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https://www.readbyqxmd.com/read/28925692/occurrence-of-natural-mixed-halogenated-dibenzo-p-dioxins-specific-distribution-and-profiles-in-mussels-from-seto-inland-sea-japan
#1
Akitoshi Goto, Nguyen Minh Tue, Masayuki Someya, Tomohiko Isobe, Shin Takahashi, Shinsuke Tanabe, Tatsuya Kunisue
In addition to unintentional formation of polychlorinated (PCDD/Fs), polybrominated (PBDD/Fs) and mixed halogenated (PXDD/Fs) dibenzo-p-dioxins/dibenzofurans during industrial activities, recent studies have shown that several PBDD and PXDD congeners can be produced by marine algal species from the coastal environment. However, multiple exposure status of anthropogenic and naturally-derived dioxins in marine organisms remains unclear. The present study examined the occurrence, geographical distribution and potential sources of PCDD/Fs, PBDD/Fs and PXDD/Fs using mussels and brown algae collected in 2012 from Seto Inland Sea, Japan...
September 19, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28917730/direct-and-comprehensive-analysis-of-dyes-based-on-integrated-molecular-and-structural-information-via-laser-desorption-laser-postionization-mass-spectrometry
#2
Rong Liu, Zhibin Yin, Yixin Leng, Wei Hang, Benli Huang
Laser desorption laser postionization time-of-flight mass spectrometry (LDPI-TOFMS) was employed for direct analysis and determination of typical basic dyes. It was also used for the analysis and comprehensive understanding of complex materials such as blue ballpoint pen inks. Simultaneous emergences of fragmental and molecular information largely simplify and facilitate unambiguous identification of dyes via variable energy of 266nm postionization laser. More specifically, by optimizing postionization laser energy with the same energy of desorption laser, the structurally significant results show definite differences in the fragmentation patterns, which offer opportunities for discrimination of isomeric species with identical molecular weight...
January 1, 2018: Talanta
https://www.readbyqxmd.com/read/28911941/headspace-solid-phase-microextraction-coupled-to-comprehensive-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry-for-the-analysis-of-aerosol-from-tobacco-heating-product
#3
Benjamin Savareear, Radoslaw Lizak, Michał Brokl, Chris Wright, Chuan Liu, Jean-Francois Focant
A method involving headspace solid-phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS) was developed and optimised to elucidate the volatile composition of the particulate phase fraction of aerosol produced by tobacco heating products (THPs). Three SPME fiber types were studied in terms of extraction capacity and precision measurements. Divinylbenzene polydimethylsiloxane appeared as the most efficient coating for these measurements...
September 7, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28890492/a-quantitative-analysis-of-an-oil-component-in-an-emulsion-by-multiphoton-ionization-mass-spectrometry
#4
Hirofumi Fukaya, Tomohiro Uchimura
The first quantitative analysis of an oil component in an emulsion was achieved by multiphoton ionization time-of-flight mass spectrometry (MPI-TOFMS). An oil-in-water (O/W) emulsion was prepared. Styrene (0 - 5000 ng μL(-1)) and Triton X-100 were used as the oil phase and the disperser, respectively. Toluene was employed as an internal standard. We obtained a series of mass spectra, and then constructed the time profiles for styrene and toluene. As a result, we found several spikes from both time profiles when measuring emulsions with higher concentrations of styrene...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/28865386/response-of-rhizobium-to-cd-exposure-a-volatile-perspective
#5
Paulo Cardoso, Magda Santos, Rosa Freitas, Sílvia M Rocha, Etelvina Figueira
The volatile metabolome of Rhizobium sp. strain E20-8 exposed to three concentrations of cadmium (2.5, 5.0 and 7.5 μM) was screened using comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry (GC × GC-ToFMS), combined with headspace solid phase microextraction (HS-SPME). Cd exposure induced a global increase in the concentration of volatile organic compounds (VOCs) both intra and extracellularly. Peak areas of several linear alkanes, ketones, aldehydes, alcohols, terpenic and volatile sulfur compounds, and one ester (ethyl acetate), were especially increased when compared with the control condition (no Cd)...
August 30, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28843553/comparison-of-a-disposable-sorptive-sampler-with-thermal-desorption-in-a-gas-chromatographic-inlet-or-in-a-dedicated-thermal-desorber-to-conventional-stir-bar-sorptive-extraction-thermal-desorption-for-the-determination-of-micropollutants-in-water
#6
Madelien Wooding, Egmont R Rohwer, Yvette Naudé
The presence of micropollutants in the aquatic environment is a worldwide environmental concern. The diversity of micropollutants and the low concentration levels at which they may occur in the aquatic environment have greatly complicated the analysis and detection of these chemicals. Two sorptive extraction samplers and two thermal desorption methods for the detection of micropollutants in water were compared. A low-cost, disposable, in-house made sorptive extraction sampler was compared to SBSE using a commercial Twister sorptive sampler...
September 1, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28830588/chemotyping-of-new-hop-humulus-lupulus-l-genotypes-using-comprehensive-two-dimensional-gas-chromatography-with-quadrupole-accurate-mass-time-of-flight-mass-spectrometry
#7
DanDan Yan, Yong Foo Wong, Laura Tedone, Robert A Shellie, Philip J Marriott, Simon P Whittock, Anthony Koutoulis
Comprehensive two-dimensional gas chromatography with quadrupole accurate mass time-of-flight mass spectrometry (GC×GC-Q-TOFMS) is employed to profile Humulus lupulus L. (hop) essential oils. Comparison of characterised essential oils allows discrimination among chemotypes. Experimental and commercial hop genotypes displayed distinguishable chemotypic patterns among the volatile secondary metabolites making up their essential oils. In total, 210-306 unique compounds were detected (depending on specific genotype), with 99 of these compounds either positively or tentatively identified...
August 9, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28830000/fate-and-abundance-of-classical-and-heteroatomic-naphthenic-acid-species-after-advanced-oxidation-processes-insights-and-indicators-of-transformation-and-degradation
#8
Mohamed N A Meshref, Pamela Chelme-Ayala, Mohamed Gamal El-Din
The toxicological effects from all components in oil sands process-affected water (OSPW) are not known. Alternatively, monitoring the variations and abundance of different classes and compounds after treatments might be a useful approach in OSPW remediation. In this study, the variations in the compositions of classical and heteroatomic naphthenic acids (NAs) after treatment using advanced oxidation processes (AOPs), mainly ozone and peroxone, and two different mass spectrometry methods; ultra-performance liquid chromatography time-of-flight (UPLC-TOFMS) and Fourier transform ion cyclotron resonance (FTICR-MS), were examined...
August 4, 2017: Water Research
https://www.readbyqxmd.com/read/28814125/recreational-drug-use-at-a-major-music-festival-trend-analysis-of-anonymised-pooled-urine
#9
Lotte Christine Groth Hoegberg, Cecilie Christiansen, Jesper Soe, Rasmus Telving, Mette Findal Andreasen, Dan Staerk, Lona Louring Christrup, Kenneth Thermann Kongstad
OBJECTIVE: The spread of new psychoactive substances (NPS) has expanded rapidly in the last decade. The complexity of the pharmacological effects of NPS challenges the traditional treatment guidelines, and information of the emergence of new arrivals is valuable. Our knowledge on the actual range of recreational drugs used and NPS available in Denmark is limited as identification is possible only when consumers become patients in the healthcare system or through drug seizures. We aimed to detect classical recreational drugs and NPS in the urine of music festival attendees and evaluate if the use of NPS could have been predicted by comparing study data with drug seizure data from the previous year published by European and Danish health authorities...
August 17, 2017: Clinical Toxicology
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
#10
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
#11
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
#12
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
BACKGROUND & AIMS: Short telomeres and genetic telomerase defects are risk factors for some human liver diseases, ranging from non-alcoholic fatty liver disease and non-alcoholic steatohepatitis 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. Liver metabolic contents were analysed by CE-TOFMS and liver fat content was confirmed by confocal and electronic microscopy...
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
#13
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
#14
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
#15
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
#16
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 present since thousands of years in China. Clinical studies have shown that VN has the 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 of liver tissue metabolomics approach using on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOFMS)...
July 28, 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
#17
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
#18
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 analyzing a wide range of polarities encountered in the metabolome, 100%-wettable reversed-phase materials are frequently used to maximize 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...
September 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
#19
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
#20
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
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