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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.
31

SIMPLE AND RAPID ASSAY METHOD FOR SIMULTANEOUS QUANTIFICATION OF URINARY NICOTINE AND COTININE USING MICRO-EXTRACTION BY PACKED SORBENT AND GAS CHROMATOGRAPHY-MASS SPECTROMETRY

Seno, Hiroshi, Suzuki, Osamu, Ishii, Akira, Zaitsu, Kei, Hattori, Hideki, Ogawa, Tadashi, Iwai, Masae 08 1900 (has links)
No description available.
32

Development and analytical validation of a gas chromatography-mass spectrometry method for the assessment of gastrointestinal permeability and intestinal absorptive capacity in dogs

Rodriguez Frausto, Heriberto 15 May 2009 (has links)
Assessment of gastrointestinal permeability in vivo is considered a suitable method for the evaluation of gastrointestinal mucosal integrity. Probes commonly used include lactulose (L) and rhamnose (R) for the assessment of intestinal permeability, xylose (X) and 3-O-methylglucose (M) for the evaluation of intestinal absorptive capacity, and sucrose (S) for the assessment of gastric permeability. Traditionally, various methods have been used to quantify these markers in the urine after orogastric administration. However, urine collection is difficult and uncomfortable. A protocol based on the analysis of blood samples would be easier to perform. Thus, the aim of the first part of this project was to develop and validate a new gas chromatography-mass spectrometry (GC-MS) method for the quantification of five sugar probes in canine serum. The method was sensitive, accurate, precise, and reproducible for the simultaneous quantification of 5 sugar probes in serum. The aim of the second part of this project was to assess the kinetic profiles of these 5 sugar probes in serum after orogastric administration in dogs and to determine the optimal time point for sample collection. Dogs received a solution containing L (10 g/L), R (10 g/L), X (10 g/L), M (5 g/L), and S (40 g/L) by orogastric intubation. Baseline blood samples were collected. Subsequent timed blood samples were taken for a 24 hours period. Significant changes in serum concentrations of all 5 sugars were detected after administration of the test dose (p<0.0001 for all 5 probes). Serum concentrations of L and R were significantly different from baseline concentrations from 90 to 240 and from 60 to 300 min post dosing respectively, and those of X, M, and S were significantly different from 30 to 240 min after dosing (p<0.05 for all 5 probes). Variations of the mean sugar concentrations of all dogs at 90, 120, and 180 minutes were analyzed using a Kruskal-Wallis test. Based on the results, only two blood samples, one taken at baseline and a second sample obtained between 90 and 180 after dosing, appear to be sufficient for assessment of intestinal permeability and mucosal absorptive capacity using these sugar probes.
33

Prospecting for markers of disease in respiratory diseases

Guallar-Hoyas, Cristina January 2013 (has links)
Asthma, current detection methods and metabolites proposed as asthma markers are described. The limitation of the disease diagnosis is outlined and metabolomics is introduced as the approach carried out within this research with the potential to measure the group metabolites that characterise the metabolic responses of a biological system to a specific disease. Chemistry underlying breathing, current breath collection and analytical techniques are described as well as detection and data processing technology associated within our research. A work-flow for the collection, analysis and processing of exhaled breath samples in respiratory diseases is described. The non-invasive sampling method allows collection of exhaled breath samples on children and adults without experiencing any discomfort. The analysis of exhaled breath samples using thermal desorption gas chromatography mass spectrometry outlines the use of retention index for the alignment of VOCs retention time shifting over time. This methodology enables the creation of a breath matrix for multivariate analysis data processing where each VOC is defined by retention index and most intense fragments of the mass spectrum. This methodology is tested in two cohorts of participants: paediatric asthma and severe asthmatic participants whose breath profiles are compared against healthy controls and within the two asthmatic phenotypes to prospect the markers that differentiate between the different groups. Eight candidate markers are identified to discriminate between asthmatic children and healthy children and seven markers between asthmatics undergoing therapy and healthy controls. The database from severe and paediatric asthma is compared, establishing seven non-age related markers between the two groups. A new interface is developed for the faster analysis of exhaled breath samples using thermal desorption ion mobility mass spectrometry. The interface front end has been modified and optimised to achieve the best sensitivity and resolution of VOCs in exhaled breath. A preliminary study carried out in a small cohort of volunteers shows the feasibility of the technique for the differentiation of asthmatic and healthy adults.
34

Advances in cone penetrometry and fast gas chromatography-mass spectrometry for the sampling and analysis of subsurface pollutants /

Smárason, Sigurður Vidir. January 2000 (has links)
Thesis (Ph.D.)--Tufts University, 2000. / Submitted to the Dept. of Chemistry. Adviser: Albert Robbat, Jr. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;
35

Liquid chromatography-mass spectrometry study of two biochemical alcohol markers /

Stephanson, Niclas Nikolai, January 2007 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.
36

Spectroscopic data and multivariate analysis : tools to study genetic perturbations in poplar trees /

Wiklund, Susanne, January 2007 (has links)
Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 5 uppsatser.
37

Quantitative analysis of catecholamines and their metabolites in human urine by gas chromatography - mass spectrometry as a screening method for sympatho - adrenal tumors

Marais, Brian January 2008 (has links)
Thesis (MSc.(Chemical Pathology)--Faculty of Health Sciences)-University of Pretoria, 2008. / Summary in English and Afrikaans. Includes bibliographical references.
38

Determination of pharmaceuticals and personal care products in fish using high performance liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry

Ramirez, Alejandro Javier. Chambliss, C. Kevin. Brooks, Bryan William, January 2007 (has links)
Thesis (Ph.D)--Baylor University, 2007. / Includes bibliographical references (p. 137-142).
39

Characterization of laboratory simulated road paving-like asphalt by high performance liquid chromatography and gas chromatography-mass spectrometry

Law, Brandon F. January 2006 (has links)
Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vii, 60 p. : ill. Includes abstract. Includes bibliographical references.
40

Primary fatty acid amides in mammalian tissues isolation and analysis by HPTLC and SPE in conjunction with GC/MS /

Sultana, Tamanna. January 2005 (has links)
Thesis (Ph.D.)--Duquesne University, 2005. / Title from document title page. Abstract included in electronic submission form. Includes bibliographical references (p. ) and index.

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