A new era of high-throughput mass spectrometry emerged with the nearly simultaneous introduction of two ambient ionization techniques: desorption electrospray ionization (DESI) and direct analysis in real time (DART). The ability to integrate near instantaneous sample analysis with the specificity of mass spectrometry opened up a broad range of applications. While some of these involve the direct analysis of bulk materials, many others require the collection and deposition of samples onto suitable substrates. This dissertation details the development of a new mode of operation for DESI. Instead of depositing a sample onto a continuous surface, the sample is either collected by or deposited onto a mesh substrate. Analytes either adsorb to the mesh strands or become suspended within the confines of the mesh in macroscale droplets. The samples are then analyzed by scrolling the mesh orthogonally into the path of an electrospray plume positioned coaxial to the inlet capillary of the mass spectrometer, thereby resulting in the transmission of the ionizing plume directly through the material. The transmission mode results in desorption and ionization typical of DESI, but with the added benefits of a simpler experimental geometry and the convenient analysis of both dry (i.e., following evaporation of the deposition solvent) and wet (i.e., solvated) samples. The simplification of the experimental arrangement increases method robustness and reproducibility, while the inclusion of a mesh substrate introduces new possibilities for sample collection and introduction, due to the intricate chemistry between the mesh material, analytes, and deposition/electrospray solvent system. However, the most important benefit lies in the development of surface-enhanced TM-DESI, whereby mesh substrates are derivatized to specifically capture and concentrate targeted analytes directly from solution. Following removal of matrix interferences by sample rinsing and subsequent cleavage of a photolabile linker, the mesh is analyzed directly by TM-DESI-MS. The technique has the potential to overcome interferences that have typically required chromatographic separations using LC-MS or have been insurmountable using ambient ionization methods. The impact of the surface-enhanced method could be tremendous as it may ultimately unite the competing metrics of analytical speed and specificity for ambient ionization mass spectrometry. / text

A química de produtos naturais da família Asteraceae tem sido foco de estudo do Núcleo de Pesquisa em Produtos Naturais e Sintéticos (NPPNS) da FCFRP-USP que relatou diversas novas moléculas, com destaque para a classe das lactonas sesquiterpênicas. Para essas substâncias já foram atribuídas diversas atividades farmacológicas tais como antioxidante, anti-inflamatória, antimicrobiana, analgésicas e tripanossomicida. A atividade antitumoral da lactona sesquiterpênica goyazensolido (GOYA) foi avaliada no NPPNS e esse estudo revelou uma atividade farmacológica interessante paras as linhagens de tumor cutâneo e cerebral. Com isso, viu-se nesta classe de substâncias uma oportunidade para explorar o potencial antitumoral assim como sua distribuição e metabolismo. Para compreender melhor a distribuição dessa substância na pele, o modelo in vitro de penetração utilizando células de Franz e pele de orelha de porco como membrana foi aplicado. Para esse estudo um método de geração de imagem MALDI-MSI para avaliação da distribuição do GOYA na pele, assim como, um método por UPLC-MS/MS foram desenvolvidos. Para o desenvolvimento e validação do método de MALDI-MS as substâncias doxorrubicina e minoxidil, com estudos de penetração já estabelecidos, foram utilizadas. Para avaliação da distribuição de GOYA em sistema nervoso central (SNC) um modelo em insetos, utilizando gafanhotos foi aplicado. Nesse experimento os gafanhotos receberam a dose de 500 ?M de GOYA, e foram coletadas amostras de hemolinfa, fezes e cérebro nos tempos de 15 e 30 minutos, assim como amostras de gafanhoto total. Para determinação de GOYA nas amostras de gafanhoto um método quantitativo por UPLC-MS/MS e um método de geração de imagem por DESI-MSI foram desenvolvidos. Com os estudos de penetração cutânea pudemos concluir que MALDI-MSI foi capaz de confirmar a distribuição de minoxidil nas amostras de pele, no entanto, não se mostrou uma técnica eficaz para determinação de doxorrubicina. A técnica de MALDI-MSI, em adição ao método de UPLC-MS/MS foi capaz de revelar que o GOYA não penetrou na pele estando acumulado na sua camada superior, provavelmente no estrato córneo. Nos ensaios de distribuição em SNC foi possível observar através do método de UPLC-MS/MS que o GOYA está presente no cérebro, hemolinfa e fezes do gafanhoto. Com isso podemos concluir que o modelo utilizado é um bom modelo de predição de permeação a barreira-hematoencefálica, bem como para estudos de metabolismo. Conclui-se também que o método desenvolvido para essa finalidade foi adequado. A técnica de DESI-MS apesar de não gerar resultados positivos para permeação cerebral revelou a presença de GOYA no intestino do animal no tempo de 30 minutos, o que caracteriza uma rápida eliminação de GOYA do organismo / The Natural Products\' Chemistry has been the focus of the \"Núcleo de Pesquisa em Produtos Naturais e Sintéticos\"(NPPNS) at School of Pharmaceuthical Science of Ribeirão Preto, University of São Paulo (FCFRP- USP). NPPNS reported a variety of unknown molecules from Asteraceae family, highlighting the sesquiterpene lactones (STL). STL showed important pharmacological activities, such as antiinflammatory, antimicrobial, analgesic and trypanossomicide. The STL goyazensolide (GOYA) exhibit antitumor activity for skin and central nervous system (CNS) cancer cell lines . With that the research group saw in this class of compounds a chance to explore the antitumor potential as well as unveil its distribution and metabolism. For a better understanding of the distribution of this compound in the skin, the Franz cell in vitro model using ear pig skin was applied. For that, a MALDI-MSI method was developed to assess the distribution of GOYA in the skin, along with a UPLC-MS/MS method, to confirm the results. In order to develop and validate a MALDI-MSI method, doxorubicin and minoxidil, known substances in the cutaneous penetration studies, were used. An insect model with locust was applied for the investigation of GOYA distribution in CNS. The locust received a 500 ?M GOYA dose and hemolymph, brain and feces samples were collected in 15 and 30 minutes, as well as the entire locust. In order to assess GOYA in the locust samples, an UPLC-MS/MS method was developed, and for distribution in the entire locust a DESI-MSI was developed. The MALDI-MSI method developed for cutaneous penetration study was able to confirm the results for minoxidil experiments and allowed us to see the distribution of this compound in the skin. Unfortunately for doxorubicin MALDI-MSI by the is source analythe dissociation. The MALDI-MSI and the UPLC-MS/MS was able to show that GOYA does not permeate the skin, but is in the skin, probably interacting with the stratum corneum barrier. In the CNS studies we could see through the UPLC-MS/MS method that GOYA is present in the brain, hemolymph and feces in the in vivo model. With that we can conclude that the in vivo insect model is a good alternative for the metabolism and blood-brain-barrier studies. Also we can conclude that, although the DESI-MSI technique was not suitable for CNS permeation studies, it can be applied for metabolism studies, as it revealed the presence of GOYA in the intestine with a 30 minutes experiment, what characterizes a fast distribution and elimination of GOYA in the living organism

Nano-DESI Mass spectrometry imaging of eicosanoids in mouse kidney tissue using selected ion monitoring. Nano-DESI mass spectrometry imaging (MSI) is a technique for label-free spatial and molecular characterization of surfaces and biological samples. Eicosanoids are lipid mediators derived from eicosapolyenoic acid- products of arachidonic acid oxidation. Eicosanoids have been of interest to the medical field for many years. Major focus on this lipid class came from the development of nonsteroidal anti-inflammatory drugs (NSAIDs), some of these including aspirin, naproxen, ibuprofen, and acetaminophen work by blocking either the formation or the effects of eicosanoids. These lipids also play important roles in various body functions (cardiovascular, renal, gastrointestinal, neuronal) and as mediators of inflammation, asthma, fever, pain, hypertension, and stroke. Typically, eicosanoids occur in subnanomolar concentrations, despite their high level of bioactivity, which makes them significantly more difficult to analyze via direct mass spectrometry. Here, selected ion monitoring (SIM) is used to increase the signal-to-noise of the identified eicosanoids compared to a broadband full scan mode.

A derivatization method is applied to chemically modify the glucose molecules. Then the derivatized C1 and C2 labeled glucose can be differentiated by tandem mass spectrometry. A multiple reaction monitoring method is developed to quantify the C1- and C2-13C labeled glucose, with deuterated glucose as the internal standard.Based on the fragmentation of cross-linked amino acids (pyridinoline (PYD) and deoxypyridinoline (DPD)), a precursor ion scan method is developed to detect DPD and PYD from a complex matrix. DPD is detected in a hydrolyzed mouse ventricle collagen sample by this method.A series of peptides and proteins are successfully ionized by a home made DESI source. The investigation of the sample surface effect shows that self assembled monolayer surfaces produce better signal than bare gold surfaces, implying that this is due to the lower electron transfer on SAM film which allows more ions to survive.

No description available.

Chemical imaging by mass spectrometry is a powerful approach by which to map spatial distributions of molecules to better understand their function in the system of interest. Over the last thirty years, MSI has evolved into a very powerful analytical tool for the investigation of chemically-complex samples including biological tissues, catalytic surfaces and thin layer chromatography plates, among many others. The work in this dissertation aimed to characterize existing MSI methods, while also developing novel instrumentation able to overcome the challenges found in a variety of applications. Different sample preparation and ionization techniques were evaluated to maximize detection of lipid species in brain tissues subjected to traumatic injury to better understand the biological processes involved. Next, differential mobility separation was coupled to an ambient MSI system that resulted in increased signal-to-noise ratios and image contrast. Third, bulky catalytic granite surfaces were imaged to determine specific mineral reactivity and demonstrate the ability of desorption electrospray ionization to image such samples. Fourth, a novel technique was developed names Robotic Plasma Probe Ionization (RoPPI), which uses a vision system-guided robotic arm to probe irregular surfaces for three dimensional surface imaging. Finally, a software program was developed to automatically screen MSI datasets acquired from thin layer chromatography separations for spot-like shapes corresponding to mixture components; this program was named DetectTLC. This research resulted in instrumentation advances for MSI that have enabled increased chemical diversity, enhanced sensitivity and image contrast, imaging of bulky or irregularly-shaped surfaces, and multivariate tools to facilitate data interpretation.

Desorption electrospray ionization (DESI) is an ambient ionization technique used for mass spectrometric imaging of biological samples. When coupled with isotopic ratio measurements of deuterium-labeled tissues, DESI provides a means of measuring metabolic rates on a spatially resolved basis. In vivo metabolic rates are desired to better understand diseases such as Alzheimer's, Parkinson's, Huntington's, and various forms of cancer that negatively impact metabolic rates within different organs of the human body. Although DESI has been used to image lipids and metabolites of a variety of tissues and other imaging techniques, such as NIMS, have been used to study kinetic turnover rates, DESI has not yet been used to study in vivo metabolic rates using deuterium labeled tissue. This thesis describes how we optimized our DESI source for imaging of biological tissue, how we developed a MATLAB graphical user interface (GUI) to process and interpret the large mass spectral data files, how we conducted our initial mouse brain study for proof-of-concept, and how we plan to implement our DESI imaging in a study with mouse models of Alzheimer's disease. Our initial mouse brain study involved labeling mice with deuterium enriched water, preparing tissue slices for DESI analysis, imaging the tissue slices using DESI coupled with a Bruker mass spectrometer, analyzing the mass spectral data using our custom-designed image_inspector program, confirming identification of lipids using MS/MS, and creating incorporation curves to measure in vivo metabolic rates.

Orientadores: Marcos Nogueira Eberlin, Maria Izabel Maretti Silveira Bueno / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-27T15:37:04Z (GMT). No. of bitstreams: 1 Schwab_NicolasVilczaki_D.pdf: 3814064 bytes, checksum: 830504748a20c22da41317192a1c7d9b (MD5) Previous issue date: 2015 / Resumo: O atual avanço na tecnologia em instrumentação analítica permite análises químicas cada vez mais rápidas e eficientes. Assim, o desenvolvimento de métodos que consistem em minimizar ou eliminar o preparo de amostra apresentam um grande diferencial em relação aos procedimentos tradicionais. Duas técnicas se destacam nesse sentido: a espectrometria de massas com ionização ambiente e a fluorescência de raios X por dispersão em energia. Com características distintas, essas técnicas abrangem um enorme campo de aplicações na ciência. Seguindo este conceito, esta tese de doutorado está dividida em três partes, que ilustram as diferentes aplicações utilizando uma das técnicas mencionadas. Primeiramente, foi relatada a produção e caracterização de superfícies funcionalizadas à base de silício poroso, como substrato para espectrometria de massas com ionização ambiente por dessorção via electrospray (DESI-MS). Os resultados encontrados mostraram que estas superfícies são excelentes alternativas como substrato para análises em DESI-MS, levando a baixos limites de detecção, eliminação de problemas referentes à contaminação cruzada e melhora na estabilidade do sinal analítico. O capítulo seguinte descreve o desenvolvimento de uma fonte portátil para ionização ambiente de moléculas por espectrometria de massas, que elimina a necessidade do uso de cilindros de gás e bombas injetoras. Sua eficiência foi comprovada por meio de análises de diversos compostos, gerando expectativas futuras para aplicações em campo, para resolução de casos analíticos conjuntamente com uso de equipamentos miniaturizados de espectrômetros de massas. Na parte final, foi demonstrado o uso da técnica de fluorescência de raios X na filatelia. Trata-se de uma técnica não destrutiva, onde, obteve-se o perfil elementar característico de diversas amostras de selos postais antigos como, por exemplo, os elementos relacionados à composição das tintas utilizadas na impressão. Como consequência, essa metodologia pode ser utilizada na discriminação em casos de falsificação de peças raras / Abstract: The advancement in analytical instrumentation allows today faster and more efficient chemical analysis. The development of new methods with regards to minimize or eliminate sample preparation steps has a great advantage over traditional procedures. Two techniques stand out in this concept: the ambient ionization mass spectrometry and energy dispersive X-ray fluorescence. With different characteristics, both techniques cover a huge range of applications in analytical chemistry. Following this idea, this thesis is divided into three parts that demonstrates some applications using the techniques mentioned earlier. The first chapter describes the production and characterization of functionalized porous silicon surfaces as substrates for desorption ionization electrospray mass spectrometry (DESI-MS). The results showed that specific surfaces provides an excellent alternative for spot analysis in DESI-MS, increasing detectability, eliminating cross-contamination problems and improving the analytical signal stability. The next chapter reports the development of a portable ambient ionization source for mass spectrometry, which eliminates the use of gas cylinders and injection pumps. Its efficiency was confirmed by analysis of several compounds leading to prospects for field applications; using for example with miniaturized mass spectrometers. Finally, the last chapter demonstrates the use of X-ray fluorescence in philately. The method developed is nondestructive and is a suitable technique to detect elements related with the composition of inks that are used to print stamps. For this reason, this is a powerful methodology to identify counterfeit samples of rare stamps mainly / Doutorado / Quimica Analitica / Doutor em Ciências

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-07-25T12:53:59Z No. of bitstreams: 2 Tese - Aline Pereira Moraes - 2017.pdf: 5958230 bytes, checksum: 799ef005b7ec97bfd8fd06e0e7f3a36b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-26T11:58:55Z (GMT) No. of bitstreams: 2 Tese - Aline Pereira Moraes - 2017.pdf: 5958230 bytes, checksum: 799ef005b7ec97bfd8fd06e0e7f3a36b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-26T11:58:55Z (GMT). No. of bitstreams: 2 Tese - Aline Pereira Moraes - 2017.pdf: 5958230 bytes, checksum: 799ef005b7ec97bfd8fd06e0e7f3a36b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-04-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Palicourea and Psychotria (Rubiaceae) are known for the presence of compounds with potential biological activity, such as the indole alkaloids, flavonoids and norisoprenoids. In order to increase the chemical knowledge of Palicourea species, the phytochemical study of the aerial parts of Palicourea officinalis was carried out for the first time, through the isolation by chromatography and structural elucidation of the compounds by NMR and mass spectrometry. The following secondary metabolites were identified: the novel alkaloid 18-epi-brachycerine; the norisoprenoids: guettardionoside, 3-oxo--ionol 9-O--D-apiofuranosyl-(1®6)--D-glucopyranoside, vomifoliol 9-O--D - apiofuranosyl-(1®6)--D-glucopyranoside and 7,8-dihydro-vomifolol 9-O--D-apiofuranosyl-(1®6)--D-glucopyranoside; the lignan syringaresinol--D-glucoside; the pyrazines 2,5-deoxyfructosazine, 2,6-deoxyfructosazine and fructosazine; the flavonoids quercetin 3-O-sophoroside and kampferol 3-O-sophoroside; 3-caffeoyl and 4-caffeoylquinic acids; feruloylquinic acids; salicylic acid; coumarin scopoletin; besides ursolic and oleanolic triterpenes acids and glycosylated sitesterol and stigmasterol steroids. In addition, for the first time, the indirect and direct DESI-MSI techniques were applied in the study of the spatial distribution of alkaloids in the leaves of Palicourea coriacea and Psychotria prunifolia. The indirect approach was applied successfully and showed distinct distribution patterns of the alkaloids detected. The image data were confirmed by LC-MS. / Palicourea e Psychotria (Rubiaceae) são gêneros conhecidos pela presença de compostos com potencial atividade biológica, tais como os alcaloides indólicos, flavonoides e norisoprenoides. Com o objetivo de ampliar o conhecimento químico de espécies de Palicourea, foi realizado pela primeira vez o estudo fitoquímico das partes aéreas de P. officinalis, através do isolamento por cromatografia e elucidação estrutural dos compostos por RMN e espectrometria de massas. Os seguintes metabólitos secundários foram isolados e identificados: o alcaloide inédito 18-epi-braquicerina; os norisoprenoides: guettardionosídeo e 3-oxo--ionol 9-O--D-apiofuranosil(1”®6’)- -D-glicopiranosídeo e a mistura vomifoliol 9-glicopiranosídeo, vomifoliol 9-O--D-glucopiranosil-(1®6)--D-apiofuranosídeo e 7,8-diidro-vomifoliol 9-O--D-glucopiranosil-(1®6)--D-apiofuranosídeo; a lignana siringaresinol-4’--D-glicosídeo; a mistura de pirazinas 2,5-desoxifructosazina, 2,6-desoxifructosazina e fructosazina; os flavonoides quercetina 3-O-soforosídeo e canferol 3-O-soforosídeo; os ácidos clorogênicos 3-cafeoil e 4-cafeoil-quínicos; uma mistura de ácidos feruloil-quínicos; ácido salicílico; a cumarina escopoletina; além das misturas dos triterpenos ácidos ursólico e oleanólico e dos esteroides sitosterol e estigmasterol glicosilados. Além disso, pela primeira vez, as técnicas de produção de imagem química por DESI-MS direto e indireto foram aplicadas no estudo da distribuição espacial dos alcaloides nas folhas de Palicourea coriacea e Psychotria prunifolia. O método indireto apresentou melhores resultados, com distintos padrões de distribuição dos alcaloides detectados. Os dados da imagem foram confirmados por LC-MS.

Thesis (M.A.)--Miami University, Dept. of History, 2008. / Title from first page of PDF document. Includes bibliographical references (p. 26-31).