaceutical compounds in biological fluids using on-line SPME-LC/MS\"

Alves, Claudete 19 April 2006 (has links)
Os métodos convencionais para a determinação de fármacos em fluidos biológicos baseiam-se em técnicas cromatográficas e imunoquímicas. O tratamento prévio de amostras biológicas, o qual abrange as etapas de extração, pré-concentração e “clean-up", tem sido requerido nas análises de fármacos, para aumentar a sensibilidade e seletividade analítica. No entanto, nos últimos anos, com o avanço das técnicas instrumentais, diversas técnicas têm sido avaliados para a análise de diferentes fármacos em fluidos biológicos, destacando-se entre elas a Microextração em Fase Sólida (SPME) e a Cromatografia Líquida acoplada a Espectrometria de Massas (LC/MS). A SPME apresenta uma série de vantagens em relação às técnicas de extração tradicionais, ou seja: não requer instrumentação analítica sofisticada, não utiliza solvente orgânico, permite automação das análises, a reutilização das fibras extratoras e integra em um único sistema, a extração, concentração e introdução da amostra no sistema cromatográfico. Neste trabalho, foi desenvolvida uma interface versátil e de baixo custo, que permite o acoplamento das técnicas SPME-LC/MS para análise dos fármacos antidepressivos tricíclicos e anticonvulsivantes. O planejamento fatorial empregado mostrou ser uma ferramenta estatística importante e simples, sendo obtido mais informações com um número menor de experimentos, avaliando não só os efeitos principais como os efeitos de interação de todas as variáveis nas respostas. As condições cromatográficas otimizadas foram adequadas para a análise por LC/MS. Os níveis de detecção alcançados ressaltam a importância e destaque da técnica de cromatografia líquida de alta eficiência acoplada à espectrometria de massas (LC/MS). O método desenvolvido, tanto para os fármacos antidepressivos tricíclicos como para os anticonvulsivantes, mostrou especificidade, precisão, linearidade e limite de quantificação adequado para a análise. / Conventional methods used for the determination of drugs in biological fluids are based on chromatographic and immunochemical techniques. The biological samples treatment - which includes extraction, pre-concentration and clean up steps – has been required in drugs analysis in order to increase both analytical sensitivity and selectivity. Nevertheless, lately, within the advancements in instrumentation, different techniques have been evaluated for the analysis of different drugs in biological fluids, such as: solid phase microextraction (SPME) and liquid chromatography coupled to mass spectrometry (LC/MS). SPME presents many advantages towards the conventional extraction techniques (soxhlet, LLE and SPE), which include: use of simple analytical instrumentation, analysis automation, reuse of extractor fibers and integration of extraction, concentration and sample introduction in the same chromatographic system. In this work, a versatile and low cost interface was developed, which allows the coupling of SPME-LC/MS techniques to tricyclic antidepressants and anticonvulsivant drugs analysis. The employed factorial design has shown to be a simple and useful statistical tool. With this device more information could be obtained with fewer experiments by evaluating not only the main interaction effects but also the interaction effects of all variables on the results. The optimized chromatographic conditions were adequate for LC/MS analysis. The obtained detection levels highlight the importance of high performance liquid chromatography coupled to mass spectrometry (LC/MS). The developed method, for both tricyclic antidepressants and anticonvulsivants drugs, has presented specificity, accuracy, linearity and adequate limit of detection for this analysis.

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