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https://www.readbyqxmd.com/read/28811030/targeted-analyte-deconvolution-and-identification-by-four-way-parallel-factor-analysis-using-three-dimensional-gas-chromatography-with-mass-spectrometry-data
#1
Nathanial E Watson, Sarah E Prebihalo, Robert E Synovec
Comprehensive three-dimensional gas chromatography with time-of-flight mass spectrometry (GC(3)-TOFMS) creates an opportunity to explore a new paradigm in chemometric analysis. Using this newly described instrument and the well understood Parallel Factor Analysis (PARAFAC) model we present one option for utilization of the novel GC(3)-TOFMS data structure. We present a method which builds upon previous work in both GC(3) and targeted analysis using PARAFAC to simplify some of the implementation challenges previously discovered...
August 29, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28747703/linking-the-morphological-and-metabolomic-response-of-lactuca-sativa-l-exposed-to-emerging-contaminants-using-gc%C3%A2-%C3%A3-%C3%A2-gc-ms-and-chemometric-tools
#2
Carlos Hurtado, Hadi Parastar, Víctor Matamoros, Benjamín Piña, Romà Tauler, Josep M Bayona
The occurrence of contaminants of emerging concern (CECs) in irrigation waters (up to low μg L(-1)) and irrigated crops (ng g(-1) in dry weight) has been reported, but the linkage between plant morphological changes and plant metabolomic response has not yet been addressed. In this study, a non-targeted metabolomic analysis was performed on lettuce (Lactuca sativa L) exposed to 11 CECs (pharmaceuticals, personal care products, anticorrosive agents and surfactants) by irrigation. The plants were watered with different CEC concentrations (0-50 µg L(-1)) for 34 days under controlled conditions and then harvested, extracted, derivatised and analysed by comprehensive two-dimensional gas chromatography coupled to a time-of-flight mass spectrometer (GC × GC-TOFMS)...
July 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28741793/telomerase-enzyme-deficiency-promotes-metabolic-dysfunction-in-murine-hepatocytes-upon-dietary-stress
#3
Raquel M Alves-Paiva, Sachiko Kajigaya, Xingmin Feng, Jichun Chen, Marie Desierto, Susan Wong, Danielle M Townsley, Flávia S Donaires, Adeline Bertola, Bin Gao, Neal S Young, Rodrigo T Calado
Short telomeres and genetic telomerase defects are risk factors for some human liver diseases, ranging from non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) to cirrhosis. In murine models, telomere dysfunction has been shown to metabolically compromise hematopoietic cells, liver, and heart via the activation of the p53-PGC axis METHODS: Tert- and Terc-deficient mice were challenged with liquid high fat diet (HFD). Liver metabolic contents were analyzed by CE-TOFMS and liver fat content was confirmed by confocal and electronic microscopy RESULTS: Tert-deficient but not Terc-deficient mice develop hepatocyte injury and frank steatosis when challenged with liquid HFD...
July 25, 2017: Liver International: Official Journal of the International Association for the Study of the Liver
https://www.readbyqxmd.com/read/28741270/involvement-of-porphyromonas-gingivalis-in-the-progression-of-non-alcoholic-fatty-liver-disease
#4
Takashi Nakahara, Hideyuki Hyogo, Atsushi Ono, Yuko Nagaoki, Tomokazu Kawaoka, Daiki Miki, Masataka Tsuge, Nobuhiko Hiraga, Clair Nelson Hayes, Akira Hiramatsu, Michio Imamura, Yoshiiku Kawakami, Hiroshi Aikata, Hidenori Ochi, Hiromi Abe-Chayama, Hisako Furusho, Tomoaki Shintani, Hidemi Kurihara, Mutsumi Miyauchi, Takashi Takata, Koji Arihiro, Kazuaki Chayama
BACKGROUND AND AIMS: The risk factors in the progression of nonalcoholic fatty liver disease (NAFLD) have not been fully clarified. Porphyromonas gingivalis (P.g) has been considered to be a confounding risk factor for systemic diseases. We aimed to evaluate the effect of P.g infection on risk of progression to NASH. METHODS: (1) Serum IgG antibody titers against P.g fimbriae (fimA) in 200 biopsy-proven NAFLD patients were measured by ELISA and compared with histological findings...
July 24, 2017: Journal of Gastroenterology
https://www.readbyqxmd.com/read/28717932/a-w-geometry-ortho-tof-ms-with-high-resolution-and-up-to-100-duty-cycle-for-ms-ms
#5
Igor V Chernushevich, Samuel I Merenbloom, Suya Liu, Nic Bloomfield
Orthogonal injection time-of-flight (orthoTOF) mass spectrometry (MS) is the most prevalent form of TOFMS, owing to its greater control over incoming ion energy, the ability to correct for aberrations in incoming ion velocity and position, and its ability to provide an entire mass spectrum within a single scan. However, the duty cycle of orthoTOFMS is low compared with scanning analyzers, which can have 100% duty cycle when measuring a single type of ion. Typical duty cycles for orthoTOFMS range from 1% to 30%, depending on instrument geometry...
July 17, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28712553/implications-of-phase-ratio-for-maximizing-peak-capacity-in-comprehensive-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry
#6
Brendon A Parsons, David K Pinkerton, Robert E Synovec
The relationship between the phase ratio, β, of the primary ((1)D) and secondary ((2)D) separation dimensions of comprehensive two-dimensional (2D) gas chromatography (GC×GC) separations, and the implications of β on realization of maximal 2D peak capacity, nc,2D, are examined. A GC×GC chromatographic system with time-of-flight mass spectrometry, TOFMS, was otherwise held constant for the separation of a multi-component test mixture spanning a range of chemical functionalities, while only the β of the two analytical columns were changed, (1)β for (1)D and (2)β for (2)D...
July 9, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28701067/metabolomic-approach-to-understand-the-acute-and-chronic-hepatotoxicity-of-veratrum-nigrum-extract-in-mice-based-on-ultra-high-performance-liquid-chromatography-coupled-with-quadrupole-time-of-flight-mass-spectrometry
#7
Ziheng Wei, Qingqing Qian, Xu Dong, Na Li, Guangchun Sun, Songyan Gao, Xin Dong
Veratrum nigrum L. (VN) is a poisonous traditional Chinese Medicine herb with thousands of years in China. Clinical studies have shown that VN has ability to cause hepatotoxicity, which severely limits its clinical use. The mechanism of its hepatotoxicity has not been fully elucidated. The purpose of this study was to develop and characterize a model of acute and chronic hepatotoxicity induced by Veratrum nigrum L. extract (VNE) to understand the mechanism by the liver tissue metabolomics approach based on ultra high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOFMS)...
July 13, 2017: Toxicology Mechanisms and Methods
https://www.readbyqxmd.com/read/28700098/comparison-of-species-classification-models-of-mass-spectrometry-data-kernel-discriminant-analysis-vs-random-forest-a-case-study-of-afrormosia-pericopsis-elata-harms-meeuwen
#8
V Deklerck, K Finch, P Gasson, J Van den Bulcke, J Van Acker, H Beeckman, E Espinoza
RATIONALE: The genus Pericopsis includes four tree species of which only Pericopsis elata (Harms) Meeuwen is of commercial interest. Enforcement officers might have difficulties discerning this CITES-listed species from some other tropical African timber species. Therefore, we tested several methods to separate and identify these species rapidly in order to enable customs officials to uncover illegal trade. In this study, two classification methods using DART TOFMS data to discern between several species are presented...
July 12, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28691762/comparison-of-fully-wettable-rplc-stationary-phases-for-lc-ms-based-cellular-metabolomics
#9
Le Si-Hung, Tim J Causon, Stephan Hann
Reversed-phase LC combined with high-resolution mass spectrometry (HRMS) is one of the most popular methods for cellular metabolomics studies. Due to the difficulties in analysing a wide range of polarities encountered in the metabolome, 100%-wettable reversed-phase materials are frequently used to maximise metabolome coverage within a single analysis. Packed with silica-based sub-3 μm diameter particles, these columns allow high separation efficiency and offer a reasonable compromise for metabolome coverage within a single analysis...
July 10, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28687801/altered-kyn-trp-gln-glu-and-met-methionine-sulfoxide-ratios-in-the-blood-plasma-of-medication-free-patients-with-major-depressive-disorder
#10
Hidehiro Umehara, Shusuke Numata, Shin-Ya Watanabe, Yutaka Hatakeyama, Makoto Kinoshita, Yukiko Tomioka, Kiyoshi Nakahara, Takeshi Nikawa, Tetsuro Ohmori
Capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS) is a comprehensive, quantitative, and high throughput tool used to analyze metabolite profiles. In the present study, we used CE-TOFMS to profile metabolites found in the blood plasma of 33 medication-free patients with major depressive disorder (MDD) and 33 non-psychiatric control subjects. We then investigated changes which occurred in the metabolite levels during an 8-week treatment period. The medication-free MDD patients and control subjects showed significant differences in their mean levels of 33 metabolites, including kynurenine (KYN), glutamate (Glu), glutamine (Gln), methionine sulfoxide, and methionine (Met)...
July 7, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28677846/analysis-of-oxovanadium-iv-complexes-using-electrospray-mass-spectrometry-molecular-ion-formed-by-loss-of-an-electron-and-its-product-ions-trapping-oxygen
#11
Xue Hou, Zhi-Jun Wu, Jian-Qiang Zhao, Wei-Cheng Yuan, Hua-Yi Qi
RATIONALE: In addition to their biological properties, oxovanadium complexes have been widely applied as catalysts because of their excellent catalytic-oxidation capability. Recently, monometallic oxovanadium(IV) complexes have been used as catalysts in the electrophilic trifluoromethylation of silyl ketene imines. The study of catalysts can contribute to an understanding of the reaction mechanism. METHODS: Six monometallic oxovanadium(IV) complexes were analyzed by electrospray ionization time-of flight mass spectrometry (ESI-TOFMS), and collision-induced dissociation mass spectrometry (CID-MS) experiments were conducted for selected cations [M](+) of oxovanadium(IV) complexes as well as a deuterium-labeled complex...
September 15, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28665029/impact-of-macroporosity-on-catalytic-upgrading-of-fast-pyrolysis-bio-oil-by-esterification-over-silica-sulfonic-acids
#12
Jinesh Manayil, Amin Osatiashtiani, Alvaro Mendoza, Christopher Parlett, Lee Durndell, Mark Isaacs, Chrysoula Michailof, Eleni Heracleous, Angelos Lappas, Adam Lee, Karen Wilson
Fast pyrolysis bio-oils possess unfavourable physicochemical properties and poor stability, due in large part to the presence of carboxylic acids, which hinders their use as biofuels. Catalytic esterification offers an atom and energy efficient route to upgrade pyrolysis bio-oils. Propyl sulfonic acid silicas are active for carboxylic acid esterification but suffer mass-transport limitations for bulky substrates. Macropore (200 nm) incorporation enhances the activity of mesoporous SBA-15 architectures (post-functionalised by hydrothermal saline promoted grafting) for the esterification of linear carboxylic acids, with the magnitude of turnover frequency (TOF) enhancement increasing with chain length from 5 % (C3) to 110 % (C12)...
June 30, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28641225/investigation-of-dissociation-constants-for-individual-and-total-naphthenic-acids-species-using-ultra-performance-liquid-chromatography-ion-mobility-time-of-flight-mass-spectrometry-analysis
#13
Rongfu Huang, Pamela Chelme-Ayala, Yanyan Zhang, Mohamed Changalov, Mohamed Gamal El-Din
Ultra-performance liquid chromatography ion mobility time-of-flight mass spectrometry (UPLC-IM-TOFMS) was utilized for the analysis of naphthenic acids (NAs) in fractions of pH-dependent sequential liquid-liquid extractions from oil sands process-affected water. Ion-mobility separation technique allowed the differentiation of OyS-NAs (2 ≤ y ≤ 4) from Ox-NAs (2 ≤ x ≤ 5) via drift time versus retention time separations. The results indicated that the addition of S atom to the O2-NA molecule led to a lower increase in the dissociation constant (pKa) compared to that caused by the addition of O atom...
October 2017: Chemosphere
https://www.readbyqxmd.com/read/28613826/microtrace-analysis-of-rare-earth-element-residues-in-femtogram-quantities-by-laser-desorption-and-laser-postionization-mass-spectrometry
#14
Zhibin Yin, Zhouyi Xu, Rong Liu, Wei Hang, Benli Huang
A newly developed laser desorption and laser postionization time-of-flight mass spectrometer (LD-LPI-TOFMS) for the direct microtrace determination of rare earth elements (REEs) in residues has been presented. Benefiting from spatially and temporally separated processes between desorption and ionization, LD-LPI-TOFMS plays a dual role in alleviating the barriers of deteriorating spectral resolution at high irradiance, serious matrix effects and elemental fractionation effects at low irradiance. Compared with the conventional laser desorption/ionization (LDI) method, this technique offers unambiguous full-elemental determination of 15 REEs with more uniform relative sensitivity coefficients (RSCs) ranging from 0...
June 28, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28608392/volatile-organic-compounds-analysis-by-pulsed-glow-discharge-time-of-flight-mass-spectrometry-as-a-structural-elucidation-tool
#15
M Bouza, J Fandino, N Bordel, R Pereiro, A Sanz-Medel
Pulsed glow discharge (PGD) coupled to time of flight mass spectrometry (TOFMS) has been investigated for volatile organic compounds (VOCs) identification and determination. Optimization of PGD operational conditions (chamber design, applied power, pressure and duty cycle) was performed using acetone and benzene as model compounds. During the different optimizations, molecular, fragment and elemental information were obtained when characteristic GD pulse regions were measured. An exploratory study for several VOCs (lineal hydrocarbons, oxygen-containing compounds and aromatic compounds) revealed the capability of the PGD to provide crucial information to elucidate structures (fragments), molecular ions or even proton affinity nature of the molecules; this last information is a consequence of the enriched proton environment generated along the afterglow region for the ionization chamber used...
June 12, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28601593/detection-of-over-100-selenium-metabolites-in-selenized-yeast-by-liquid-chromatography-electrospray-time-of-flight-mass-spectrometry
#16
Bienvenida Gilbert-López, Mihaly Dernovics, David Moreno-González, Antonio Molina-Díaz, Juan F García-Reyes
The characterization of the selenometabolome of Selenized(Se)-yeast, that is the fraction of water soluble low-molecular weight Se-metabolites produced in Se-yeast is of paramount interest to expand the knowledge on the composition of this food supplement. In this work, we have applied liquid chromatography electrospray time-of-flight mass spectrometry (LC-TOFMS) to search for Se-species from the low molecular weight range fraction of the selenized yeast used for food supplements. Prior to LC-TOFMS, sample treatment consisted of ultrasound assisted water extraction followed by size exclusion fractionation assisted with off-line inductively coupled plasma mass spectrometry detection of isotope (82)Se...
June 4, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28587778/advanced-method-optimization-for-volatile-aroma-profiling-of-beer-using-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry
#17
Pierre-Hugues Stefanuto, Katelynn A Perrault, Lena M Dubois, Benjamin L'Homme, Catherine Allen, Caitriona Loughnane, Nobuo Ochiai, Jean-François Focant
The complex mixture of volatile organic compounds (VOCs) present in the headspace of Trappist and craft beers was studied to illustrate the efficiency of thermal desorption (TD) comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) for highlighting subtle differences between highly complex mixtures of VOCs. Headspace solid-phase microextraction (HS-SPME), multiple (and classical) stir bar sorptive extraction (mSBSE), static headspace (SHS), and dynamic headspace (DHS) were compared for the extraction of a set of 21 representative flavor compounds of beer aroma...
June 1, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28582768/investigation-on-the-influence-of-time-of-day-on-benzene-metabolic-pharmacokinetics-by-direct-breath-analysis-in-mice
#18
Yuling Zhang, Wanyang Sun, Dewei Shang, Hao Gao, Zhen Zhou, Xue Li
Benzene, well known as a ubiquitous environmental pollutant, can lead to increasing risk of cancer, bone marrow failure as well as other serious diseases. Benzene has been classified as carcinogenic to humans with no recommended safe level of exposure. In this study, the influence of time-of-day on benzene metabolism has been tentatively explored in a mouse model based on direct real-time breath analysis by using membrane inlet single photon ionization time of flight mass spectrometry (MI-SPI-TOFMS). The exhaled breath of eight mice was monitored at a time resolution of less than 20 s after intraperitoneal (I...
October 2017: Chemosphere
https://www.readbyqxmd.com/read/28566235/investigation-of-storage-time-dependent-alterations-of-enantioselective-amino-acid-profiles-in-kimchi-using-liquid-chromatography-time-of-flight-mass-spectrometry
#19
Moyu Taniguchi, Yutaka Konya, Yosuke Nakano, Eiichiro Fukusaki
Although naturally abundant amino acids are represented mainly by l-enantiomers, fermented foods are known to contain various d-amino acids. Enantiospecific profiles of food products can vary due to fermentation by bacteria, and such alterations may contribute to changes in food properties that would not be dependent exclusively on l-amino acids. Therefore, more attention should be paid to the study of temporal alterations of d-amino acid profiles during fermentation process. However, there have been very few studies reporting time-dependent profiling of d-amino acids because enantioseparation of widely targeted d-amino acids is technically difficult...
May 26, 2017: Journal of Bioscience and Bioengineering
https://www.readbyqxmd.com/read/28544560/fatal-intoxication-by-5f-adb-and-diphenidine-detection-quantification-and-investigation-of-their-main-metabolic-pathways-in-human-by-lc-ms-ms-and-lc-q-tofms
#20
Maiko Kusano, Kei Zaitsua, Kentaro Taki, Kazuaki Hisatsune, Jun'ichi Nakajima, Takako Moriyasu, Tomomi Asano, Yumi Hayashi, Hitoshi Tsuchihashi, Akira Ishii
Despite the implementation of the new blanket scheduling system in 2013, new psychoactive substance (NPS) abuse remains a serious social concern in Japan. We present a fatal intoxication case involving 5F-ADB (methyl 2-[1-(5-fluoropentyl)-1H-indazole-3-carboxamido]-3,3-dimethylbutanoate) and diphenidine. Postmortem blood screening by liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOFMS) in the information dependent acquisition (IDA) mode only detected diphenidine. Further urinary screening using an in-house database containing new NPS and metabolites detected not only diphenidine but also possible 5F-ADB metabolites; subsequent targeted screening by LC/tandem mass spectrometry (LC/MS/MS) allowed for the detection of very low level of unchanged 5F-ADB in postmortem heart blood...
May 21, 2017: Drug Testing and Analysis
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