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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of methods for the analysis of human protamine via 2D LC-MS/MS

Samuel, Jacob Matthew 25 October 2018 (has links)
Protamine, a set of small basic proteins (P1 and P2), play a key role in compacting and protecting the DNA in sperm. As such, the structure of how P1 and P2 bind to DNA and potentially themselves and each other is of interest to several fields including forensics. In forensic DNA analysis, protamine binding of DNA is taken advantage of in the “differential extraction” procedure in which a sample that contains sperm and non-sperm cells can have DNA from the two different cell types separated and extracted at different points thus preventing a mixture of DNA. A key component of this greater structure and what makes the differential extraction functional are the disulfide bonds formed by protamine. So as a first step to elucidating the protamine-DNA complex, methods to analyze human protamine via 2D-Liquid Chromatography-Mass Spectrometry (2D-LC-MS) were developed in the hopes they could be used for disulfide bond mapping. Methods and multiple strategies for digestion, 2D-LC-MS were investigated and developed using chum salmon protamine. Digestion strategies were developed for Chymotrypsin and Lys-C, Trypsin or Arg-C with incubation times and substrate:enzyme mass ratios optimized. Various “trap and elute” 2D-chromatography configuration were tested for analysis intact and digested protein. Using H2O with 2% NH4OH as the loading mobile phase and H2O and Acetonitrile both with 0.5% formic acid as the eluting mobile phases with the first dimension column being an HLB (Hydrophilic Lipophilic Balance) 2.1 x 30 mm column and the second dimension being an C18 2.1 x 100 mm was found to produce the highest signal.
2

Cromatografia líquida multidimensional e espectrometria de massas em tandem para análise direta de fármacos em fluidos biológicos: da escala convencional à miniaturizada / Multidimensional liquid chromatography and tandem mass spectrometry for the direct analysis of grugs in biofluids: from the conventional to the miniaturized scale

Santos Neto, Álvaro José dos 31 August 2007 (has links)
A análise de fármacos e outras moléculas relacionadas em fluidos biológicos é essencial no âmbito farmacêutico. Atualmente, a demanda por análises rápidas e mais complexas impulsiona a química analítica para o desenvolvimento de soluções inovadoras. A cromatografia líquida multidimensional com acoplamento de colunas para injeção direta de fluidos biológicos tem ganhado atenção nos últimos anos. Ao mesmo tempo, o acoplamento entre cromatografia líquida e espectrometria de massas proporcionou marcante desenvolvimento científico na área biomédica e bioquímica. Esta tese apresenta os diversos estágios na redução da escala em sistemas de column switching utilizando colunas RAM, para a análise de fármacos em fluidos biológicos. Na escala convencional, com colunas de 4,6 mm de diâmetro interno, desenvolveu-se um sistema para a análise de fluoxetina em plasma. A metodologia desenvolvida foi adequadamente validada para aplicação na monitorização terapêutica, com tempo de análise de 20 minutos (incluído o preparo de amostras) e consumo de apenas 100 µL de amostra. Avaliou-se a escala microbore (2,1 mm), a qual apresentou excelente potencialidade para o acoplamento com a espectrometria de massas utilizando ionização por electrospray. Na primeira etapa em escala capilar, com colunas de 520 µm de diâmetro interno, desenvolveu-se um sistema para análise de fluoxetina em plasma. Esse sistema proporcionou análises em 25 minutos, também aplicáveis à monitorização terapêutica, consumindo poucos microlitros de amostra. Finalmente, foi desenvolvido um sistema de column switching capilar com colunas na ordem de 200 µm. Esse sistema foi acoplado à espectrometria de massas em tandem proporcionando, inovadoramente, análises altamente sensíveis e simultâneas, com baixo consumo de amostras. Um grupo de cinco antidepressivos e o albendazol, com seus produtos de biotransformação, tiveram suas análises validadas em menos de 8 minutos, consumindo menos de um microlitro de amostra. Esse sistema capilar contrasta com os sistemas convencionais comumente utilizados, os quais consomem entre centenas e milhares de vezes mais amostra para atingir a mesma detectabilidade. / Analysis of drugs and other related molecules in biofluids is essential in the pharmaceutical field. Nowadays, the development of innovative solutions in analytical chemistry has been pushed by the needs for speed and more complex analysis. Lately, multidimensional liquid chromatography using column switching for direct injection of biofluids has gained attention. At the same time, liquid chromatography hyphenated with mass spectrometry provided remarkable scientific development in biomedical and biochemical area. This thesis presents the scale reduction steps in RAM column switching, for drug analysis in biofluids. In the conventional scale, using 4.6 mm i.d. columns, a system was developed, providing fluoxetine analysis in plasma. The developed method resulted in a 20 min long run, including the sample preparation step, which consumed 100 µL of sample. The method was adequately validated, being applicable to therapeutic drug monitoring. The microbore scale (2.1 mm) was evaluated, presenting great potentiality for coupling with electrospray-mass spectrometry. In the first capillary scale step, using 520 µm columns, a system was developed for fluoxetine analysis. Fluoxetine analysis was achieved in 25 min, within the application range for therapeutic drug monitoring, and consuming few microliters of sample. Finally, a RAM capillary column switching system employing columns on the order of 200 µm was developed, in an innovative way. This system was coupled with a tandem mass spectrometer, rendering sensitive and simultaneous analysis with reduced sample volume. The analysis of one group containing five antidepressants, as well as the analysis of albendazol and its metabolites was validated. These analyses took only 8 minutes and consumed less than one microliter of sample. In contrast with conventional systems, this system consumes about hundreds or thousands times less sample, with the same detectability.
3

Cromatografia líquida multidimensional e espectrometria de massas em tandem para análise direta de fármacos em fluidos biológicos: da escala convencional à miniaturizada / Multidimensional liquid chromatography and tandem mass spectrometry for the direct analysis of grugs in biofluids: from the conventional to the miniaturized scale

Álvaro José dos Santos Neto 31 August 2007 (has links)
A análise de fármacos e outras moléculas relacionadas em fluidos biológicos é essencial no âmbito farmacêutico. Atualmente, a demanda por análises rápidas e mais complexas impulsiona a química analítica para o desenvolvimento de soluções inovadoras. A cromatografia líquida multidimensional com acoplamento de colunas para injeção direta de fluidos biológicos tem ganhado atenção nos últimos anos. Ao mesmo tempo, o acoplamento entre cromatografia líquida e espectrometria de massas proporcionou marcante desenvolvimento científico na área biomédica e bioquímica. Esta tese apresenta os diversos estágios na redução da escala em sistemas de column switching utilizando colunas RAM, para a análise de fármacos em fluidos biológicos. Na escala convencional, com colunas de 4,6 mm de diâmetro interno, desenvolveu-se um sistema para a análise de fluoxetina em plasma. A metodologia desenvolvida foi adequadamente validada para aplicação na monitorização terapêutica, com tempo de análise de 20 minutos (incluído o preparo de amostras) e consumo de apenas 100 µL de amostra. Avaliou-se a escala microbore (2,1 mm), a qual apresentou excelente potencialidade para o acoplamento com a espectrometria de massas utilizando ionização por electrospray. Na primeira etapa em escala capilar, com colunas de 520 µm de diâmetro interno, desenvolveu-se um sistema para análise de fluoxetina em plasma. Esse sistema proporcionou análises em 25 minutos, também aplicáveis à monitorização terapêutica, consumindo poucos microlitros de amostra. Finalmente, foi desenvolvido um sistema de column switching capilar com colunas na ordem de 200 µm. Esse sistema foi acoplado à espectrometria de massas em tandem proporcionando, inovadoramente, análises altamente sensíveis e simultâneas, com baixo consumo de amostras. Um grupo de cinco antidepressivos e o albendazol, com seus produtos de biotransformação, tiveram suas análises validadas em menos de 8 minutos, consumindo menos de um microlitro de amostra. Esse sistema capilar contrasta com os sistemas convencionais comumente utilizados, os quais consomem entre centenas e milhares de vezes mais amostra para atingir a mesma detectabilidade. / Analysis of drugs and other related molecules in biofluids is essential in the pharmaceutical field. Nowadays, the development of innovative solutions in analytical chemistry has been pushed by the needs for speed and more complex analysis. Lately, multidimensional liquid chromatography using column switching for direct injection of biofluids has gained attention. At the same time, liquid chromatography hyphenated with mass spectrometry provided remarkable scientific development in biomedical and biochemical area. This thesis presents the scale reduction steps in RAM column switching, for drug analysis in biofluids. In the conventional scale, using 4.6 mm i.d. columns, a system was developed, providing fluoxetine analysis in plasma. The developed method resulted in a 20 min long run, including the sample preparation step, which consumed 100 µL of sample. The method was adequately validated, being applicable to therapeutic drug monitoring. The microbore scale (2.1 mm) was evaluated, presenting great potentiality for coupling with electrospray-mass spectrometry. In the first capillary scale step, using 520 µm columns, a system was developed for fluoxetine analysis. Fluoxetine analysis was achieved in 25 min, within the application range for therapeutic drug monitoring, and consuming few microliters of sample. Finally, a RAM capillary column switching system employing columns on the order of 200 µm was developed, in an innovative way. This system was coupled with a tandem mass spectrometer, rendering sensitive and simultaneous analysis with reduced sample volume. The analysis of one group containing five antidepressants, as well as the analysis of albendazol and its metabolites was validated. These analyses took only 8 minutes and consumed less than one microliter of sample. In contrast with conventional systems, this system consumes about hundreds or thousands times less sample, with the same detectability.

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