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

Historic dye analysis : method development and new applications in cultural heritage

Troalen, Lore Gertrud January 2013 (has links)
A review of the main natural dyes (particularly yellow flavonoids and red anthraquinones) and proteinaceous substrates used in Historical Tapestries and North American porcupine quill work was undertaken, and is summarised in Chapter 1. The analysis of natural dyes which have been used on museum artefacts other than textiles has received little systematic study, particularly those of non-European origin. In this research, the use of Ultra Performance Liquid Chromatography (UPLC) for study of natural dyes found on historical textiles and ethnographical objects decorated with porcupine quill work is explored; this required a transfer of existing analytical protocols and methodology. The advantages of using Ultra Performance Liquid Chromatography (UPLC) was evaluated through a method development based on the separation and quantification of ten flavonoid and anthraquinone dyes as described in Chapter 2. These methods were then applied to the characterisation of the dye sources found on a group of sixteenth century historical tapestries which form an important part of the Burrell Collection in Glasgow and are believed to have been manufactured in an English workshop (Chapter 3) and also to the analysis of some late nineteenth century North American porcupine quill work from a collection owned by National Museums Scotland (Chapter 5); allowing exciting conclusions to be drawn in each case about the range of dyestuffs used in their manufacture. The second aim of this research was the development of methodology for the non-invasive quantification of metal ion residues on porcupine quill substrates. This was achieved through a comparative study of reference porcupine quills prepared in-house with dyebaths containing a range of metal ion concentrations (copper and tin). The concentration of metal ions sorbed by the porcupine quills was then quantified with Inductively Coupled Plasma (ICP) coupled to Optical Emission Spectrometry (OES) and non-invasive Particle Induced X-Ray Emission analysis (PIXE) coupled with Rutherford Backscattering Spectrometry (RBS) as described in Chapter 4. The responses provided by the different methods were compared and they were then applied to the study of micro-samples collected from mid-nineteenth century Northern Athapaskan porcupine quill work. Unexpectedly, the use of UPLC analysis and RBS-PIXE analysis allowed the characterisation of traded European natural dyes used with metallic mordants (copper and tin) on these samples, highlighting how European contact impacted on traditional Athapaskan porcupine quill work in the late nineteenth century (Chapter 5).
12

Desenvolvimento e validação de métodos analíticos para determinação simultânea de fármacos que atuam no controle da hipertensão arterial / Development and validation of analytical methods for simultaneous determination of drugs that act on the control of hypertension.

Claudia Vilela de Oliveira 13 April 2015 (has links)
A hipertensão arterial é um fator de risco de alta prevalência para as doenças cardiovasculares, principalmente no mundo industrializado, aumentando o problema de saúde em virtude do aumento da longevidade e da prevalência de fatores contribuintes como obesidade, sedentarismo e dietas inadequadas. Estima-se que 10% das 55 milhões de mortes que acontecem a cada ano, são consequências da hipertensão arterial. Dois terços desses eventos ocorrem nos países em desenvolvimento, incluindo o Brasil, afetando principalmente a população de menor nível socioeconômico. Diuréticos como hidroclorotiazida associados a betabloqueadores como o metoprolol são exemplos de fármacos utilizados no controle da hipertensão. O presente trabalho teve como objetivo desenvolver, validar e comparar métodos analíticos para a identificação e quantificação simultânea do tartarato de metoprolol e da hidroclorotiazida por eletroforese capilar (CE) e por cromatografia líquida de ultra eficiência (UHPLC). Para a definição das melhores condições de análise e determinação simultânea dos analitos em estudo, e otimização do método, utilizou-se metodologia de superfície de resposta (ou Response Surface Methodology - RSM). O método por CE utilizou um capilar de sílica fundida com comprimento total de 30,2 cm x 50 &#181;m d.i. O tampão utilizado foi tetraborato de sódio 25,0 mmol L-1, injeção hidrodinâmica 0,5 psi/6s, tensão aplicada +15 kV, detecção em 225 nm temperatura a 25ºC. O tartarato de metoprolol e hidroclorotiazida foram separados em 1,2 e 2,1 min, respectivamente .O método por UHPLC foi realizado empregando uma coluna ZORBAX® SB C18 (50 mm x 2,1 mm x 1,8 &#181;m), fase móvel constituída por água:acetornitrila:trietilamina (83:17:0,2 v/v/v), pH 3 ajustado com ácido fosfórico, utilizou vazão de 0,9 mL min-1. A hidroclorotiazida e o tartarato de metoprolol foram separados em 0,7 e 1,0 min, respectivamente. Os métodos analíticos foram validados de acordo com os requerimentos da ANVISA, ICH e Farmacopéia Americana. Os métodos apresentaram boa linearidade com coeficiente de correlação maiores que 0.99, a precisão intra- e inter-day para os tempos de migração foi apropriada (DPR < 2%), a exatidão do método foi comprovada mediante teste de recuperação, obtendo-se valores de 100±2. Portanto, os métodos propostos demonstraram ser lineares, precisos, exatos e rápidos para quantificação simultânea da hidroclorotiazida e do tartarato de metoprolol. E podem ser considerados confiáveis para serem empregados em análise de rotina para controle de qualidade destes produtos farmacêuticos. / Hypertension is a risk factor of high prevalence for cardiovascular diseases, especially in the industrialized world, increasing health problems as a result of increased longevity and the prevalence of contributing factors such as obesity, physical inactivity and inadequate diets. It is estimated that 10% of 55 million deaths that occur each year, are consequences of hypertension. Two-thirds of those events occur in developing countries, including Brazil, affecting mainly the population from lower socioeconomic backgrounds. Diuretics like hydrochlorothiazide associated with beta-blockers such as metoprolol tartrate are examples of drugs used in the control of hypertension. The present work had as objective to develop, validate and compare analytical methods for identification and simultaneous quantification of metoprolol tartrate and hydrochlorothiazide by capillary electrophoresis (CE) and ultra performance liquid chromatography (UHPLC). For the definition of the best conditions of analysis and simultaneous determination of drugs in study, and optimization of the method, it was used response surface methodology (RSM or \"Response Surface Methodology). The CE method used a fused silica capillary with total length of 30.2 cm x 50 &#181;m d.i. The electrolyte used was sodium tetraborate 25,0 mmol L-1, hydrodynamic injection 0.5 psi/6s, applied voltage +15 kV, detection in 225 nm temperature at 25ºC. The metoprolol tartrate and hydrochlorothiazide were separated into 1.2 and 2.1 min, respectively. The UHPLC method was carried out employing a ZORBAX SB® C18 (50 mm x 2.1 mm x 1.8 &#181;m) column, mobile phase consisting of water: acetornitrila: triethylamine (83: 17: 0.2 v/v/v), 3 pH adjusted with phosphoric acid, the flow was 0.9 mL min-1. Hydrochlorothiazide and metoprolol tartrate were separated in 0.7 and 1.0 min, respectively. The analytical methods have been validated in accordance with the requirements of ANVISA, ICH and American Pharmacopoeia. The methods showed good linearity with correlation coefficient greater than 0.99, precision inter and intra day for times of migration was appropriate (DPR < 2%), the accuracy of the method has been proven by recovery test, obtaining values of 100 ± 2. Therefore, the proposed methods have shown to be linear, precise, accurate and fast for simultaneous quantification of hydrochlorothiazide and metoprolol tartrate; and can be considered reliable to be used in routine analysis for quality control of pharmaceutical products.
13

Aplicação de métodos quimiométricos na investigação do metaboloma de eucalipto por técnicas cromatográficas multidimensionais e hifenadas à espectrometria de massas / Application of chemometric methods to the investigation of the metabolome of eucalyptus by conventional and multidimensional chromatography coupled to mass spectrometry

Hantao, Leandro Wang, 1986- 11 December 2014 (has links)
Orientador: Fabio Augusto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-26T03:33:38Z (GMT). No. of bitstreams: 1 Hantao_LeandroWang_D.pdf: 43243215 bytes, checksum: 64816c43abccdd0dc00de5b11a91371c (MD5) Previous issue date: 2014 / Resumo: O presente trabalho é dedicado à aplicação de técnicas cromatográficas multidimensionais à problemas complexos de separação. No primeiro conjunto de estudos foram desenvolvidos métodos analíticos para investigação do metaboloma de plantas de interesse comercial. Para isso, foram utilizadas a cromatografia gasosa bidimensional abrangente (GC×GC-MS) e a cromatografia líquida de ultra eficiência (UHPLC-MS) acopladas à espectrometria de massas para aquisição do perfil metabólico de folhas de eucalipto. Logo, foram desenvolvidos modelos quimiométricos para interpretação dos dados e determinação de marcadores biológicos associados ao estresse biótico e ao fenômeno de resistência. Estes estudos permitiram aprimorar o entendimento do mecanismo de defesa de eucaliptos contra fitopatógenos. Em segundo plano, foram desenvolvidas fases estacionárias derivadas de líquidos iônicos (IL) para separação de compostos apolares por GC×GC. Para isso, foram sintetizados diversos IL derivados de fosfônio e imidazólio. A partir destes materiais foram preparadas colunas capilares pelo método estático de revestimento. Estas colunas de GC foram utilizadas na separação de analitos modelo (i.e., hidrocarbonetos alifáticos) por GC×GC. Estes ensaios visaram aprimorar o entendimento da relação entre as características estruturais dos IL e os mecanismos que governam a retenção de compostos apolares pelas fases derivadas de IL / Abstract: In the present dissertation, we discuss the application of multidimensional chromatographic techniques to solve complex problems. In the first chapter it is presented the development of chemometric strategies for data processing of metabolic data ¿ the current bottleneck of a metabolomics workflow. The case studies examined investigate the metabolome of eucalyptus leaves to address several growing concern in plant pathology, namely, prospection of orthogonal methods for early diagnosis diseases and selection of hybrids with specific phenotypes in genetic enhancement programs. To accomplish these goals, comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS) and ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) were examined to generate unbiased and reliable metabolic profiles. From these experiments, it was possible to improve our understanding of the defense mechanism of plants. The second chapter addresses the limited availability of stationary phases for multidimensional gas chromatography. In this work, we evaluated ionic liquids as stationary phases for gas-liquid chromatography. The model analytes were nonpolar aliphatic hydrocarbons due to the aggravated lack of highly selective and thermally stable GC columns for their separation. From these experiments, we ascertained the structure-selectivity relationship of ILs and were able to improve our understanding on the retention of nonpolar analytes by IL-based GC columns / Doutorado / Quimica Analitica / Doutor em Ciências
14

Desenvolvimento, validação e aplicação de metodologia para determinação de edulcorantes por HPLC / Development, validation and application of methodology for determination of sweeteners by HPLC

Pane, Daniela de Queiroz, 1977- 19 August 2018 (has links)
Orientador: Helena Teixeira Godoy / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T15:35:59Z (GMT). No. of bitstreams: 1 Pane_DanieladeQueiroz_D.pdf: 2989651 bytes, checksum: 1f92009c2aa35df54d0c45737049c170 (MD5) Previous issue date: 2012 / Resumo: Foi desenvolvido um novo método, eficiente e econômico, para a análise simultânea de cinco edulcorantes em alimentos (acessulfame-k, sacarina, ciclamato, aspartame e neotame) pela técnica de cromatografia líquida de alta eficiência (HPLC). O método foi validado e aplicado em diferentes produtos da categoria &quot;light¿, &quot;diet¿ e &quot;zero¿, sendo esses refrigerantes, néctares, pós para preparo de refresco, pudins, cappuccinos, achocolatados, geléias, gelatina, molho tipo &quot;barbecue¿, catchup e adoçantes de mesa. Para tanto, utilizou-se uma coluna C18, fase móvel composta por fase aquosa (5 mM de tampão fosfato de sódio monobásico; pH 7) e fase orgânica (acetonitrila), eluição por gradiente, vazão de 0,4 mL.min-1 e temperatura de 56ºC. Os edulcorante apresentaram adequada linearidade na faixa de trabalho. A repetitividade, a precisão intermediária e os limites de detecção e de quantificação foram adequados para os cinco edulcorantes. As taxas de recuperação variaram entre 85,2% e 101,4%, para as diferentes matrizes avaliadas. O método apresentou uma limitação para as amostras contendo cacau, onde não foi possível determinar o ciclamato em virtude da presença de um interferente. Até três edulcorantes utilizados em combinação foram encontrados nas amostras, sendo acessulfame-k e aspartame os mais comumente empregados. As amostras de pudim sabor chocolate, molho tipo &quot;catchup¿ e molho tipo &quot;barbecue¿ apresentaram concentrações de edulcorantes acima do permitido pela legislação brasileira. As amostras de refrigerante sabor limão, sabor guaraná, tipo cola e de refresco em pó, embora estivessem atendendo a legislação, apresentaram teor de edulcorantes acima do declarado no rótulo. O método desenvolvido por HPLC foi comparado a uma metodologia por cromatografia líquida de ultra eficiência (UPLC) e apresentou maior robustez e menor custo em comparação ao desenvolvimento para UPLC. Já o método por UPLC demonstrou baixo consumo de solventes, tempo curto de análise, menores limites de detecção e de quantificação, no entanto, maior custo devido ao preparo das amostras e à coluna, solventes, reagentes e filtros envolvidos nas análises / Abstract: We developed a new method, efficient and economical, for the simultaneous analysis of five sweeteners in foods (acesulfame K, saccharin, cyclamate, aspartame and neotame) technique for high performance liquid chromatography (HPLC). The method was validated and applied to different products in the "light", "diet" and "zero", and these soft drinks, nectars, powders for preparation of soft drinks, puddings, cappuccino, chocolate, jams, jelly, sauce type "barbecue" , ketchup and tabletop sweeteners. To both, we used a C18 column, mobile phase consisting of aqueous phase (5 mM sodium phosphate buffer monobasic; pH 7) and organic phase (acetonitrile), gradient elution, flow of 0.4 mL.min-1 and temperature of 56 º C. The sweetener showed acceptable linearity in the range of work. The repeatability, intermediate precision and limits of detection and quantification were adequate for the five sweeteners. Recovery rates ranged between 85.2% and 101.4% for the different matrices evaluated. The method has a limitation for samples containing cocoa, which was not possible to determine cyclamate because of the presence of an interferer. Up to three sweeteners used in combination were found in the samples, with aspartame and acesulfame-k the most commonly employed.Samples of chocolate pudding flavored sauce like "ketchup" sauce like "barbecue" sweeteners showed concentrations above those permitted by Brazilian law. Samples of lemon-flavored soda, flavored guarana, cola and powdered drink mixes, although they were given the rules presented above sweeteners content declared on the label. The method developed HPLC method was compared to an ultra performance liquid chromatographic efficiency (UPLC) and showed greater robustness and lower cost compared to developing for UPLC. Have the method by UPLC demonstrated low consumption of solvents, short time of analysis, lower limits of detection and quantification, however, higher cost due to preparation of samples and the column, solvents, reagents and filters involved in the analyzes / Doutorado / Ciência de Alimentos / Doutor em Ciência de Alimentos
15

Method Development for the Analysis of Smokeless Powders and Organic Gunshot Residue by Ultra Performance Liquid Chromatography with Tandem Mass Spectrometry

Thomas, Jennifer L. 12 November 2013 (has links)
The goal of this project was to develop a rapid separation and detection method for analyzing organic compounds in smokeless powders and then test its applicability on gunshot residue (GSR) samples. In this project, a total of 20 common smokeless powder additives and their decomposition products were separated by ultra performance liquid chromatography (UPLC) and confirmed by tandem mass spectrometry (MS/MS) using multiple reaction monitoring mode (MRM). Some of the targeted compounds included diphenylamines, centralites, nitrotoluenes, nitroglycerin, and various phthalates. The compounds were ionized in the MS source using simultaneous positive and negative electrospray ionization (ESI) with negative atmospheric pressure chemical ionization (APCI) in order to detect all compounds in a single analysis. The developed UPLC/MS/MS method was applied to commercially available smokeless powders and gunshot residue samples recovered from the hands of shooters, spent cartridges, and smokeless powder retrieved from unfired cartridges. Distinct compositions were identified for smokeless powders from different manufacturers and from separate manufacturing lots. The procedure also produced specific chemical profiles when tested on gunshot residues from different manufacturers. Overall, this thesis represents the development of a rapid and reproducible procedure capable of simultaneously detecting the widest possible range of components present in organic gunshot residue.
16

Desenvolvimento de um método indicativo de estabilidade para ondansetrona / Development of a stability indicating method for ondansetron

Maranho, Rafael Finocchiaro 17 October 2017 (has links)
ultravioleta e espectrometria de massas para análise do teor e limite de impurezas e compostos de degradação para o principio ativo farmacêutico ondansetrona e três diferentes formas farmacêuticas foi desenvolvido utilizando conceitos de qualidade analítica por planejamento (aQbD) e validado de acordo com os requerimentos da USP-NF e do ICH. O método desenvolvido apresentou capacidade de separação de vinte compostos detectados nas amostras envolvidas no estudo: o princípio ativo ondansetrona, sete impurezas descritas nos principais compêndios farmacopéicos mundiais (United States Pharmacopeia-National Formulary, European Pharmacopoeia, British Pharmacopoeia e Indian Pharmacopoeia), onze compostos de degradação gerados pelos estudos de estresse e um excipiente. O método final apresentou um tempo de corrida de 14 minutos, com vazão de fase móvel de 0,4 mL/min, detecção de impurezas por ultravioleta a 220 nm e do princípio ativo a 305 nm, com apoio da detecção por espectrometria de massas de alta resolução (QTOF). Em comparação aos métodos requeridos pelas monografias relacionadas à ondansetrona publicadas nos compêndios farmacopéicos citados, o método desenvolvido apresenta uma alternativa eficiente e econômica para a análise de rotina de diferentes formas da matéria-prima ondansetrona (base, cloridrato, diferentes níveis de hidratação) e formas farmacêuticas (comprimidos, comprimidos de desintegração oral e solução injetável), mostrando que a modernização dos métodos cromatográficos, além de garantir a qualidade dos produtos farmacêuticos e promover a saúde da população, tem um impacto relevante na economia da produção e análise de medicamentos e na diminuição do impacto ao meio ambiente / An analytical method by ultraperformance liquid chromatography and detection by UV and mass spectrometry for assay and limit test for impurities and degradation compounds for the active pharmaceutical ingredient ondansetron and three different pharmaceutical products was developed using the analytical Quality by Design (aQbD) approach, and was validated according to the USP-NF and ICH requirements. The analytical method was efficient for the separation of twenty different compounds, detected in the samples involved in this study: the active ingredient ondansetron, seven impurities mentioned in the main global pharmacopeial compendia (United States Pharmacopeia-National Formulary, European Pharmacopoeia, British Pharmacopoeia e Indian Pharmacopoeia), eleven degradation compounds detected in the samples from stress studies and one excipient. The final method was composed by a 14 minutes run, using mobile phase flow at 0.4 mL/min, detection by UV at 220 nm for the impurities and degradation compounds and at 305 nm for ondansetron, supported by the high-resolution mass spectrometry detection (QTOF). Comparing the method developed with the chromatographic methods required by the monographs related to ondansetron published in the mentioned pharmacopeial compendia, it represents an efficient and economic alternative to the routine analysis of different ondansetron raw material forms (base, hydrochloride, different hydrates) and pharmaceutical products (tablets, orally disintegrating tablets and injectable), demonstrating the importance of the modernization of analytical procedures, with regard to not only the quality assurance of pharmaceutical products and promotion of public health, but also to the positive impact on the economy and sustainability of the pharmaceutical analysis and manufacturing.
17

Desenvolvimento de uma fase extratora com polímeros de impressão molecular para extração em fase sólida de Venlafaxina, O-desmetilvenlafaxina e N-desmetilvenlafaxina em amostras de plasmas e análises por cromatografia líquida de ultra eficiência acoplada à espectometria de massas em tandem (UPLC-MS/MS). / Development of an extraction phase with molecularly imprinted polymers for solid phase extraction of venlafaxine, o-desmethylvenlafaxine, and n-desmethylvenlafaxine in plasma samples and analysis by Ultra Performance Liquid Chromatography-tandem mass spectrometry (UPLC-MS/MS)

Miranda, Luís Felippe Cabral 18 March 2015 (has links)
A venlafaxina (VEN), em razão de sua eficácia e brandos efeitos adversos, tem sido um dos antidepressivos mais prescritos no tratamento da depressão e ansiedade. Neste trabalho, um método analítico empregando as técnicas MISPE miniaturizada e cromatografia líquida acoplada à espectrometria de massas em Tandem, foi utilizado para a determinação de VEN e seus principais metabólitos em amostras de plasma para fins de monitorização terapêutica. A fase MIP foi sintetizada via polimerização radicalar por precipitação, fazendo uso de VEN (molécula molde), ácido metacrílico (monômero funcional), etileno glicol dimetacrilato, (reagente reticulante) e 2,2 azobisisobutironitrila (iniciador radicalar) em tolueno (solvente). Para controle utilizou-se o polímero não impresso (NIP), sintetizado por procedimento análogo ao do MIP, porém sem o uso da molécula molde. A caracterização química e estrutural dos polímeros foi realizada por espectroscopia no infravermelho com transformada de fourier e microscopia eletrônica de varredura. A otimização das variáveis de MISPE miniaturizada favoreceu a detectabilidade analítica e diminuiu o efeito de memória. As extrações realizadas com MIP apresentaram taxa de recuperação de 84% para VEN e de 2-28% para os antidepressivos (clorpromazina, fluoxetina, clomipramina, imipramina e sertralina). O polímero não impresso apresentou baixa recuperação para a VEN (taxa de recuperação: 49%) e para os demais antidepressivos (taxas de recuperação menores que 40%). Estes experimentos comprovam a seletividade da fase MIP desenvolvida. O método padronizado apresentou linearidade na faixa de 3 a 700 ng mL-1 para VEN, 5 a 700 ng mL-1 para O-desmetilvenlafaxina (ODV) e de 3 a 500 ng mL-1 para N-desmetilvenlafaxina (NDV), precisão com coeficientes de variação menores que 15% e exatidão com valores de erro padrão relativo na faixa de -11,8 a 16,01 %. As concentrações correspondentes aos limites inferiores de quantificação para VEN (3 ng mL-1) e ODV ( 5 ng mL-1) foram inferiores aos intervalos terapêuticos preconizados. O método desenvolvido, quando comparado a aos métodos da literatura para determinação de VEN e metabolitos, apresentou maior seletividade, menor consumo de amostra e de solventes orgânicos e permitiu a reutilização da fase extratora. Segundo os parâmetros de validação analítica avaliados e amostras de pacientes em terapia com VEN analisadas, o método proposto é adequado para determinação de VEN, ODV e NDV em amostras de plasma para fins de monitorização terapêutica. / Venlafaxine elicits a small number of adverse effects, so it is one of the most frequently prescribed drugs to treat major depression, generalized anxiety, and social anxiety disorders in adults. In this study, venlafaxine (VEN), O-desmethylvenlafaxine (ODV), and N-desmethylvenlafaxine (NDV) were pre-concentrated with the aid of miniaturized SPE based on MIPs as extraction phase. MIPs are synthetic polymers with cavities specifically designed to hold a target molecule or structurally similar compounds. The molecularly imprinted polymers were prepared by addition of VEN, metacrylic acid (MAA, monomer), ethylene glycol dimethacrylate (EGDMA, cross-linker), and 2,2-azobisisobutyronitrile (AIBN, initiator) to toluene (solvent). The non-imprinted polymer (NIP), used for comparison, was also synthesized by following exactly the same procedure, but excluding the template VEN from the formulation. The polymer was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). Optimization of the MIP phase extraction variables favored miniaturized analytical detectability and reduced the memory effect. The extractions performed with the synthesized MIP showed recovery rate of 84% for VEN and 2-28% for other antidepressants (chlorpromazine, fluoxetine, clomipramine, imipramine, and sertraline). The non-imprinted polymer provided low recovery of VEN (recovery rate: 49%) and other antidepressants (recovery rates lower than 40%). These experiments demonstrated the selectivity of the developed MIP phase. The standardized method was linear in the range of 300 - 700 ng mL-1 for VEN, 5-700 ng mL-1 for ODV, and 3 to 500 ng mL-1 for NDV. Precision had coefficients of variation smaller than 15%; the accuracy standard error values ranged from -11.8 to 16.01%. Compared with literature methods, the developed method was more selective for determination of VEN and metabolites, required lower consumption of sample and organic solvents, and enabled reuse of the extraction phase. According to the assessed analytical validation parameters and to the analysis of samples obtained from patients undergoing therapy with VEN, the proposed method is suitable to determine VEN, NDV, and ODV in plasma samples for therapeutic drug monitoring.
18

Desenvolvimento de um método indicativo de estabilidade para ondansetrona / Development of a stability indicating method for ondansetron

Rafael Finocchiaro Maranho 17 October 2017 (has links)
ultravioleta e espectrometria de massas para análise do teor e limite de impurezas e compostos de degradação para o principio ativo farmacêutico ondansetrona e três diferentes formas farmacêuticas foi desenvolvido utilizando conceitos de qualidade analítica por planejamento (aQbD) e validado de acordo com os requerimentos da USP-NF e do ICH. O método desenvolvido apresentou capacidade de separação de vinte compostos detectados nas amostras envolvidas no estudo: o princípio ativo ondansetrona, sete impurezas descritas nos principais compêndios farmacopéicos mundiais (United States Pharmacopeia-National Formulary, European Pharmacopoeia, British Pharmacopoeia e Indian Pharmacopoeia), onze compostos de degradação gerados pelos estudos de estresse e um excipiente. O método final apresentou um tempo de corrida de 14 minutos, com vazão de fase móvel de 0,4 mL/min, detecção de impurezas por ultravioleta a 220 nm e do princípio ativo a 305 nm, com apoio da detecção por espectrometria de massas de alta resolução (QTOF). Em comparação aos métodos requeridos pelas monografias relacionadas à ondansetrona publicadas nos compêndios farmacopéicos citados, o método desenvolvido apresenta uma alternativa eficiente e econômica para a análise de rotina de diferentes formas da matéria-prima ondansetrona (base, cloridrato, diferentes níveis de hidratação) e formas farmacêuticas (comprimidos, comprimidos de desintegração oral e solução injetável), mostrando que a modernização dos métodos cromatográficos, além de garantir a qualidade dos produtos farmacêuticos e promover a saúde da população, tem um impacto relevante na economia da produção e análise de medicamentos e na diminuição do impacto ao meio ambiente / An analytical method by ultraperformance liquid chromatography and detection by UV and mass spectrometry for assay and limit test for impurities and degradation compounds for the active pharmaceutical ingredient ondansetron and three different pharmaceutical products was developed using the analytical Quality by Design (aQbD) approach, and was validated according to the USP-NF and ICH requirements. The analytical method was efficient for the separation of twenty different compounds, detected in the samples involved in this study: the active ingredient ondansetron, seven impurities mentioned in the main global pharmacopeial compendia (United States Pharmacopeia-National Formulary, European Pharmacopoeia, British Pharmacopoeia e Indian Pharmacopoeia), eleven degradation compounds detected in the samples from stress studies and one excipient. The final method was composed by a 14 minutes run, using mobile phase flow at 0.4 mL/min, detection by UV at 220 nm for the impurities and degradation compounds and at 305 nm for ondansetron, supported by the high-resolution mass spectrometry detection (QTOF). Comparing the method developed with the chromatographic methods required by the monographs related to ondansetron published in the mentioned pharmacopeial compendia, it represents an efficient and economic alternative to the routine analysis of different ondansetron raw material forms (base, hydrochloride, different hydrates) and pharmaceutical products (tablets, orally disintegrating tablets and injectable), demonstrating the importance of the modernization of analytical procedures, with regard to not only the quality assurance of pharmaceutical products and promotion of public health, but also to the positive impact on the economy and sustainability of the pharmaceutical analysis and manufacturing.
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Desenvolvimento de uma fase extratora com polímeros de impressão molecular para extração em fase sólida de Venlafaxina, O-desmetilvenlafaxina e N-desmetilvenlafaxina em amostras de plasmas e análises por cromatografia líquida de ultra eficiência acoplada à espectometria de massas em tandem (UPLC-MS/MS). / Development of an extraction phase with molecularly imprinted polymers for solid phase extraction of venlafaxine, o-desmethylvenlafaxine, and n-desmethylvenlafaxine in plasma samples and analysis by Ultra Performance Liquid Chromatography-tandem mass spectrometry (UPLC-MS/MS)

Luís Felippe Cabral Miranda 18 March 2015 (has links)
A venlafaxina (VEN), em razão de sua eficácia e brandos efeitos adversos, tem sido um dos antidepressivos mais prescritos no tratamento da depressão e ansiedade. Neste trabalho, um método analítico empregando as técnicas MISPE miniaturizada e cromatografia líquida acoplada à espectrometria de massas em Tandem, foi utilizado para a determinação de VEN e seus principais metabólitos em amostras de plasma para fins de monitorização terapêutica. A fase MIP foi sintetizada via polimerização radicalar por precipitação, fazendo uso de VEN (molécula molde), ácido metacrílico (monômero funcional), etileno glicol dimetacrilato, (reagente reticulante) e 2,2 azobisisobutironitrila (iniciador radicalar) em tolueno (solvente). Para controle utilizou-se o polímero não impresso (NIP), sintetizado por procedimento análogo ao do MIP, porém sem o uso da molécula molde. A caracterização química e estrutural dos polímeros foi realizada por espectroscopia no infravermelho com transformada de fourier e microscopia eletrônica de varredura. A otimização das variáveis de MISPE miniaturizada favoreceu a detectabilidade analítica e diminuiu o efeito de memória. As extrações realizadas com MIP apresentaram taxa de recuperação de 84% para VEN e de 2-28% para os antidepressivos (clorpromazina, fluoxetina, clomipramina, imipramina e sertralina). O polímero não impresso apresentou baixa recuperação para a VEN (taxa de recuperação: 49%) e para os demais antidepressivos (taxas de recuperação menores que 40%). Estes experimentos comprovam a seletividade da fase MIP desenvolvida. O método padronizado apresentou linearidade na faixa de 3 a 700 ng mL-1 para VEN, 5 a 700 ng mL-1 para O-desmetilvenlafaxina (ODV) e de 3 a 500 ng mL-1 para N-desmetilvenlafaxina (NDV), precisão com coeficientes de variação menores que 15% e exatidão com valores de erro padrão relativo na faixa de -11,8 a 16,01 %. As concentrações correspondentes aos limites inferiores de quantificação para VEN (3 ng mL-1) e ODV ( 5 ng mL-1) foram inferiores aos intervalos terapêuticos preconizados. O método desenvolvido, quando comparado a aos métodos da literatura para determinação de VEN e metabolitos, apresentou maior seletividade, menor consumo de amostra e de solventes orgânicos e permitiu a reutilização da fase extratora. Segundo os parâmetros de validação analítica avaliados e amostras de pacientes em terapia com VEN analisadas, o método proposto é adequado para determinação de VEN, ODV e NDV em amostras de plasma para fins de monitorização terapêutica. / Venlafaxine elicits a small number of adverse effects, so it is one of the most frequently prescribed drugs to treat major depression, generalized anxiety, and social anxiety disorders in adults. In this study, venlafaxine (VEN), O-desmethylvenlafaxine (ODV), and N-desmethylvenlafaxine (NDV) were pre-concentrated with the aid of miniaturized SPE based on MIPs as extraction phase. MIPs are synthetic polymers with cavities specifically designed to hold a target molecule or structurally similar compounds. The molecularly imprinted polymers were prepared by addition of VEN, metacrylic acid (MAA, monomer), ethylene glycol dimethacrylate (EGDMA, cross-linker), and 2,2-azobisisobutyronitrile (AIBN, initiator) to toluene (solvent). The non-imprinted polymer (NIP), used for comparison, was also synthesized by following exactly the same procedure, but excluding the template VEN from the formulation. The polymer was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). Optimization of the MIP phase extraction variables favored miniaturized analytical detectability and reduced the memory effect. The extractions performed with the synthesized MIP showed recovery rate of 84% for VEN and 2-28% for other antidepressants (chlorpromazine, fluoxetine, clomipramine, imipramine, and sertraline). The non-imprinted polymer provided low recovery of VEN (recovery rate: 49%) and other antidepressants (recovery rates lower than 40%). These experiments demonstrated the selectivity of the developed MIP phase. The standardized method was linear in the range of 300 - 700 ng mL-1 for VEN, 5-700 ng mL-1 for ODV, and 3 to 500 ng mL-1 for NDV. Precision had coefficients of variation smaller than 15%; the accuracy standard error values ranged from -11.8 to 16.01%. Compared with literature methods, the developed method was more selective for determination of VEN and metabolites, required lower consumption of sample and organic solvents, and enabled reuse of the extraction phase. According to the assessed analytical validation parameters and to the analysis of samples obtained from patients undergoing therapy with VEN, the proposed method is suitable to determine VEN, NDV, and ODV in plasma samples for therapeutic drug monitoring.
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Applications and challenges in mass spectrometry-based untargeted metabolomics

Jones, Christina Michele 27 May 2016 (has links)
Metabolomics is the methodical scientific study of biochemical processes associated with the metabolome—which comprises the entire collection of metabolites in any biological entity. Metabolome changes occur as a result of modifications in the genome and proteome, and are, therefore, directly related to cellular phenotype. Thus, metabolomic analysis is capable of providing a snapshot of cellular physiology. Untargeted metabolomics is an impartial, all-inclusive approach for detecting as many metabolites as possible without a priori knowledge of their identity. Hence, it is a valuable exploratory tool capable of providing extensive chemical information for discovery and hypothesis-generation regarding biochemical processes. A history of metabolomics and advances in the field corresponding to improved analytical technologies are described in Chapter 1 of this dissertation. Additionally, Chapter 1 introduces the analytical workflows involved in untargeted metabolomics research to provide a foundation for Chapters 2 – 5. Part I of this dissertation which encompasses Chapters 2 – 3 describes the utilization of mass spectrometry (MS)-based untargeted metabolomic analysis to acquire new insight into cancer detection. There is a knowledge deficit regarding the biochemical processes of the origin and proliferative molecular mechanisms of many types of cancer which has also led to a shortage of sensitive and specific biomarkers. Chapter 2 describes the development of an in vitro diagnostic multivariate index assay (IVDMIA) for prostate cancer (PCa) prediction based on ultra performance liquid chromatography-mass spectrometry (UPLC-MS) metabolic profiling of blood serum samples from 64 PCa patients and 50 healthy individuals. A panel of 40 metabolic spectral features was found to be differential with 92.1% sensitivity, 94.3% specificity, and 93.0% accuracy. The performance of the IVDMIA was higher than the prevalent prostate-specific antigen blood test, thus, highlighting that a combination of multiple discriminant features yields higher predictive power for PCa detection than the univariate analysis of a single marker. Chapter 3 describes two approaches that were taken to investigate metabolic patterns for early detection of ovarian cancer (OC). First, Dicer-Pten double knockout (DKO) mice that phenocopy many of the features of metastatic high-grade serous carcinoma (HGSC) observed in women were studied. Using UPLC-MS, serum samples from 14 early-stage tumor DKO mice and 11 controls were analyzed. Iterative multivariate classification selected 18 metabolites that, when considered as a panel, yielded 100% accuracy, sensitivity, and specificity for early-stage HGSC detection. In the second approach, serum metabolic phenotypes of an early-stage OC pilot patient cohort were characterized. Serum samples were collected from 24 early-stage OC patients and 40 healthy women, and subsequently analyzed using UPLC-MS. Multivariate statistical analysis employing support vector machine learning methods and recursive feature elimination selected a panel of metabolites that differentiated between age-matched samples with 100% cross-validated accuracy, sensitivity, and specificity. This small pilot study demonstrated that metabolic phenotypes may be useful for detecting early-stage OC and, thus, supports conducting larger, more comprehensive studies. Many challenges exist in the field of untargeted metabolomics. Part II of this dissertation which encompasses Chapters 4 – 5 focuses on two specific challenges. While metabolomic data may be used to generate hypothesis concerning biological processes, determining causal relationships within metabolic networks with only metabolomic data is impractical. Proteins play major roles in these networks; therefore, pairing metabolomic information with that acquired from proteomics gives a more comprehensive snapshot of perturbations to metabolic pathways. Chapter 4 describes the integration of MS- and NMR-based metabolomics with proteomics analyses to investigate the role of chemically mediated ecological interactions between Karenia brevis and two diatom competitors, Asterionellopsis glacialis and Thalassiosira pseudonana. This integrated systems biology approach showed that K. brevis allelopathy distinctively perturbed the metabolisms of these two competitors. A. glacialis had a more robust metabolic response to K. brevis allelopathy which may be a result of its repeated exposure to K. brevis blooms in the Gulf of Mexico. However, K. brevis allelopathy disrupted energy metabolism and obstructed cellular protection mechanisms including altering cell membrane components, inhibiting osmoregulation, and increasing oxidative stress in T. pseudonana. This work represents the first instance of metabolites and proteins measured simultaneously to understand the effects of allelopathy or in fact any form of competition. Chromatography is traditionally coupled to MS for untargeted metabolomics studies. While coupling chromatography to MS greatly enhances metabolome analysis due to the orthogonality of the techniques, the lengthy analysis times pose challenges for large metabolomics studies. Consequently, there is still a need for developing higher throughput MS approaches. A rapid metabolic fingerprinting method that utilizes a new transmission mode direct analysis in real time (TM-DART) ambient sampling technique is presented in Chapter 5. The optimization of TM-DART parameters directly affecting metabolite desorption and ionization, such as sample position and ionizing gas desorption temperature, was critical in achieving high sensitivity and detecting a broad mass range of metabolites. In terms of reproducibility, TM-DART compared favorably with traditional probe mode DART analysis, with coefficients of variation as low as 16%. TM-DART MS proved to be a powerful analytical technique for rapid metabolome analysis of human blood sera and was adapted for exhaled breath condensate (EBC) analysis. To determine the feasibility of utilizing TM-DART for metabolomics investigations, TM-DART was interfaced with traveling wave ion mobility spectrometry (TWIMS) time-of-flight (TOF) MS for the analysis of EBC samples from cystic fibrosis patients and healthy controls. TM-DART-TWIMS-TOF MS was able to successfully detect cystic fibrosis in this small sample cohort, thereby, demonstrating it can be employed for probing metabolome changes. Finally, in Chapter 6, a perspective on the presented work is provided along with goals on which future studies may focus.

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