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https://www.readbyqxmd.com/read/28535590/emission-of-volatile-organic-compounds-and-production-of-secondary-organic-aerosol-from-stir-frying-spices
#1
Tengyu Liu, Qianyun Liu, Zijun Li, Lei Huo, ManNin Chan, Xue Li, Zhen Zhou, Chak K Chan
Cooking is an important source of volatile organic compounds (VOCs) and a potential source of secondary organic aerosol (SOA) both indoors and outdoors. In this study, VOC emissions from heating corn oil and stir-frying spices (i.e. garlic, ginger, myrcia and zanthoxylum piperitum (Sichuan pepper)) were characterized using an on-line membrane inlet vacuum ultraviolet single-photon ionization time-of-flight mass spectrometer (VUV-SPI-TOFMS). VOC emissions from heating corn oil were dominated by aldehydes, which were enhanced by factors of one order of magnitude when stir-frying spices...
May 19, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28529831/source-identification-of-western-oregon-douglas-fir-wood-cores-using-mass-spectrometry-and-random-forest-classification
#2
Kristen Finch, Edgard Espinoza, F Andrew Jones, Richard Cronn
PREMISE OF THE STUDY: We investigated whether wood metabolite profiles from direct analysis in real time (time-of-flight) mass spectrometry (DART-TOFMS) could be used to determine the geographic origin of Douglas-fir wood cores originating from two regions in western Oregon, USA. METHODS: Three annual ring mass spectra were obtained from 188 adult Douglas-fir trees, and these were analyzed using random forest models to determine whether samples could be classified to geographic origin, growth year, or growth year and geographic origin...
May 2017: Applications in Plant Sciences
https://www.readbyqxmd.com/read/28514513/comprehensive-database-of-manufactured-gas-plant-tars-part-c-heterocyclic-and-hydroxylated-pahs
#3
Christopher Gallacher, Russell Thomas, Richard Lord, Robert M Kalin, Chris Taylor
RATIONALE: Coal tars are a mixture of organic and inorganic compounds and were by-products from the manufactured gas and coke making industries. The tar compositions varied depending on many factors such as the temperature of production and the type of retort used. For this reason a comprehensive database of the compounds found in different tar types is of value to understand both how their compositions differ and what potential chemical hazards are present. This study focuses on the heterocyclic and hydroxylated compounds present in a database produced from 16 different tars from 5 different production processes...
May 17, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28501191/tlc-uv-hyphenated-with-maldi-tofms-for-the-screening-of-invertase-substrates-in-plant-extracts
#4
Justine Ferey, David Da Silva, Pierre Lafite, Richard Daniellou, Benoît Maunit
In this study, thin-layer chromatography (TLC) hyphenated with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was developed for the screening of invertase substrates in complex matrices. BfrA, a specific β-D-fructofuranosidase from Leishmania major, was chosen as a model enzyme to screen biological activity in plant extracts due to its capacity to hydrolyze specific carbohydrates. TLC was considered to be a reliable technique for screening substrates (bioactive molecules) in plant extracts due to its quantitative capabilities whereas MALDI-TOFMS was particularly useful for rapid identification...
August 1, 2017: Talanta
https://www.readbyqxmd.com/read/28494122/comprehensive-database-of-manufactured-gas-plant-tars-part-b-aliphatic-and-aromatic-compounds
#5
Christopher Gallacher, Russell Thomas, Richard Lord, Robert M Kalin, Chris Taylor
RATIONALE: Coal tars are a mixture of organic and inorganic compounds and were produced as a by-product from the manufactured gas and coke making industries. The composition of the tar produced varied depending on many factors; these include the temperature of production and the type of retort used. As different production processes produce different tars, a comprehensive database of the compounds present within coal tars from different production processes is a valuable resource. Such a database would help to understand how their chemical properties differ and what hazards the compounds present within these tars might pose...
May 11, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28488792/comprehensive-database-of-manufactured-gas-plant-tars-part-a-database
#6
Christopher Gallacher, Russell Thomas, Richard Lord, Robert M Kalin, Chris Taylor
RATIONALE: Coal tars are a mixture of organic and inorganic compounds and were by-products from the manufactured gas and coke making industries. Different manufacturing processes have resulted in the production of distinctly different tar compositions. This study presents a comprehensive database of compounds produced using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS), analysing 16 tar samples produced by 5 distinct production processes...
May 10, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28473200/thermal-desorption-comprehensive-two-dimensional-gas-chromatography-coupled-to-variable-energy-electron-ionization-time-of-flight-mass-spectrometry-for-monitoring-subtle-changes-in-volatile-organic-compound-profiles-of-human-blood
#7
Lena M Dubois, Katelynn A Perrault, Pierre-Hugues Stefanuto, Stefan Koschinski, Matthew Edwards, Laura McGregor, Jean-François Focant
Blood is a matrix with high potential for forensic investigations and human rescue. Its volatile signature can be used in search exercises to locate injured or deceased individuals. Little is known, however, about the volatile organic compound (VOC) profile of blood, except that it is complex and varies while blood ages. In the present study, we used thermal desorption (TD) and comprehensive two-dimensional gas chromatography (GCxGC) coupled to variable-energy electron ionization time-of-flight mass spectrometry (TOFMS) to monitor VOC signatures of human blood...
April 13, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28452071/oxidative-stress-in-asthmatic-and-non-asthmatic-adolescent-swimmers-a-breathomics-approach
#8
Mariana Couto, Corália Barbosa, Diana Silva, Alisa Rudnitskaya, Luís Delgado, André Moreira, Sílvia M Rocha
We hypothesize that oxidative stress induced by trichloramine exposure during swimming could be related to etiopathogenesis of asthma among elite swimmers. AIM: To investigate the effect of a swimming training session on oxidative stress markers of asthmatic compared to non-asthmatic elite swimmers using exhaled breath (EB) metabolomics. METHODS: Elite swimmers annually screened in our department (n=27) were invited and those who agreed to participate (n=20, of which 9 with asthma) had EB collected (Tedlar(®) bags) before and after a swimming training session...
April 27, 2017: Pediatric Allergy and Immunology
https://www.readbyqxmd.com/read/28437060/high-throughput-and-quantitative-measurement-of-microbial-metabolome-by-gas-chromatography-mass-spectrometry-using-automated-alkyl-chloroformate-derivatization
#9
Linjing Zhao, Yan Ni, Mingming Su, Hongsen Li, Fangcong Dong, Wenlian Chen, Runmin Wei, Lulu Zhang, Seu Ping Guiraud, Francois-Pierre Martin, Cynthia Rajani, Guoxiang Xie, Wei Jia
The ability to identify and quantify small molecule metabolites derived from gut microbial-mammalian cometabolism is essential for the understanding of the distinct metabolic functions of the microbiome. To date, analytical protocols that quantitatively measure a complete panel of microbial metabolites in biological samples have not been established but are urgently needed by the microbiome research community. Here, we report an automated high-throughput quantitative method using a gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) platform to simultaneously measure over one hundred microbial metabolites in human serum, urine, feces, and Escherichia coli cell samples within 15 min per sample...
May 2, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28436032/application-of-maldi-tof-ms-for-estimating-the-postmortem-interval-in-rat-muscle-samples
#10
Chengzhi Li, Dong Ma, Kaifei Deng, Yijiu Chen, Ping Huang, Zhenyuan Wang
Estimating the postmortem interval (PMI) is very important in the forensic sciences. Although many approaches have been used for estimating the PMI, accurate PMI calculations are still difficult. In this study, four Sprague Dawley (SD) rats were sacrificed by suffocation, and muscle samples were collected by dissection at various time intervals (0, 48, 96, and 144 h) after death. All samples were probed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) to obtain molecular images and data for principal component analysis (PCA)...
April 23, 2017: Journal of Forensic Sciences
https://www.readbyqxmd.com/read/28424429/the-volatile-molecule-signature-of-four-mycobacteria-species
#11
Theodore Mellors, Christiaan Rees, Wendy Wieland-Alter, C Fordham von Reyn, Jane E Hill
Mycobacteria are the leading cause of death from infectious disease worldwide and limitations in current diagnostics are hampering control efforts. In recent years, the use of small volatile molecules as diagnostic biomarkers for mycobacteria has shown promise for use in the rapid analysis of in vitro cultures as well as ex vivo diagnosis using breath or sputum. In this study, 18 strains from four mycobacteria species (Mycobacterium avium, M. bovis BCG, M. intracellulare and M. xenopi) were analyzed for the first time using two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS)...
April 20, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28407955/influence-of-ripeness-and-maceration-of-the-grapes-on-levels-of-furan-and-carbonyl-compounds-in-wine-simultaneous-quantitative-determination-and-assessment-of-the-exposure-risk-to-these-compounds
#12
Laura Oliveira Lago, Karine Primieri Nicolli, Aline Biasoto Marques, Claudia Alcaraz Zini, Juliane Elisa Welke
The validated method based on the use of headspace solid phase microextraction (HS-SPME) coupled with the comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC/TOFMS) proved to be appropriate for this first simultaneous quantitative determination of six toxic compounds (formaldehyde, acetaldehyde, ethyl carbamate, furan, furfural and acrolein) found in wines. Acetaldehyde and acrolein coeluted with other wine compounds, which indicated that difficulties could arise if only one-dimensional gas chromatography was used for the determination of these compounds...
September 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28401661/chemical-discrimination-of-lubricant-marketing-types-using-direct-analysis-in-real-time-time-of-flight-mass-spectrometry
#13
Mark Maric, Lauren Harvey, Maren Tomcsak, Angelique Solano, Candice Bridge
RATIONALE: In comparison to other violent crimes, sexual assaults suffer from very low prosecution and conviction rates especially in the absence of DNA evidence. As a result, the forensic community needs to utilize other forms of trace contact evidence, like lubricant evidence, in order to provide a link between the victim and the assailant. METHODS: In this study, 90 personal bottled and condom lubricants from the three main marketing types, silicone-based, water-based and condoms, were characterized by direct analysis in real time time of flight mass spectrometry (DART-TOFMS)...
June 30, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28396122/evaluation-of-the-impact-of-gut-microbiota-on-uremic-solute-accumulation-by-a-ce-tofms-based-metabolomics-approach
#14
Eikan Mishima, Shinji Fukuda, Chikahisa Mukawa, Akinori Yuri, Yoshitomi Kanemitsu, Yotaro Matsumoto, Yasutoshi Akiyama, Noriko N Fukuda, Hiroki Tsukamoto, Kei Asaji, Hisato Shima, Koichi Kikuchi, Chitose Suzuki, Takehiro Suzuki, Yoshihisa Tomioka, Tomoyoshi Soga, Sadayoshi Ito, Takaaki Abe
Gut microbiota is involved in the metabolism of uremic solutes. However, the precise influence of microbiota to the retention of uremic solutes in CKD is obscure. To clarify this, we compared adenine-induced renal failure and control mice under germ-free or specific pathogen-free (SPF) conditions, examining the metabolite profiles of plasma, feces, and urine using a capillary electrophoresis time-of-flight mass spectrometry-based approach. Mice with renal failure under germ-free conditions demonstrated significant changes in plasma metabolites...
April 8, 2017: Kidney International
https://www.readbyqxmd.com/read/28389915/implementation-of-data-dependent-isotopologue-fragmentation-in-13-c-based-metabolic-flux-analysis
#15
Teresa Mairinger, Stephan Hann
A novel analytical approach based on liquid chromatography coupled to quadrupole time of flight mass spectrometry, employing data-dependent triggering for analysis of isotopologue and tandem mass isotopomer fractions of metabolites of the primary carbon metabolism was developed. The implemented QTOFMS method employs automated MS/MS triggering of higher abundant, biologically relevant isotopologues for generating positional information of the respective metabolite. Using this advanced isotopologue selective fragmentation approach enables the generation of significant tandem mass isotopomer data within a short cycle time without compromising sensitivity...
April 7, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28365075/determination-of-endocrine-disrupting-chemicals-and-antiretroviral-compounds-in-surface-water-a-disposable-sorptive-sampler-with-comprehensive-gas-chromatography-time-of-flight-mass-spectrometry-and-large-volume-injection-with-ultra-high-performance-liquid
#16
Madelien Wooding, Egmont R Rohwer, Yvette Naudé
Many rural dwellers and inhabitants of informal settlements in South Africa are without access to treated water and collect untreated water from rivers and dams for personal use. Endocrine disrupting chemicals (EDCs) have been detected in surface water and wildlife of South Africa. EDCs are often present in complex environmental matrices at ultra-trace levels complicating detection thereof. We report a simplified multi-residue approach for the detection and quantification of EDCs, emerging EDCs, and antiretroviral drugs in surface water...
May 5, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28343228/focal-brain-injury-associated-with-a-model-of-severe-hypoxic-ischemic-encephalopathy-in-nonhuman-primates
#17
Ryan M McAdams, Ronald J McPherson, Raj P Kapur, Sandra E Juul
Worldwide, hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal mortality and morbidity. To better understand the mechanisms contributing to brain injury and improve outcomes in neonates with HIE, better preclinical animal models that mimic the clinical situation following birth asphyxia in term newborns are needed. In an effort to achieve this goal, we modified our nonhuman primate model of HIE induced by in utero umbilical cord occlusion (UCO) to include postnatal hypoxic episodes, in order to simulate apneic events in human neonates with HIE...
March 25, 2017: Developmental Neuroscience
https://www.readbyqxmd.com/read/28340471/chemotaxonomic-studies-of-nine-paris-species-from-china-based-on-ultra-high-performance-liquid-chromatography-tandem-mass-spectrometry-and-fourier-transform-infrared-spectroscopy
#18
Yuanzhong Wang, Ehu Liu, Ping Li
Paris species, which contain steroid saponins, have been used as herb folk medicines in Asia. In the present study, a comprehensive strategy based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and Fourier transform infrared (FT-IR) spectroscopy was firstly proposed to evaluate the chemotaxonomic relationships of nine Paris species sampled from different geographical regions in China. Principle component analysis (PCA) based on FT-IR data revealed chemical similarities in term of the nine species and geographical regions, indicating the accumulation of metabolites affected by the combination of geographical factors and species...
June 5, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28340385/experimental-study-of-polyethylene-pyrolysis-and-combustion-over-hzsm-5-husy-and-mcm-41
#19
Que Huang, Changcheng Liu, Ruichao Wei, Jian Wang
The effects of temperatures, catalysts, and catalyst contents on polyethylene (PE) pyrolysis were investigated by using single-photon ionization time-of-flight mass spectrometry (SPI-TOFMS). The mass spectra of pyrolyzed PE and PE/catalysts from 300°C to 800°C illustrate that the pyrolysis reactions were apparently promoted and varied by introducing HZSM-5, HUSY, and MCM-41. As microporous catalysts, HZSM-5 and HUSY were found to accelerate the BTX formation at 400°C, which could not be observed for pure PE until 800°C...
March 14, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28328033/effects-of-molecular-weight-and-cationization-agent-on-the-sensitivity-of-bi-cluster-secondary-ion-mass-spectrometry
#20
Makiko Fujii, Rie Shishido, Takaya Satoh, Shigeru Suzuki, Jiro Matsuo
RATIONALE: Bi cluster secondary ion mass spectrometry (SIMS) is one of the most promising tools for precise analysis of synthetic polymers. However, the sensitivity in the high-mass region is still insufficient compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Accordingly, the effects of metal assistance (cationization agents) were investigated in this study. METHODS: To investigate the effects caused by varying the ionization agent, three different polyethylene glycol (PEG) samples were prepared, one with an Ag-deposited film, and two others mixed with Ag and Na, respectively...
July 30, 2016: Rapid Communications in Mass Spectrometry: RCM
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