Variations of gas and plasma density and composition in Earth’s thermosphere and ionosphere are key indicators of interactions between different layers of Earth’s atmosphere. The nature of interactions between neutral and ion species in the upper atmosphere is an active area of study in Heliophysics and there is much to learn about the dynamic relationship between the ionosphere and neutral thermosphere. Mass Spectrometers are among an array of instruments used to explore Earth’s upper atmosphere and other space environments. In the past, data from mass spectrometers flown in low earth orbit has been used to improve atmospheric models and to study the dynamics of the ionosphere and thermosphere. Historically, these instruments are substantial in size and deployed on larger satellite platforms. Data from these larger instruments generally provide information from a specific point in time at a single location. Studies of atmospheric density and composition with multiple locations for each time point could be performed by CubeSat swarms if proper instrumentation were available to fit CubeSat payload restrictions. The proposed miniaturized time-of-flight (TOF) mass spectrometer (MS) will have a mass resolution and range sufficient for measuring the composition of Earth’s thermosphere and ionosphere while operating within the power and space constraints of a CubeSat. The capabilities of this instrument could dramatically reduce the cost of future missions while simultaneously enhancing the science return. The design employs miniaturization of TOF-MS technology, including resolution refinement techniques used for larger instruments and standard concepts for TOF-MS components such as acceleration grids, a Bradbury-Nielsen wire gate, a gridless ion mirror, and microchannel plate detector.

<p> Edible oils consist primarily of triacylglycerols (or TAGs), which are triesters of glycerol and fatty acids. Determination of the TAG compositions of edible oils is becoming more important, given the economic value of these oil products and the increasing incidence of adulterating high quality oils with poorer quality oils. In this study we report the development of an analytical protocol using positive ion infusion electrospray mass spectrometry (ESI/MS) in conjunction with tandem mass spectrometry which affords both identification and quantification of TAGs in edible oils samples.</p> <p> This thesis reports a simple, comprehensive and quantitative method for the analysis of TAGs in edible oils in which the optimized method involves the infusion of an oil sample in chloroform:methanol (1:1) solution (~10-15 μg/mL of oil) in the presence of 0.5 mM LiCl. A sequence of corrections were applied to the raw peak area data of the TAG molecular ions, [M+Li]+, to account for: (1) normalization of peak area data using three internal standards, (2) peak area contributions of M+2 isotopic peaks of TAGs with one more degree of unsaturation and (3) peak area contributions of LiCl adduct ions, [M+Li+LiCl]+, when applicable. The major correction involved multiplication to a given TAG peak area by the appropriate electrospray relative response factor (RRF) for that TAG. The RRFs for all TAGs containing between 48 and 63 carbons in their fatty acyl chains and between 0 and 9 degrees of unsaturation were extrapolated from experimentally determined response factors of a series of standards. The RRFs were found to decrease by 6.7% for each additional acyl chain carbon but increased by 18.6% for each double bond. Comparison of these calculated RRFs to reported RRFs for a series of TAG standards showed an excellent correlation (1.06% ± 10.20% RSD).</p> <p> The use of Li+ in TAG analysis followed from the reports by Hsu and Turk [93] and Han and Gross [18] which showed that Li+ afforded more intense MS, and particularly MS/MS, spectra than either H+ or Na+. The enhanced intensities in MS/MS spectra (determined using a triple quadrupole mass spectrometer) were critical for the identification of TAGs, including the identity of the fatty acyl group located at the sn-2 position. However, this method cannot distinguish unambiguously between isobaric TAGs. This methodology was applied to the profiling of a number of edible oils including canola, olive, sesame, grape seed, walnut and hemp seed oils. The major TAGS in these samples contained 52, 54 and 56 carbons with between 0 and 11 degrees on unsaturation in a given TAG. There were minor amounts of TAGs containing 50, 55 and 57 carbons.</p> <p> The ability of this method to determine quantitatively the number of degrees of unsaturation in an oil sample was tested by examining a series of partially hydrogenated canola oil samples kindly provided by Bunge Canada. Five oil samples derived from a single feedstock with differing numbers of degrees of unsaturation, measured as iodine values, were subjected to our analytical method. The measured iodine values were compared to iodine values calculated from the number of degrees of unsaturation obtained by our MS-based method. The slope of this correlation was 1.10 with an R^2 = 0.995. Overall, this method is much simpler and more accurate than the protocol described by Han and Gross [18]. This methodology will be applied as routine method for the analysis of TAGs in biological samples such as blood samples.</p> / Thesis / Master of Science (MSc)

<p> Lead isotope ratios have been determined by a VG.354 thermal ionization mass spectrometer on Sudbury Igneous Complex sulphide ores. The isotopic ratios are contrasted with the lead isotope profile of selected country rocks in the vicinity of the complex. South Range data form a linear array whose slope indicates an age of approximately 1.85 Ga, the published age of the igneous complex. They also indicate North Range data a magmatic origin for lead in the ore. North Range data describe a parallel isochron, with lower 206Pb/204Pb and 207Pb/204Pb ratios. The South and North Range data are similar to the lead-isotope composition of country rocks close to them, and indicate rather different crustal-source rocks for sulphide ores in these regions of the complex. This fact suggests that the Sudbury Igneous Complex was generated by a meteorite impact which occurred at the edge of the Huronian succession overlying the Southeast edge of the Superior Province. </p> / Thesis / Master of Science (MSc)

Microorganisms with an ability to thrive in harsh environments are referred as “extremophiles”. With advances in biotechnology, interest has grown in the extremophile research because of their unique macromolecules’ characteristics due to their growth environments. Over last decade, researchers have isolated many extremophiles from environments like volcano, salt lakes, hydrothermal vents, deep oceans, Antarctica glaciers etc. Macromolecules of these extremophiles are responsible for their survival in extreme environments. In this research work we have isolated lipid molecules from three different microorganisms. 1) GWE1 strain, a thermophilic bacterium, isolated from dark crusty material from sterilization ovens. 2) 7L strain, a thermophilic bacterium, isolated from Chilean Copahue Volcano. 3) I1P strain, a facultative anaerobe of the family Enterobacteriaceae, recently isolated from Antarctica. Complex lipid arrangement and/or type in the cell membrane are known to affect thermostability of microorganisms and efforts were made to understand the chemical nature of the polar lipids of membrane. In this work, we extracted total lipids from cell membrane, separated them by TLC into various fractions and characterize the lipid structures of fractions with analytical tools such as 1H, 13C, 31P and 2D NMR spectroscopy, ATR-FTIR spectroscopy and MSn spectrometry. In GWE1 strain, we were able to identify glycerophosphoethanolamine, glycerophosphate, glycerophosphoglycerol and cardiolipin lipid classes and an unknown glycerophospholipid class with novel MS/MS spectra pattern. We have also noticed the presence of saturated iso-branched fatty acids with NMR spectra in individual lipid classes. In case of I1P strain, we have identified glycerophosphoglycerol, glycerophosphoethanolamine, glycerophosphate, and acyl glycerophosphoglycerol lipid classes with unsaturated fatty acids in their structure, which could be one of the many reasons for survivability at lower temperatures. In case of 7L strain, we were able to identify glycerophosphoglycerol, cardiolipin, glycerophosphoethanolamine and glycerophosphate lipid classes with saturated iso branched fatty acids. FAME analysis revealed iso-15:0 (52.29 %) and iso-17:0 (18.64 %) as major fatty acyl chains. We did not observe major difference in polar head group composition of lipid classes between thermophiles (GWE1 and 7L) compare to psychrophiles (I1P). Major difference among these three strains was in fatty acid composition of lipid molecule. Both thermophiles showed presence of lipids with long chain saturated fatty acids while I1P showed presence of lipid molecule with unsaturated fatty acid chain. Lipids made of unsaturated fatty acids have lower melting points and they introduce kink in the cell membrane structure. At lower temperatures, these effects allow membrane to maintain fluidity and its functionality, which in turn allows the microorganism to grow at lower temperature. Lipids made with saturated iso branched fatty acid chain have higher melting points and they pack together densely in cell membrane. At high temperature because of higher melting point and dense packing, membrane fluidity is not affected and this effect allows microorganism to grow at the higher temperature. We believe that change in fatty acid composition is one of the many reasons for these microorganisms to survive the extreme condition. Thermostability of the other macromolecules (DNA, enzyme) of these extremophiles is not studied in this dissertation. / Chemistry

The cylindrical ion trap (CIT) is made up of two planar endcap electrodes and a cylindrical ring electrode. The investigation of simpler geometries like CIT has been started off in recent years with a view towards miniaturization. As a step towards this, numerical studies on CITs were carried out in our laboratory. Here in this study, our motive is to characterize a CIT through experiments. We have designed a mass spectrometer where a CIT is used as the mass analyzer. The trap performance was observed by varying six parameters associated with our experiment. The parameters are (1) the ionization voltage, (2) the ramp time, (3) the ionization time, (4) the cooling time, (5) the dead time and (6) the bias voltage applied across the filaments. All the experiments have been performed in the mass selective boundary ejection mode.

The thesis aims at building an experimental setup for conducting the boundary ejection and resonance ejection experiments on wide variety of ion trap mass analyzers. The experimental setup has two parts namely power electronics circuits and mechanical assembly. The focus of the thesis is on the electronics hardware which provides various power sources required for the operation of ion trap mass spectrometer. The electronics circuits discussed in the thesis have better performance, flexibility and ruggedness compared to the existing setup. The traditional power supplies used in ion trap mass spectrometers are all linear supplies. But one major drawback of these supplies is the high power dissipation and consequently, the power efficiency degrades. We are trying to introduce switch mode power supplies to reduce the power dissipation loss and eventually increase the power efficiency. In the course of the work the following power supplies have been developed. The supplies are - 1.Constant current source, 2.Filament base, 3.gating power supply and pulsing circuit, 4.High voltage DC power supply and 5. High voltage RF generator.

Orientador: Marcelo Alexandre Prado / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-21T09:52:53Z (GMT). No. of bitstreams: 1 MirandaeSilva_LigiaMaria_M.pdf: 148256 bytes, checksum: 789cac2002bb2e8dcb1bf70832d395b6 (MD5) Previous issue date: 2012 / Resumo: O crescente aumento populacional em escala mundial, tornou necessário um grande esforço por parte da agricultura para aumentar, a cada ano, a produção de alimentos para atender as necessidades do mercado externo e interno do Brasil. Recursos técnicos e científicos passaram então, a serem aplicados em busca da melhoria na produção dos cultivos,principalmente mediante o uso de fertilizantes e praguicidas. Com isso, a sociedade se deparou com problemas de ordem de equilíbrio ambiental e saúde pública, pois devido à contínua diversificação dos fitoparasitas, surgem, a todo momento, reduções do período de tempo entre aplicações consecutivas, e mais importante talvez, usos de doses mais altas e emprego simultâneo de diferentes pesticidas, por parte dos agricultores, objetivando complementar ações específicas ou alcançar efeitos sinérgicos para maiores rendimentos na produção. Tal situação traz como conseqüência óbvia e direta, o aumento, inaceitável, dos riscos de contaminação do meio ambiente com resíduos químicos de defensívos da área agropecuarista prejudiciais à saúde, o que leva a inúmeros problemas relativos à segurança alimentar dos produtos consumidos, e à uma preocupação de âmbito nacional evidenciada pela criação do Programa de Análise de Resíduos de Agrotóxicos em alimentos (PARA) da ANVISA. O aumento na necessidade de detecção e quantificação destes compostos, acarretou o desenvolvimento de pesquisas no setor, a fim de atingir uma melhoria na eficiência,qualidade e rapidez de resposta nas análises. A possibilidade do estudo de não apenas um de cada vez, mas de até 300 compostos sendo extraídos, detectados e quantificados simultâneamente se tornou a saída mais viável, tanto qualitativa quanto economicamente, facilitando o monitoramento contínuo do fornecimento de produtos do setor alimentício pelos chamados métodos multiresíduos. O presentre trabalho teve como princípio a validação de um método multiresíduo para análise de 14 analitos usando uma técnica de alto poder de concentração e limpeza do extrato como o GPC (Gel Permeation Chromatography) e detecção e quantificação por GC-MS/MS e LC-MS/MS. Os pesticidas investigados englobam classes como: acaricidas, inseticidas, fungicidas, nematicidas e formicidas de aplicação foliar, em sementes ou em solo, sendo que o acefato, metamidofós, acetamiprido e o thiamethoxan foram extraídos de amostras de batata e feijão e analisados por LC-MS/MS e a azoxistrobina, bifentrina, carbofuran, chlorotalonil, clorpirifós, clorfenapir, etofenprox, famoxadone,metalaxil, procimidone e o tebuconazole em amostras de batata e tomate e analisados por GCMS/MS. Os limites de detecção (LD) encontrados variaram de 0,06 a 2,89µg/L, e os coeficientes de variação (CV), de 0,036 a 2,036%. As recuperações foram determinadas em cada tipo de amostras, e os valores encontrados estavam entre 93,34% e 109,67%. Nenhuma das matrizes utilizadas apresentaram resultados insatisfatórios e o método utilizado mostrouse robusto e de fácil aplicação para todos os analitos testados / Abstract: The growing population worldwide, has required a great effort on the part of agriculture to increase each year, the production of food to meet the needs of external and internal market of Brazil. Technical and scientific resources spent then, to be applied in pursuit of improved crop production, mainly through the use of fertilizers and pesticides.With this, the company encountered problems in the balance of environmental and public health, since due to the continuous diversification of plant parasites, arise at any moment,reductions in the time period between consecutive applications, and perhaps most important,uses more doses high and simultaneous use of different pesticides by farmers, aiming to complete specific actions or to achieve synergistic effects in producing higher yields. This situation brings obvious and direct consequence, the increase unacceptable risk of environmental contamination with chemical residues from pesticides in farms are harmful to health, which leads to numerous problems relating to food safety of the products consumed, and to a concern nationwide evidenced by the creation of the Program Analysis of Pesticide Residues in Food (TO) of ANVISA. The increase in the necessity for detection and quantification of these compounds, led the development of research in the sector in order to achieve an improvement in efficiency, quality and responsiveness in the analyzes. The possibility of studying not just one at a time, but up to 300 compounds being extracted,detected and quantified simultaneously output became more viable, both qualitatively and economically, facilitating continuous monitoring of the supply of products by the food industry called methods multiresidue. The principle presentre work was the validation of a multiresidue method for analysis of 14 analytes using a technique of high power concentration and cleanup of the extract as GPC (Gel Permeation Chromatography) and detection and quantification by GC-MS/MS and LC- MS / MS. The pesticides investigated include classes such as acaricides, insecticides, fungicides, insecticides and nematicides foliar, seed or soil,and acephate, methamidophos, and Acetamiprid thiamethoxan were extracted from samples of potatoes and beans and analyzed by LC-MS / MS and azoxystrobin, bifenthrin, carbofuran,chlorothalonil, chlorpyrifos, chlorfenapyr, etofenprox, famoxadone, metalaxyl, procymidone and tebuconazole in samples of potato and tomato and analyzed by GC-MS/MS. The limits of detection (LOD) ranged from 0.06 to 2.89 mg / L, and the coefficients of variation (CV), 0.036 to 2.036%. The recoveries were determined for each type of samples, and the values were between 93.34% and 109.67%. None of the arrays used had unsatisfactory results and method proved to be robust and easy to apply for all analytes tested / Mestrado / Ciência de Alimentos / Mestra em Ciência de Alimentos

Analysis and characterisation of biomolecules using mass spectrometry has advanced over the past decade due to improvements in instrument design and capability; relevant use of complementary techniques; and available experimental and in silico data for comparison with cutting-edge research. This thesis presents ion mobility data, collected on an in-house modified QToF mass spectrometer (the MoQTOF), for a number of protein systems. Two haemoproteins, cytochrome c and haemoglobin, have been characterised and rotationally-averaged collision cross-sections for a number of multimeric species are presented. Intact multiply-charged multimers of the form [xCyt c + nH]z+ where x = 1 (monomer), x = 2 (dimer) and x = 3 (trimer) for cytochrome c have been elucidated and for species with x ≥ 2, reported for the first time. Fragment ions possibly attributed to a novel fragmentation mechanism, native electron capture dissociation, are reported with a brief discussion into their possible production from the dissociation of the gas-phase dimer species. Haemoglobin monomer globin subunits, dimers and intact tetramer have been successfully transferred to the gas phase, and their cross-sections elucidated. Comparisons with in silico computational data have been made and a discussion of the biologically-active tetramer association/dissociation technique is presented. Three further proteins have been studied and their gas-phase collision cross-sections calculated. Two regions of the large Factor H (fH) complement glycoprotein, fH 10-15 and fH 19-20, have been characterised for the first time by ion mobility-mass spectrometry. Much work using nuclear magnetic resonance spectroscopy has previously been achieved to produce structural information of these protein regions, however further biophysical characterisation using mass spectrometry may aid in greater understanding of the interactions these two specific regions have with other biomolecules. The DNA-binding core domain of the tumour suppressor p53 has been characterised and cross-sections produced in the presence and absence of the zinc metal ion that may control the domain’s biological activity. Within this core domain, p53 inactivation mutations have been shown to occur in up to 50% of human cancers, therefore the potential exists to further cancer-fighting activity through research on this region. Anterior Gradient-2 (AGR2) protein facilitates downregulation of p53 in an as yet unclear mechanism. Recent work using peptide aptamers has demonstrated that this downregulation can be disrupted and levels of p53 restored. Collision cross-sections for six peptide aptamers have been calculated, as well as cross-sections for multimers of AGR2 protein. A complex between one aptamer with the protein has also been elucidated. Use of the commercially available Synapt HDMS ion mobility-mass spectrometer at Waters MS Technologies Centre (Manchester, UK) allowed data to be collected for both Factor H protein regions and for the DNA-binding core domain of p53. Data are compared in the appropriate chapters with data collected using the MoQTOF.

A presença de nove ésteres (acetato de etila, butanoato de etila, hexanoato de etila, lactato de etila, octanoato de etila, nonanoato de etila, decanoato de etila, octanoato de isoamila e dodecanoato de etila) foi investigada por cromatografia gasosa hifenada à espectrometria de massas via injeção direta de amostras (ID-CG-EM). Cento e trinta e seis amostras de aguardente de cana foram coletadas durante sua destilação em diferentes produtores em diferentes cidades localizadas no interior do estado de São Paulo. Também foram analisadas 21 amostras de cachaça comercial, 10 amostras de rum e 10 amostras de uísque importados e obtidos em lojas \"duty free shop\". A metodologia analítica desenvolvida para análise de ésteres demonstrou-se apropriada para a determinação destes compostos em bebidas destiladas, sendo simples (injeção direta), seletiva e relativamente rápida. Apresentou baixos limites de detecção e quantificação e boa repetibilidade. O acetato de etila é o principal éster presente nas bebidas destiladas seguido pelo lactato de etila. Em todas as amostras de bebidas destiladas analisadas neste trabalho foi detectada a presença do éster lactato etila. A presença deste éster está relacionada com a contaminação do mosto por bactérias (Lactobacillus spp) responsáveis pela fermentação láctica. A concentração de lactato de etila nas amostras de cachaça e rum é muito superior à encontrada nas amostras de uísque. A análise multivariada dos resultados analíticos aplicada ao banco de dados dos ésteres juntamente com as concentrações de carbamato de etila e benzaldeído levaram à formação de dois grupos bem distintos: amostras destiladas em alambiques de cobre e amostras destiladas em colunas de aço inox. Os modelos estatísticos gerados pelas análises exploratórias de PCA, PLS e LDA utilizando o carbamato de etila, benzaldeído, decanoato de etila e o dodecanoato de etila como discriminantes revelaram ser possíveis a diferenciação entre estes dois grupos de destilados com uma porcentagem de acerto de 81% para PCA, 78,4 % para a PLS e 97,6% para LDA. Os métodos cromatográficos sugeridos pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA) para a determinação de ésteres não englobam o monitoramento do lactato de etila, subestimando o resultado final. / The presence of nine esters (ethyl acetate, ethyl butanoate, ethyl hexanoate, ethyl lactate, ethyl octanoate, ethyl nonanoate, ethyl decanoate, isoamyl octanoate, and ethyl dodecanoate) was investigated by gas chromatography hyphenated to a mass spectrometry through sample direct inject (DI-GC-MS). One hundred and thirty six sugar cane spirits collected immediately after its distillation from different producers and different cities located in the countryside of São Paulo state. Also, it was analyzed 21 commercial samples of cachaça, 10 samples of rum and 10 samples of whiskey imported and purchased from the duty free shop. The analytical method applied to esters analysis was appropriated for the determination of these compounds in distilled spirits, since it is simple (direct inject), selective and reasonably fast. It presented low detection and quantification limits and good reproducibility. Ethyl acetate is the main ester present in the distilled spirits followed by ethyl lactate. Ethyl lactate was detected in all the distilled beverage samples analyzed herein. The occurrence of this ester is related to bacterial contamination of must (Lactobacillus spp) responsible for the lactic fermentation. The ethyl lactate content in cachaça and rum samples are superior that presented by whiskey samples. The multivariate analysis of the analytical results applied to the esters data set jointly with the content of ethyl carbamate and benzaldehyde lead to the clustering of two quite distinct groups: sugar cane spirits distilled in copper alembic and sugar cane spirits distilled in stainless steel column. The resulting statistical model generated by PCA, PLS and LDA exploratory analysis employing ethyl carbamate, benzaldehyde, ethyl decanoate, and ethyl dodecanoate as discriminators was able to distinguish between these two groups with a accuracy of 81 % for PCA, 78,4 % for PLS and 97,6 % for LDA. The chromatographic method recommended by the Ministério da Agricultura, Pecuária e Abastecimento (MAPA) for the esters determination does not include the monitoring of ethyl lactate leading to a underestimating of the final result.

De nouvelles méthodes de détection et de quantification du VX (O-éthyl S–(2(diisopropylamino)éthyl) (méthylphosphonothioate)) dans le plasma par chromatographie liquide couplée à un spectromètre de masse en tandem (LC-MS/MS) ont été développées. Après avoir été mise en œuvre en milieu HBSS (rendement > 99%), la méthode d'extraction liquide-liquide de notre composé d'intérêt nous permet d'obtenir en milieu plasmatique un rendement de soixante-cinq pour cent (65%). Cette méthode d'extraction permet d'évaluer la présence de VX dans de très faibles volumes d'échantillons de plasma (entre 20 et 1000 µL), donc dans des volumes compatibles avec des expérimentations sur de petits rongeurs. Cette extraction est suivie d'une analyse par LC-MS/MS en phase 100% organique. Des limites de détection de 0,15 et 0,5 pg/mL (pour 5 µL injecté) sont obtenues respectivement avec l'utilisation de la colonne Allure Biphényl (Restek) et Lux Cellulose-1 (Phenomenex). Afin d'étudier la toxicocinétique des énantiomères du VX dans le plasma, nos recherches se sont ensuite focalisées sur la séparation de ces derniers. Des résultats prometteurs ont été obtenus en utilisant une colonne Lux cellulose-2 (Phenomenex). / Innovative analytical methods have been developed to detect and quantify the organophosphorus nerve agent, VX (O-ethyl S–(2(diisopropylamino)ethyl) (methylphosphonothioate)), in plasma using liquid chromatography coupled with mass spectrometry (LC-MS/MS) technique. Liquid-liquid extraction of VX from HBSS environment was achieved with excellent yields (> 99%). Next, extraction from plasma was performed and generated a recovery rate of approximately sixty-five percent (65%). Our distinctive extraction methodology was implemented to evaluate the presence of VX in very small quantities of plasma (between 20 to 1000 µL) as in small rodents' experiments. It was followed by an LC-MS/MS analysis in a 100% organic phase. A Lux Cellulose-1 column (Phenomenex) and an Allure biphenyl column (Restek) were tested with detection limit at 0.15 pg/mL and 0.5 pg/mL in plasma (5 µL injected), respectively. Finally, our study was focused on the separation of VX enantiomers and hopeful results were provided using a Lux cellulose-2 column (Phenomenex).