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 50 for “"GC-FID"”.
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Analysis of Biogenic Amines by GC/FID and GC/MS
… are difficult to analyze by Gas Chromatography (GC) due to their lack of volatility and their interaction with the GC column, often leading to significant tailing and poor reproducibility. Biogenic amines need to be derivatized before both GC and HPLC analyses. The objective of this research was …
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Development of a headspace solid-phase microextraction (HS-SPME) procedure for the determination of short-chain fatty acids (SCFAs) in activated sludge by GC-FID
<p>The process of wastewater treatment includes the removal of inorganic solids such as sand and gravel as well as organic materials, phosphorus, and nitrogen. Activated sludge, containing a variety of living organisms, is added into the wastewater treatment system. Short-chain fatty acids (SCFAs), …
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Evaluation of Initial Flavor Fade in Fresh Roasted Peanuts using Gas Chromatography-Flame Ionization Detection, Gas Chromatography-Olfactometry, Sensory Analysis, and Chemosensory Techniques
… from oxidation were also evaluated using GC-FID to quantify and identify the pyrazines and hexanal over a 21 day storage period. Electronic Nose was used to determine differences between storage periods. Gas chromatography-Olfactometry identified potent pyrazines contributing to fresh …
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The development of physico-chemical quality control methods for Haemophilus influenzae type b vaccine production
… chromatography with flame ionisation detection (GC-FID) is a conventional technique used for the analysis of volatile analytes. The analysis of process residuals ethanol and ethylene glycol were performed using headspace or direct injection GC-FID analysis. Ethylene glycol, a non-volatile …
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Stanovení vonných látek s alergenními účinky
… V praktické části je využita metoda SPME-GC-FID ke stanovení vonných látek s alergenními účinky ve vybraných kosmetických přípravcích (přírodní krémy a toaletní vody).
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Biofilm-related Materials as Total N-nitrosamine (TONO) Precursors and Hydroxylamine-based Interferences in TONO and N-nitrosodimethylamine (NDMA) Measurements
… related to the TONO assay (Untreated, HgCl2 only, sulfanilamide [SAA] only, HgCl2 + SAA, and HCl) in terms of aqueous phase TONO, SPE-TONO and NDMA by GC-FID. A series of batch reactor experiments were performed with various combinations of 3.52 mM hydroxylamine, 35.2 mM dimethylamine (a …
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Appraisal and validation of rapid, integrated chemical and biological assays of environmental quality
… and biological markers to assess pollution. GC-ECD/FID/MS have been used to investigate the status of chemical contamination of the Black Sea by organochlorine residues, hydrocarbons and faecal sterols. Useful information is provided and problems with e.g. HCHs and sewage contamination are …
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Benzen v benzinech z hlediska ochrany zdraví
… s plamenově ionizačním detektorem (GC/FID) a metodou vysokoúčinné kapalinové chromatografie s detektorem diodového pole (HPLC/DAD). Okrajově se práce zaměřila také na stanovení toluenu (v červnu 2007 vstoupila v platnost vyhláška č. 284/2006 Sb., která zakazuje, aby byly …
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Towards a Membrane Electrode Assembly for a Thermally Regenerative Fuel Cell
… be proved by EIS or CV on the fuel cell, or by GC-FID of the cathode effluent. Other unknown products were seen in the GC-FID spectrum of the cathode effluent. Therefore, it is possible that the propiophenone did reduce at the cathode but it produced an unknown product. In conclusion, the …
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Estrazione di composti biologicamente attivi da piante della Sardegna
… of different chromatographic techniques such as GC-MS, GC-FID and HPLC. Concerning the main results, the supercritical extraction at 250 bar on Salvia desoleana aerial parts allowed us to obtain an extract containing a relevant amount of sclareole: 811 μg/mg, determined by the internal standard …
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Determination of ground-water tracer 2,6-difluorobenzoic acid by Gc/Ms
In this study, a GC analytical method for the determination of the ground water tracer, 2,6-difluorobenzoic acid (2,6-DFBA) at the part per billion level was established. Three sample preparation methods, which include two methylation methods and one silylation method, have been evaluated. …
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Oil Dries: A New Absorbent Material For Collection Of Ignitable Liquids From Semi-Porous Material
… coupled with flame ionization detection (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). Chromatograms obtained from both oil dries for the various ignitable liquids used, resembled the chromatograms for the respective neat standards. This demonstrates that these …
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Senzorická kvalita francouzského plísňového sýra Brie de Meaux v souvislosti s jeho chemickým a mikrobiálním složením
… a při 20 °C. Vzorky byly hodnoceny pomocí SPME-GC-MS z pohledu těkavých (aromatických) látek. Mastné kyseliny byly identifikovány a kvantifikovány pomocí GC-FID po převedení na methylestery pomocí BF3. Pro mikrobiální profil byla využita metoda RT-PCR. Ve vzorcích bylo identifikováno 59 těkavých …
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Προσδιορισμός Βιταμίνης Ε σε προϊόντα δημητριακών
… σε συνδυασμό με ανιχνευτή ιονισμού φλόγας (GC- FID) για τον προσδιορισμό της βιταμίνης Ε σε προϊόντα δημητριακών, βασιζόμενη σε μέθοδο που παρουσίασαν οι Pyka et al. (2001) για τον προσδιορισμό α-τοκοφερόλης σε ανθρώπινο πλάσμα, τροποποιημένη για τον προσδιορισμό α-τοκοφερόλης σε προϊόντα …
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Zebra GC: A Fully Integrated Micro Gas Chromatography System
… of microfabricated gas chromatography (microGC) system characterized for detecting hazardous air pollutants (HAPs) at parts-per-billion (ppb) concentrations in complex mixtures has been described. A microfabricated preconcentrator (microPC), a MEMS separation column with on-chip thermal …
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Analysis of wood pulp extracts utilizing gas chromatography-mass spectroscopy
… extracts were then compared qualitatively using GC-FID and GC-MSD as well as quantitatively based on the percent of extractives obtained. For all the pulps studied, the percent extractives of water > ethyl acetate > cyclohexane. The CTMP extracts exhibited many more components as compared to BKP …
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Hepatic microsomal and peroxisomal docosahexaenoate biosynthesis during piglet development
… detected by gas chromatograph-mass spectrometer (GC-MS). The quantity of each fatty acid was detemiined by gas chromatograph-flame ionization detector (GC-FID) and synthesis of each fatty acid was calculated for a 30-minute period. Synthesis of DHA was not detected in fetal liver. The data …
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Residual Diesel Range Organics and Selected Frothers in Process Waters from Fine Coal Flotation
… with either a flame ionization detector (GC-FID) or a mass spectrometer (GC-MS). Samples are subjected to a variety of test conditions in order to understand the behavior of diesel compounds in coal processing streams. Results show that frother and collector reagents are not likely to …
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Kinetic analysis of thiol oxidation to study the effects of fluorinated groups on metal phthalocyanine catalysts
The oxidation of thiol (RSH) to disulfide (RSSR) is important biologically and industrially. Corrosive and malodorous thiols exist as contaminants in wastewater discharge from mining facilities, pulp and paper mills, tanneries, and oil refineries. The elimination of thiols from petroleum products …
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