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Showing 1 to 20 of 22 for “"isotope ratio mass spectrometry"”.
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The Potential of Bulk and Amino-Acid Specific Isotope Ratio Mass Spectrometry of Human Hair in Forensic and Clinical Applications
Isotope Ratio Mass Spectrometry (IRMS) is a specialized technique used to measure the isotopic ratios at natural abundance of the non-radioactive isotopes, and has proved to be a valuable tool in many applications. This research explores the use of IRMS of human hair for clinical and forensic …
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Stable isotope analysis: a new forensic science tool
… samples include Gas and Liquid Chromatography-Mass Spectrometry, infrared spectroscopy, thin layer chromatograph. In recent years, the development of the analytical technique isotope ratio mass spectrometry (IRMS) has increased the information obtainable regarding sample origin and …
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Developing elemental and isotope analytical methods for bacterial investigations
… and safety industry. This study uses Stable Isotope and Trace Element (SITE) analysis to differentiate between bacteria B. subtilis and B. cereus. This will also aid in the identification of the production method and determine the geographical origin of the bacterium. The study used …
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Microscopic Sampling of Dentine and Bone Collagen: Development of Sampling Methods for Carbon and Nitrogen Isotope Analysis
… throughout that time. As the technology for isotope ratio mass spectrometry analysis improves, the sampling methods should improve as well. This research focused on developing a new incremental dentine collagen sampling method and bone collagen microsampling method for stable isotope …
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Microscopic Sampling of Dentine and Bone Collagen: Development of Sampling Methods for Carbon and Nitrogen Isotope Analysis
… throughout that time. As the technology for isotope ratio mass spectrometry analysis improves, the sampling methods should improve as well. This research focused on developing a new incremental dentine collagen sampling method and bone collagen microsampling method for stable isotope …
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Microbial carbon sources on the shelf and slope of the northwestern Gulf of Mexico
… past five years, gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) analyses of phospholipid fatty acids (PLFAs) has been increasingly used to link organic matter (OM) sources with sedimentary bacteria. This technique has been applied across diverse estuarine and coastal …
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Organic residue analysis of Red Lustrous Wheelmade Ware vessels traded across the eastern Mediterranean during the Late Bronze Age
… study were re-examined. Gas chromatography-mass spectrometry identified four materials ¿ beeswax, bitumen, fat/oil and resin. Beeswax, found only in vessels from Hittite sites in Turkey, was probably used as a post-firing treatment. Fat/oil, present in some sherds from every site, represents …
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A comprehensive chemical examination of methylamphetamine produced from pseudoephedrine extracted from cold medication
… evaluates the ability of gas chromatography mass spectrometry (GCMS), isotope ratio mass spectrometry (IRMS) and inductively coupled plasma mass spectrometry (ICPMS) to characterize methylamphetamine hydrochloride synthesised from precursors extracted from proprietary cold medication using …
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Organic residue analysis of Red Lustrous Wheelmade Ware vessels traded across the eastern Mediterranean during the Late Bronze Age
… study were re-examined. Gas chromatography-mass spectrometry identified four materials ¿ beeswax, bitumen, fat/oil and resin. Beeswax, found only in vessels from Hittite sites in Turkey, was probably used as a post-firing treatment. Fat/oil, present in some sherds from every site, represents …
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Organic matter preserved in modern ooids from Shark Bay and the Bahamas
… Analysis of radiocarbon by accelerator mass spectrometry of C02 liberated during incremental dissolution of ooid carbonate provided information about the timescale of ooid formation and the ages of these particular ooids: Highborne Cay ooids began forming at least 1,000 years ago, with a …
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Concentration and isotopic composition of marine nitrous oxide, in particular the oxygen-17 isotope excess
The oxygen isotope excess Δ(17O) is a potential tracer of biological nitrous oxide (N2O) cycling. This study presents the first measurements of Δ(17O) in marine N2O together with details about the design and development of a custom-built Gas Chromatography-Isotope Ratio Mass Spectrometry (GC-IRMS) …
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Beyond the vessel: Organic residue analysis of Late Bronze and Early Iron Age south-east European pottery
… in Slovenia and Croatia, by gas-chromatography mass spectrometry. Two methods of lipid extraction were compared in a pilot study compressing 30 potsherds from Kaptol (solvent vs. acid extraction). This study revealed that more information was obtained by acid extraction, thus it was selected as …
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Microbial carbon within and above exotic copper deposits in northern Chile : implications for ore genesis and exploration
… formation and to provide guidelines for the exploration for non-outcropping mineralisation. Two main sample suites were examined: chrysocolla-rich ores from the Huinquintipa and Mina Sur deposits; and soils overlying a paleochannel in the Huinquintipa area known to be mineralised. The samples were …
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Isotopic evidence for the cycling of nitrate and nitrous oxide in aquifers beneath an irrigated agricultural district using established and emerging measurement techniques
… when compared to the conventional method using isotope-ratio mass-spectrometry (IRMS). The primary aim of this thesis was to use established multiple stable and radioactive isotope tracers to elucidate the hydrogeochemical controls on the production and reduction of NO3- and N2O in aquifers …
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GC-C-IRMS : a new technique to characterize and correlate oils and source rocks
… in Canadian crude oils are analyzed by a new isotope technique called gas chromatography-combustion-isotope ratio mass spectrometry using an alumina substrate, a helium purge, and a liquid nitrogen trapping mechanism for volatile sample application. The oils chosen for this analysis originate …
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Sulfur, carbon, and oxygen isotopes of coexisting sulfides and carbonates in gas and oil seeps from the Gulf of Mexico
… record. This study employs in-situ sulfur isotope measurements by secondary ion mass spectrometry (SIMS) in authigenic sulfides associated with barites and carbonates, and isotope measurements of carbon and oxygen by isotope ratio mass spectrometry (IRMS) in coexisting carbonates from 5 …
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Towards a coupled δ18O sugar and δ2H n-alkane approach in paleoclimate research
… for δ18O using gas chromatography-pyrolysis-isotope ratio mass spectrometry (GC-Py-IRMS). Prior to coupling of the δ18O sugar and δ2H n-alkane results, the recently developed method for compound-specific δ18O analyses of the hemicellulose-derived sugars had to be validated. First …
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A Process-Based Nutrient Model for the Bedded Manure Pack of Confined Beef Systems
… a process-based model that predicts concentration and gaseous emission from the bedded manure pack of a confined beef cattle system, with respect to different bedding material, manure storage time, and ambient temperature. The model incorporated the data collected in three experiments …
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Development and Application of An Integrated GC-MS/MS and GC-IRMS Analytical Approach in Food Quality Evaluation
… consequence, fraudulent practices such as adulteration, substitution, dilution, and mislabelling have become more frequent. Reliable identification of authentic products and detection of fraudulent ones have therefore become important challenges for food control authorities, producers, and …
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CO2 and Isotope Flux Measurements above a Spruce Forest
… (NEE) and the investigation of the carbon mass balances of ecosystems. Such measurements require a high degree of quality control in order to prevent systematic errors. The determination of the annual sum of NEE and filling of data gaps is complicated by characteristic diurnal and seasonal …
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