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Showing 1 to 15 of 15 for “"GCxGC"”.
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Two-dimensional gas chromatography : a novel technique for iron low temperature Fischer-Tropsch selectivity studies
… two-dimensional gas chromatography (GCxGC) it may now be possible to analyze the complex Fischer-Tropsch products in a relatively short time while delivering good separation of even minor compounds such as oxygenates and branched compounds. The aim of this study was to investigate if …
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Analysis of the volatile organic compounds produced by the decomposition of pig carcasses and human remains
… time-of-flight mass spectrometry (TD-GCxGC-TOFMS). The additional peak capacity and spectral deconvolution of the GCxGC-TOFMS system generated a characteristic profile of decomposition VOCs across the various stages of soft tissue decomposition. The profile was comprised of numerous …
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Quantification of pyrethroid and organophosphate metabolites in hair and urine samples of rural children from the Western Cape, South Africa using the two-dimensional gas chromatography-mass spectrometry
… with a time-of-flight mass spectrometry (2-D GCxGC TOF/MS) based method, specifically designed for analysis of compounds in complex matrices such as urine and hair matrices. Furthermore, the 2D GCxGC TOF/MS was available in-house and proved to be less expensive than outsourcing an analysis …
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Chemistry of alkylaromatics in crude oil upgrading
… 75 creates several hundred products resolved by GCxGC, and the analysis is intractable if one considers only the experimental data, which does not reveal reactive intermediates or reaction paths.
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Application of Polychlorinated Biphenyl Signatures for Environmental Fingerprinting
… with time of flight mass spectrometry (GCxGC-ToFMS) method was designed and optimised to provide a congener specific method capable of identifying 200 out of the 209 PCBs, with detection limits in human serum in the range of 1 to 10 ng g-1 lipid. The extraction and detection methods were …
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Studies of the interaction of biogenic volatile organic compounds and NOx in forest environments
… The development of a novel sampling system for a GCxGC system is presented, along with data obtained by the instrument during a field campaign. Finally, a 0-D chemical model is used to identify the BVOC precursors most important to the formation of organic nitrates.</p>
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The effect of different sample preparatory protocols on the induction of the aryl hydrocarbon receptor (AhR) in the H4IIE–luc reporter gene bio–assay
… coupled to time of flight mass spectrometry (GCxGC-TOFMS). Instrumental results indicated a high level of PAHs in the extracts, which could lead to super induction of the aryl hydrocarbon receptor (AhR) and therefore, to a positive bias in the results. Instrumental screening proved that all …
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Supercritical Water desulfurization of crude oil
… analyzed with comprehensive gas chromatography (GCxGC) coupled with two detectors, sulfur chemiluminescence detector (SCD) and a flame ionization detector (FID). SCD is a sulfur specific detector that allowed detailed analysis of the reactions that occur during SCW treatment of real fuel …
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Development of a sampling system for the collection of exhaled breath condensates and its subsequent analysis using 2-dimensional gas chromatography
… as well as two-dimensional gas chromatography (GCxGC). This provides analysis of volatile organic compounds as well as proteins and higher molecular weight components present in breath. This broader analysis might find use in medical diagnostics, for detection of markers indicating oxidative …
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Synthesis, Fractionation, Characterisation and Toxicity of Naphthenic Acids from Complex Mixtures
… gas chromatography-mass spectrometry (GCxGC-MS). Reference acids were then either purchased, or more commonly, where they were not commercially-available, synthesised, mainly by micro-hydrogenation methods, for co-chromatography and comparison of mass spectra of methyl esters with those …
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QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) Extraction – Gas Chromatography for the Analysis of Drugs
… of hormones from water using GC-MS/MS and GCxGC-TOFMS including a comparison of QuEChERS to solid phase microextraction (SPME) using GC-MS/MS, and finally the extraction of drugs of abuse from synthetic urine.</p>
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Comprehensive study of a heavy fuel oil spill : modeling and analytical approaches to understanding environmental weathering
… analyzed with comprehensive two-dimensional GC (GCxGC) and a physiochemical model developed to approximate quantitative apportionment of compounds lost to the atmosphere and water. Model results suggest temperature is the primary control of evaporation. Finally, to examine the prominent non-GC …
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Biodegradation, water solubility and characterisation studies of unresolved complex mixtures (UCMs) of aromatic hydrocarbons
… chromatography-time of flight-mass spectrometry (GCxGC-ToF-MS) analysis was used to provide vastly increased separation power and characterisation of a water 'soluble' monoaromatic UCM. Over 1200 compounds were separated by the chromatography, of which about 500 had distinct mass spectra from the …
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On the bicyclic acids of petroleum
The identification of petroleum acids, also known as ‘naphthenic’ acids (NA), has been an analytical challenge for over 140 years. However, most recent interest in NA has arisen due to concerns over their presence and apparent associated toxic effect in oil platform produced waters and oil sands …
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Application of Adverse Outcome Pathway framework in assessing nanogold exposure to Daphnia magna
… coupled with time of flight mass spectrometry (GCxGC-TOF-MS). Multivariate analyses was done using MetaboAnalyst software to statistically identify the unique metabolites produced following exposure to the nAu and ionic Au and determine which metabolic pathways (MIE) were influenced The KEs were …