Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 317 for “"Gas Chromatography Mass spectrometry"”.
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Gas Chromatography: Mass Spectrometry of Chemical Agents and Related Interferents
… been involved in developing a field-portable gas chromatography-mass spectrometry (GC-MS) system with solid phase microextraction (SPME) sampling for point detection of chemical agents. The objective is to minimize the analysis time between sampling and detection of a potential chemical …
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Gas chromatography/mass spectrometry response pattern analysis of volatile organics in soils
The purge-and-trap gas chromatographic/mass spectrometric methods used by government agencies and their contracting laboratories for the analysis of volatile organic compounds in soils require the addition of both surrogate and internal standards to the sample matrix just prior to purging the …
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Determination of pesticides and chloroanisoles in water samples using gas chromatography-mass spectrometry.
… analysis methods were developed for capillary gas chromatographs using electron capture detection. Variation in temperature conditions, ramp rates and carrier gas flow rates were made to optimise both the resolution and speed of analysis for mixtures of carbaryl (a carbamate), lindane (an …
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Analysis of accelerants by gas chromatography-mass spectrometry and cyclic voltammetry for biosensor development
… Accelerant standards were also analysed using Gas Chromatography - Mass Spectrometry and confirmed using current fire debris sample analysis standards.
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Development of gas chromatography/mass spectrometry analysis of urinary acylcarnitines : application to metabolism studies
… compounds which makes them unsuitable for direct gas chromatography (GC) and combined gas chromatography/mass spectrometry (GCIMS). The latter of these is the favoured technique for normal urinary organic acid assays and is ideal in terms of selectivity and sensitivity. The work reported here …
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Quantification of short-chain fatty acids in cecal material by gas chromatography-mass spectrometry
… and derivatized for quantitative measurement by gas chromatography-mass spectrometry. Antibiotic-treated animals gavaged with <em>Candidaalbicans</em> had a lower level of cecal butyrate relative to untreated animals, but a higher level of butyrate when treated mice were also administered …
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Analytical Approaches for Analyzing Microplastics Using Pyrolysis Gas Chromatography Mass Spectrometry and Accelerated Solvent Extraction
… act as major sinks for microplastics, yet robust mass-based quantification of polymer composition in these complex matrices remains analytically challenging. This study applies an integrated accelerated solvent extraction (ASE) and pyrolysis–gas chromatography–mass spectrometry (Py-GCMS) workflow …
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DEVELOPMENT AND APPLICATION OF MINIATURIZED SAMPLE PREPARATION TECHNIQUES COMBINED WITH GAS CHROMATOGRAPHY-MASS SPECTROMETRY IN ENVIRONMENTAL ANALYSIS
This dissertation presents the development and application of miniaturized sample preparation techniques for environmental analysis. For sorbent-based microextraction, the applicability and feasibility of graphene or modified graphene as sorbent was investigated and evaluated. The possibility of …
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Development of a sample enrichment probe method for the gas chromatography-mass spectrometry analysis of hormones in water
… I 7P-estradiol and testosterone) in water using gas chromatography-mass spectrometry (GC-MS). SEPs constructed of thin stainless steel rods of inert material or sections of a polyimide coated megabore GC column provided at one end with a short sleeve of polydimethylsiloxane (PDMS) rubber as the …
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Characterisation of sandalwood essential oils using high performance thin-layer chromatography and high resolution gas chromatography mass spectrometry
… both within and across Santalum species. Gas Chromatography-Mass Spectrometry (GC-MS) is a technique commonly used to identify and quantify sesquiterpene compounds in sandalwood essential oils. High Performance Thin-Layer Chromatography (HPTLC) has yet to be fully explored as an …
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Detection and analysis of spin trapped radical adducts using thermal desorption gas chromatography mass spectrometry (TD-GC-MS)
… ParamagneticResonance (EPR) spectroscopy or Mass Spectrometry (MS). In the current study, Fenton chemistry has been used to generate hydroxyl radicals. Sincethe hydroxyl radical adduct of the spin-trap N-tert-butyl-α-phenylnitrone (PBN) is shortlivedat room temperature a secondary trapping …
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Methyl esterification of fatty acids and eicosanoids with a novel reagent trimethylsilyldiazomethane for analysis by gas chromatography-mass spectrometry
<p>Fatty acids are compounds with limited water solubility that belong to the lipid class of bio-organic compounds and can be utilized as a source of energy by the body or as precursors to oxidized compounds that have roles in inflammation and in the regulation of vascular tone. The prostaglandins …
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Test burning of carpet and foam and potential interferences in identifying petrol in arson investigation by gas chromatography/ mass spectrometry
… different burning tests and the evaluation, by gas chromatography/ mass spectrometry (GC/MS), of the burnt residues for the purpose of identifying compounds which may potentially interfere with the identification of petrol in arson investigation.
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Characterization of human expired breath by solid phase microextraction and analysis using gas chromatography-mass spectrometry and differential mobility spectrometry
… of human expired breath was developed using gas chromatography-mass spectroscopy. It was subsequently adopted for gas chromatography-differential mobility spectroscopy, a modality not previously applied to this problem. Tedlar bags and solid-phase microextraction were used for breath sampling …
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Comparison of Supported Liquid Extraction and Solid Phase Extraction of Methamphetamine from Urine and Method Validation by Gas Chromatography-Mass Spectrometry
… with detection and quantitation using GC-MS (gas chromatography- mass spectrometry). The SLE cartridges provide better analyte recoveries, eliminate emulsion formation, and allow for shorter processing time than other extraction techniques. The SPE cartridges used have a mixed-mode …
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Survey of Flavonoids and Their Distribution in Different Kinds of Onions Using High Performance Liquid Chromatography and Gas Chromatography Mass Spectrometry.
… analyzed subsequently by high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GCMS). Statistical calculations were done to see if there are significant differences in the varieties of onions studied from the chromatographic profiles obtained. The chromatograms …
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Characterization of human skin emanations by Solid Phase Microextraction (SPME) extraction of volatiles and subsequent analysis by Gas Chromatography-Mass Spectrometry (GC-MS)
An experimental study was performed to develop and validate a collection and analysis protocol for human skin emanations. The protocol developed included the rubbing of glass beads on the palms and backs of hands for 20 minutes. The volatile headspace above samples were extracted by a solid-phase …
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