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https://www.readbyqxmd.com/read/28315805/comprehensive-composition-of-creosote-using-comprehensive-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry-gcxgc-tofms
#1
Christopher Gallacher, Russell Thomas, Christopher Taylor, Richard Lord, Robert M Kalin
Creosote is a distillation product of coal tar and is widely used as wood preservative for railway sleepers, utility poles and for other applications. Creosote can have potentially negative effects on the environment and many of the components are toxic. This study presents the analysis of a Creosote sample from a former wood impregnation plant located in the UK. The sample was analysed using two dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) and a database of compounds that could be detected was produced...
March 13, 2017: Chemosphere
https://www.readbyqxmd.com/read/28302985/application-of-laser-ionization-time-of-flight-mass-spectrometry-for-the-direct-measurement-of-a-silane-coupling-agent-in-slurries
#2
Takaaki Fujii, Tomohiro Uchimura
Laser ionization time-of-flight mass spectrometry (LI-TOFMS) was applied to the direct measurement of a silane coupling agent in slurries. In the present study, a slurry with dispersed TiO2 nanoparticles treated with phenyltriethoxysilane (PTES) was prepared. As a result, the peaks for PTES could be observed from the slurry sample containing unreacted PTES, and no peaks were observed from the slurry sample where unreacted PTES was removed by washing. This method can be used to directly analyze surface coating agents, such as PTES in slurries, and would be useful for obtaining a direct understanding of the characteristics of slurries...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/28302542/clinical-implications-associated-with-the-posttranslational-modification-induced-functional-impairment-of-albumin-in-oxidative-stress-related-diseases
#3
REVIEW
Hiroshi Watanabe, Tadashi Imafuku, Masaki Otagiri, Toru Maruyama
Recent research findings indicate that the posttranslational modification of human serum albumin (HSA) such as oxidation, glycation, truncation, dimerization and carbamylation is related to certain types of diseases. We report herein on a simple and rapid analytical method, using an ESI-TOFMS technique, that allows posttranslational modifications of HSA to be quantitatively and qualitatively evaluated with a high degree of sensitivity. In patients with chronic liver disease, chronic renal disease and diabetes mellitus, an increase in the level of oxidized Cys-34 of HSA accompanied by a decrease in the level of reduced Cys-34 was observed...
March 13, 2017: Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28274593/in-depth-compositional-analysis-of-water-soluble-and-insoluble-organic-substances-in-fine-pm2-5-airborne-particles-using-ultra-high-resolution-15t-ft-icr-ms-and-gc%C3%A3-gc-tofms
#4
Jung Hoon Choi, Jijeong Ryu, Sodam Jeon, Jungju Seo, Yung-Hun Yang, Seung Pil Pack, Sungwook Choung, Kyoung-Soon Jang
Airborne particulate matter consisting of ionic species, salts, heavy metals and carbonaceous material is one of the most serious environmental pollutants owing to its impacts on the environment and human health. Although elemental and organic carbon compounds are known to be major components of aerosols, information on the elemental composition of particulate matter remains limited because of the broad range of compounds involved and the limits of analytical instruments. In this study, we investigated water-soluble and -insoluble organic compounds in fine (PM2...
March 5, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28256828/three-dimensional-reconstruction-of-the-tissue-specific-multielemental-distribution-within-ceriodaphnia-dubia-via-multimodal-registration-using-laser-ablation-icp-mass-spectrometry-and-x-ray-spectroscopic-techniques
#5
Stijn J M Van Malderen, Brecht Laforce, Thibaut Van Acker, Charlotte Nys, Maarten De Rijcke, Riet de Rycke, Michiel De Bruyne, Matthieu N Boone, Karel De Schamphelaere, Olga Borovinskaya, Björn De Samber, Laszlo Vincze, Frank Vanhaecke
In this work, the three-dimensional elemental distribution profile within the freshwater crustacean Ceriodaphnia dubia was constructed at a spatial resolution down to 5 μm via a data fusion approach employing state-of-the-art laser ablation-inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOFMS) and laboratory-based absorption microcomputed tomography (μ-CT). C. dubia was exposed to elevated Cu, Ni, and Zn concentrations, chemically fixed, dehydrated, stained, and embedded, prior to μ-CT analysis...
March 16, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28256041/metabolic-characterization-of-invaded-cells-of-the-pancreatic-cancer-cell-line-panc-1
#6
Mayumi Fujita, Kaori Imadome, Takashi Imai
We previously reported that about 0.4% of cells in the cultured human pancreatic cancer cell line, PANC-1, can invade matrigel during the transwell invasion assay, suggesting that these invaded PANC-1 cells may have specific characteristics to keep their invasive potential. To identify the metabolic characterization specific in the invaded PANC-1 cells, metabolome analysis of the invaded PANC-1 compared with the whole cultured PANC-1 was performed using CE-TOFMS, and concentrations of 110 metabolites were measured...
March 3, 2017: Cancer Science
https://www.readbyqxmd.com/read/28245644/quantitation-of-4-methyl-4-sulfanylpentan-2-one-4msp-in-hops-by-a-stable-isotope-dilution-assay-in-combination-with-gc%C3%A3-gc-tofms-method-development-and-application-to-study-the-influence-of-variety-provenance-harvest-year-and-processing-on-4msp-concentrations
#7
Klaas Reglitz, Martin Steinhaus
A stable isotope dilution assay was developed for quantitation of 4-methyl-4-sulfanylpentan-2-one (4MSP) in hops. The approach included the use of 4-((13)C)methyl-4-sulfanyl(1,3,5-(13)C3)pentan-2-one as internal standard, selective isolation of hop thiols by mercurated agarose, and GC×GC-TOFMS analysis. Application of the method to 53 different hop samples revealed 4MSP concentrations between <1 and 114 μg/kg. Notably high concentrations were associated with United States varieties such as Citra, Eureka, Simcoe, and Apollo, whereas 4MSP was absent from traditional German and English varieties...
March 8, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28208275/comprehensive-three-dimensional-gas-chromatography-with-time-of-flight-mass-spectrometry
#8
Nathanial E Watson, H Daniel Bahaghighat, Ke Cui, Robert E Synovec
Development of comprehensive, three-dimensional (3D) gas chromatography with time-of-flight mass spectrometric detection (GC(3)/TOFMS) is described. This instrument provides four dimensions (4D) of chemical selectivity and includes significant improvements to total selectivity (mass spectrometric and chromatographic), peak identification, and operational temperature range relative to previous models of the GC(3) reported. The new instrumental design and data output are evaluated and illustrated via two samples, a 115-component test mixture and a diesel fuel spiked with several compounds, for the purpose of illustrating the chemical selectivity benefits of this instrumental platform...
February 7, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28207236/using-receiver-operating-characteristic-curves-to-optimize-discovery-based-software-with-comprehensive-two-dimensional-gas-chromatography-with-time-of-flight-mass-spectrometry
#9
Brooke C Reaser, Bob W Wright, Robert E Synovec
We report a quantitative approach to optimize implementation of discovery-based software for comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS). The software performs a tile-based Fisher ratio (F-ratio) analysis and facilitates a supervised nontargeted analysis based upon the experimental design to aid in the discovery of analytes with statistically different variances between sample classes. The quantitative approach for software optimization uses receiver operating characteristic (ROC) curves...
March 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28188804/metabolite-profiling-of-infection-associated-metabolic-markers-of-onchocerciasis
#10
Sasisekhar Bennuru, Sara Lustigman, David Abraham, Thomas B Nutman
The global efforts for onchocerciasis elimination may require additional tools (safe micro and macrofilaricidal drugs, vaccines and biomarkers) as elimination efforts move toward the "end game". Efforts toward the identification of suitable biomarkers have focused on specific protein(s) and/or nucleic acids, but metabolites present an alternative option as they have limited half-lives and are the result of combinatorial effects. In comparison to previously used methodology of LC-MS for metabolomic approaches, we used a non-targeted capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) to analyze the serum metabolic profiles of Ov-infected and -uninfected individuals (n=20)...
February 8, 2017: Molecular and Biochemical Parasitology
https://www.readbyqxmd.com/read/28173924/chemometric-analysis-of-comprehensive-two-dimensional-gas-chromatography-mass-spectrometry-metabolomics-data
#11
Yahya Izadmanesh, Elba Garreta-Lara, Jahan B Ghasemi, Silvia Lacorte, Victor Matamoros, Roma Tauler
Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) is a powerful tool for separation and identification of analytes in complex natural samples. In this paper, different chemometric methods were compared for fast non-targeted GC×GC-TOFMS metabolomic profiling of the crustaceous species Daphnia magna and a general chemometric strategy and workflow is proposed. The strategy proposed in this work combined the compression of GC×GC-TOFMS data matrices in the retention time direction using wavelets and the appropriate column-wise data matrix augmentation arrangement, and its modeling by Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS)...
March 10, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28153256/characterization-of-thin-film-tandem-solar-cells-by-radiofrequency-pulsed-glow-discharge-time-of-flight-mass-spectrometry
#12
Beatriz Fernandez, Lara Lobo, Nies Reininghaus, Rosario Pereiro, Alfredo Sanz-Medel
Beside low production costs and the use of nontoxic and abundant raw materials, silicon based thin-film solar cells have the advantage to be built up as multi junction devices like tandem or triple junction solar cells. Silicon thin film modules made of tandem cells with hydrogenated amorphous silicon (a-Si:H) top cell and microcrystalline (μc) Si:H bottom cell are available on the market. In this work, the analytical potential of state-of-the art radiofrequency (rf) pulsed glow discharge (PGD) time of flight mass spectrometry (TOFMS) commercial instrumentation is investigated for depth profiling analysis of tandem-junctions solar cells on 2mm thick glass substrate with 1µm thick ZnO:Al...
April 1, 2017: Talanta
https://www.readbyqxmd.com/read/28121990/colonic-absorption-of-low-molecular-weight-metabolites-influenced-by-the-intestinal-microbiome-a-pilot-study
#13
Mitsuharu Matsumoto, Takushi Ooga, Ryoko Kibe, Yuji Aiba, Yasuhiro Koga, Yoshimi Benno
Low-molecular-weight metabolites produced by the intestinal microbiome play a direct role in health and disease. However, little is known about the ability of the colon to absorb these metabolites. It is also unclear whether these metabolites are bioavailable. Here, metabolomics techniques (capillary electrophoresis with time-of-flight mass spectrometry, CE-TOFMS), germ-free (GF) mice, and colonized (Ex-GF) mice were used to identify the colonic luminal metabolites transported to colonic tissue and/or blood...
2017: PloS One
https://www.readbyqxmd.com/read/28118975/feasibility-of-ultra-performance-liquid-chromatography-ion-mobility-time-of-flight-mass-spectrometry-in-analyzing-oxysterols
#14
Petri Kylli, Thomas Hankemeier, Risto Kostiainen
Oxysterols are oxygenated cholesterols that are important in many cell functions and they may also be indicative of certain diseases. The purpose of this work was to study the feasibility of ultra-performance liquid chromatography-ion mobility-time-of-flight mass spectrometry (UPLC-IM-TOFMS) using traveling wave cell in analyzing oxysterols and especially their isomers in biological samples. Oxysterols were analyzed as their p-toluenesulfonyl isocyanate derivatives, which improved the separation of isomeric oxysterols by ion mobility and ionization efficiency in the electrospray ionization step...
March 3, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28110945/elucidation-of-the-aroma-compositions-of-zhenjiang-aromatic-vinegar-using-comprehensive-two-dimensional-gas-chromatography-coupled-to-time-of-flight-mass-spectrometry-and-gas-chromatography-olfactometry
#15
Zhilei Zhou, Shuangping Liu, Xiangwei Kong, Zhongwei Ji, Xiao Han, Jianfeng Wu, Jian Mao
In this work, a method to characterize the aroma compounds of Zhenjiang aromatic vinegar (ZAV) was developed using comprehensive two dimensional gas chromatography (GC×GC) coupled with time-of-flight mass spectrometry (TOFMS) and gas chromatography olfactometry (GC-O). The column combination was optimized and good separation was achieved. Structured chromatograms of furans and pyrazines were obtained and discussed. A total of 360 compounds were tentatively identified based on mass spectrum match factors, structured chromatogram and linear retention indices comparison...
March 3, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28107982/quantification-of-real-thermal-catalytic-and-hydrodeoxygenated-bio-oils-via-comprehensive-two-dimensional-gas-chromatography-with-mass-spectrometry
#16
Raquel V S Silva, Nathalia S Tessarolo, Vinícius B Pereira, Vitor L Ximenes, Fábio L Mendes, Marlon B B de Almeida, Débora A Azevedo
The elucidation of bio-oil composition is important to evaluate the processes of biomass conversion and its upgrading, and to suggest the proper use for each sample. Comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) is a widely applied analytical approach for bio-oil investigation due to the higher separation and resolution capacity from this technique. This work addresses the issue of analytical performance to assess the comprehensive characterization of real bio-oil samples via GC×GC-TOFMS...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28088709/characterization-of-smokeless-powders-using-multiplexed-collision-induced-dissociation-mass-spectrometry-and-chemometric-procedures
#17
Kristen L Reese, A Daniel Jones, Ruth Waddell Smith
This work demonstrates a non-targeted mass spectrometry approach for identification of organic compounds in smokeless powders. Unburned powders were removed from various commercial ammunitions of different brand, primer composition, caliber, and age. The unburned powders and corresponding fired residues were analyzed by liquid chromatography-atmospheric pressure chemical ionization-time-of-flight mass spectrometry (LC-APCI-TOFMS). Multiplexed collision-induced dissociation was performed at increasing collision potentials resulting in successive fragmentation that provided structural information for compound identification in a non-targeted manner...
December 21, 2016: Forensic Science International
https://www.readbyqxmd.com/read/28029296/characterization-of-kewda-volatile-components-by-comprehensive-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry
#18
Noohi Nasim, Asit Ray, Subhashree Singh, Sudipta Jena, Ambika Sahoo, Basudeba Kar, I Sriram Sandeep, Sujata Mohanty, Sanghamitra Nayak
Kewda (Pandanus fascicularis Lam.) is a well known medicinal and aromatic plant. The paper aims to precisely characterize volatile constituents present in Kewda flower oil using comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry (GCxGC-TOFMS). A total of 159 components were identified due to enhanced chromatographic separation and mass spectral deconvolution of GCxGC-TOFMS. On the basis of its chemical structure, the identified compounds were grouped into hydrocarbons, alcohols, ethers, ketones, esters, nitrogen compounds, aldehydes, acids, lactones, halides and sulfur containing compounds...
April 2017: Natural Product Research
https://www.readbyqxmd.com/read/28028595/comprehensive-two-dimensional-gas-chromatographic-profiling-and-chemometric-interpretation-of-the-volatile-profiles-of-sweat-in-knit-fabrics
#19
A Paulina de la Mata, Rachel H McQueen, Seo Lin Nam, James J Harynuk
Human axillary sweat is a poorly explored biofluid within the context of metabolomics when compared to other fluids such as blood and urine. In this paper, we explore the volatile organic compounds emitted from two different types of fabric samples (cotton and polyester) which had been worn repeatedly during exercise by participants. Headspace solid-phase microextraction (SPME) and comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) were employed to profile the (semi)volatile compounds on the fabric...
March 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28011407/non-steroidal-anti-inflammatory-drugs-in-the-watercourses-of-elbe-basin-in-czech-republic
#20
Petr Marsik, Jan Rezek, Monika Židková, Barbora Kramulová, Jan Tauchen, Tomáš Vaněk
Non-steroidal anti-inflammatory drugs (NSAIDs) belong to most used pharmaceuticals in the human and veterinary medicine. The widespread consumption of NSAIDs has led to their ubiquitous occurrence in water environment including large river systems. In the present study, concentrations of the five most frequently used NSAIDs (ibuprofen, diclofenac, naproxen, ketoprofen and indomethacin) were determined in the watercourses of the river Elbe basin in Czech Republic. The presence of the pharmaceuticals was measured at 29 sampling sites including urban and rural areas, small creeks and main tributaries of the Elbe monthly from April to December of 2011...
December 14, 2016: Chemosphere
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