keyword
MENU ▼
Read by QxMD icon Read
search

Volatile organic compounds

keyword
https://www.readbyqxmd.com/read/28441613/atmospheric-degradation-of-2-chloroethyl-vinyl-ether-allyl-ether-and-allyl-ethyl-ether-kinetics-with-oh-radicals-and-uv-photochemistry
#1
M Antiñolo, A J Ocaña, J P Aranguren, S I Lane, J Albaladejo, E Jiménez
Unsaturated ethers are oxygenated volatile organic compounds (OVOCs) emitted by anthropogenic sources. Potential removal processes in the troposphere are initiated by hydroxyl (OH) radicals and photochemistry. In this work, we report for the first time the rate coefficients of the gas-phase reaction with OH radicals (kOH) of 2-chloroethyl vinyl ether (2ClEVE), allyl ether (AE), and allyl ethyl ether (AEE) as a function of temperature in the 263-358 K range, measured by the pulsed laser photolysis-laser induced fluorescence technique...
April 18, 2017: Chemosphere
https://www.readbyqxmd.com/read/28441489/a-comparison-of-gasoline-direct-injection-gdi-and-port-fuel-injection-pfi-vehicle-emissions-emission-certification-standards-cold-start-secondary-organic-aerosol-formation-potential-and-potential-climate-impacts
#2
Georges Saliba, Rawad Saleh, Yunliang Zhao, Albert A Presto, Andrew T Lambe, Bruce Frodin, Satya Sardar, Hector Maldonado, Christine Maddox, Andrew A May, Greg T Drozd, Allen H Goldstein, Lynn M Russell, Fabian P Hagen, Allen L Robinson
Recent increases in the Corporate Average Fuel Economy standards have led to widespread adoption of vehicles equipped with gasoline direct injection (GDI) engines. Changes in engine technologies can alter emissions. To quantify these effects, we measured gas- and particle-phase emissions from eighty-two light duty gasoline vehicles recruited from the California in-use fleet tested on a chassis dynamometer using the cold-start unified cycle. The fleet included 15 GDI vehicles, including 8 GDIs certified to the most stringent emissions standard, super-ultra-low-emission vehicles (SULEV)...
April 25, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28440728/characterization-of-chemical-contaminants-generated-by-a-desktop-fused-deposition-modeling-3-dimensional-printer
#3
Aleksandr B Stefaniak, Ryan F LeBouf, Jinghai Yi, Jason Ham, Timothy Nurkewicz, Diane E Schwegler-Berry, Bean T Chen, J Raymond Wells, Matthew G Duling, Robert B Lawrence, Stephen B Martin, Alyson R Johnson, M Abbas Virji
Printing devices are known to emit chemicals into the indoor atmosphere. Understanding factors that influence release of chemical contaminants from printers is necessary to develop effective exposure assessment and control strategies. In this study, a desktop fused deposition modeling (FDM) 3-D printer using acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) filaments and two monochrome laser printers were evaluated in a 0.5 m(3) chamber. During printing, chamber air was monitored for vapors using a real-time photoionization detector (results expressed as isobutylene equivalents) to measure total volatile organic compound (TVOC) concentrations, evacuated canisters to identify specific VOCs by off-line gas chromatography-mass spectrometry (GC-MS) analysis, and liquid bubblers to identify carbonyl compounds by GC-MS...
April 25, 2017: Journal of Occupational and Environmental Hygiene
https://www.readbyqxmd.com/read/28440225/observation-of-nonanoic-acid-and-aldehydes-in-exhaled-breath-of-patients-with-lung-cancer
#4
L Callol-Sanchez, M A Munoz-Lucas, O Gomez-Martin, J A Maldonado-Sanz, C Civera-Tejuca, C Gutierrez-Ortega, G Rodriguez-Trigo, J Jareno-Esteban
Lung cancer (LC) is the leading cause of cancer death in men and the second leading cause in women worldwide. The use of low-dose computed tomography in early diagnosis was shown to reduce mortality by 20% with a median follow-up time of 6.5 years. In order to increase profitability and reduce radiation risks and costs, exhaled biomarkers could serve to help establish narrower inclusion criteria. The aim of this study was to identify new, well-founded volatile organic compounds in exhaled breath which distinguish LC patients from chronic obstructive pulmonary disease (COPD) patients and healthy subjects...
April 25, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28440000/human-symptom-responses-to-bioeffluents-short-chain-carbonyls-acids-and-long-chain-carbonyls-in-a-simulated-aircraft-cabin-environment
#5
Clifford P Weisel, Nancy Fiedler, Charles J Weschler, Pamela Ohman-Strickland, Krishnan R Mohan, Kathy McNeil, David Space
Occupants of aircraft have reported an array of symptoms related to general discomfort and irritation. Volatile organic compounds (VOCs) have been suggested to contribute to the reported symptoms. VOCs are from products used, bioeffluents from people and ozone reaction products. Thirty-six healthy, young female subjects rated symptoms and environmental quality during an 8-hour exposure to groups of compounds often present in aircraft: 1) long chain carbonyls, 2) simulated bioeffluents, and 3) short chain carbonyls/organic acids...
April 25, 2017: Indoor Air
https://www.readbyqxmd.com/read/28439048/faecal-volatile-organic-compounds-analysis-using-field-asymmetric-ion-mobility-spectrometry-non-invasive-diagnostics-in-paediatric-inflammatory-bowel-disease
#6
Nora van Gaal, Rozanne Lakenman, James Covington, Richard Savage, Evelien de Groot, Marije Bomers, Marc Benninga, Chris Mulder, Nanne de Boer, Tim de Meij
Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), remains challenging to diagnose. Diagnostic work up carries a high burden, especially in paediatric patients, due to invasive endoscopic procedures. IBD is associated with alterations in intestinal microbiota composition. Faecal volatile organic compounds (VOCs) reflect gut microbiota composition. Aim of this study was to assess the diagnostic accuracy of faecal VOC profiling as non-invasive diagnostic biomarker for paediatric IBD...
April 25, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28439021/differences-between-measured-and-reported-volatile-organic-compound-emissions-from-oil-sands-facilities-in-alberta-canada
#7
Shao-Meng Li, Amy Leithead, Samar G Moussa, John Liggio, Michael D Moran, Daniel Wang, Katherine Hayden, Andrea Darlington, Mark Gordon, Ralf Staebler, Paul A Makar, Craig A Stroud, Robert McLaren, Peter S K Liu, Jason O'Brien, Richard L Mittermeier, Junhua Zhang, George Marson, Stewart G Cober, Mengistu Wolde, Jeremy J B Wentzell
Large-scale oil production from oil sands deposits in Alberta, Canada has raised concerns about environmental impacts, such as the magnitude of air pollution emissions. This paper reports compound emission rates (E) for 69-89 nonbiogenic volatile organic compounds (VOCs) for each of four surface mining facilities, determined with a top-down approach using aircraft measurements in the summer of 2013. The aggregate emission rate (aE) of the nonbiogenic VOCs ranged from 50 ± 14 to 70 ± 22 t/d depending on the facility...
April 24, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28438317/a-novel-chromatographic-approach-to-distinguish-gram-positive-from-gram-negative-bacteria-using-exogenous-volatile-organic-compound-metabolites
#8
Susana Ramírez-Guízar, Hannah Sykes, John D Perry, Edward C Schwalbe, Stephen P Stanforth, Ma Cristina I Perez-Perez, John R Dean
This paper utilized L-alanine aminopeptidase activity as a useful approach to distinguish between Gram-negative and Gram-positive bacteria. This was done using two enzyme substrates, specifically 2-amino-N-phenylpropanamide and 2-amino-N-(4-methylphenyl)propanamide which liberated the volatile compounds aniline and p-toluidine, respectively. Two complementary analytical techniques have been used to identify and quantify the VOCs, specifically static headspace multicapillary column gas chromatography ion mobility spectrometry (SHS-MCC-GC-IMS) and headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS)...
April 12, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28437609/source-and-biological-response-of-biochar-organic-compounds-released-into-water-relationships-with-bio-oil-composition-and-carbonization-degree
#9
Michele Ghidotti, Daniele Fabbri, Ondřej Mašek, Colin Logan Mackay, Marco Montalti, Andreas Hornung
Water-soluble organic compounds (WSOCs) were extracted from corn stalk biochar produced at increasing pyrolysis temperatures (350-650°C) and from the corresponding vapors, collected as bio-oil. WSOCs were characterized by gas chromatography (semi-volatile fraction), negative electron spray ionization high resolution mass spectrometry (hydrophilic fraction) and fluorescence spectroscopy. The pattern of semi-volatile WSOCs in bio-oil was dominated by aromatic products from lignocellulose, while in biochar was featured by saturated carboxylic acids from hemi/cellulose and lipids with concentrations decreased with decreasing H/C ratios...
April 24, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28436218/the-ptr3-a-novel-instrument-for-studying-the-lifecycle-of-reactive-organic-carbon-in-the-atmosphere
#10
Martin Breitenlechner, Lukas Fischer, Markus Hainer, Martin Heinritzi, Joachim Curtius, Armin Hansel
We have developed and characterized the novel PTR3, a Proton Transfer Reaction Time-of-Flight mass spectrometer (PTR-ToF) using a new gas inlet and an innovative reaction chamber design. The reaction chamber consists of a tripole operated with RF voltages generating an electric field only in radial direction. An elevated electrical field is necessary to reduce clustering of primary hydronium (H3O(+)) and product ions with water molecules present in the sample gas. The axial movement of the ions is achieved by the sample gas flow only...
April 24, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28432965/spatiotemporal-description-of-btex-volatile-organic-compounds-in-a-middle-eastern-megacity-tehran-study-of-exposure-prediction-for-environmental-health-research-tehran-sepehr
#11
Heresh Amini, Vahid Hosseini, Christian Schindler, Hossein Hassankhany, Masud Yunesian, Sarah B Henderson, Nino Künzli
The spatiotemporal variability of ambient volatile organic compounds (VOCs) in Tehran, Iran, is not well understood. Here we present the design, methods, and results of the Tehran Study of Exposure Prediction for Environmental Health Research (Tehran SEPEHR) on ambient concentrations of benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene (BTEX), and total BTEX. To date, this is the largest study of its kind in a low- and middle-income country and one of the largest globally. We measured BTEX concentrations at five reference sites and 174 distributed sites identified by a cluster analytic method...
April 19, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28429390/microporous-polyamide-membranes-for-molecular-sieving-of-nitrogen-from-volatile-organic-compounds
#12
Haoli Zhou, Fei Tao, Quan Liu, Chunxin Zong, Wenchao Yang, Xingzhong Cao, Wanqin Jin, Nanping Xu
Microporous polymer membranes continue to receive tremendous attention for energy-efficient gas separation processes owing to their high separation performances. A new network microporous polyamide membrane with good molecular-sieving performance for the separation of N2 from a volatile organic compound (VOC) mixture is described. Triple-substituted triptycene was used as the main monomer to form a fisherman's net-shaped polymer, which readily forms a composite membrane by solution casting. This membrane exhibited outstanding separation performance and good stability for the molecular-sieving separation of N2 over VOCs such as cyclohexane...
April 21, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28426293/identifying-thermal-breakdown-products-of-thermoplastics
#13
Marianne Guillemot, Benoît Oury, Sandrine Melin
Polymers processed to produce plastic articles are subjected to temperatures between 150°C and 450°C or more during overheated processing and breakdowns. Heat-based processing of this nature can lead to emission of volatile organic compounds (VOCs) into the thermoplastic processing shop. In this study, laboratory experiments, qualitative and quantitative emissions measurement in thermoplastic factories were carried out. The first step was to identify the compounds released depending on the thermoplastic nature, the temperature and the type of process...
April 20, 2017: Journal of Occupational and Environmental Hygiene
https://www.readbyqxmd.com/read/28423218/strain-specific-variation-in-plant-growth-promoting-volatile-organic-compound-production-by-five-different-pseudomonas-spp-as-confirmed-by-response-of-vigna-radiata-seedlings
#14
Jishma P, Nisma Hussain, Rakhi Chellappan, Romy Rajendran, Jyothis Mathew, Radhakrishnan E K
AIM: Analysis of blend of volatile organic compounds (VOCs) released by Pseudomonas spp. with growth promoting effect in Vigna radiata seedlings. METHODS AND RESULTS: Plant growth promoting activity of VOCs produced by five different Pseudomonas spp. was investigated by I-plate technique. VOCs produced by different organisms were extracted by various solvents (methanol, ethyl acetate, hexane and butanol) were identified by gas chromatography-mass spectrometric (GC-MS) analysis...
April 19, 2017: Journal of Applied Microbiology
https://www.readbyqxmd.com/read/28422943/the-effect-of-prenatal-tvoc-exposure-on-birth-and-infantile-weight-the-mothers-and-children-s-environmental-health-moceh-study
#15
Moonhee Chang, Hyesook Park, Mina Ha, Yun-Chul Hong, Youn-Hee Lim, Yangho Kim, Young Ju Kim, Dongheon Lee, Eun-Hee Ha
BACKGROUND: Volatile organic compounds (VOCs) might restrict prenatal and postnatal growth. However, the effect of prenatal VOCs exposure on postnatal growth has not been studied sufficiently. Thus we investigated the relationship between total volatile organic compounds (TVOC) exposure during pregnancy and postnatal growth. METHODS: A total of 383 pregnant participants were enrolled from 2006 to 2008. We investigated maternal characteristics using questionnaire...
April 19, 2017: Pediatric Research
https://www.readbyqxmd.com/read/28422253/3d-printed-poly-vinylidene-fluoride-carbon-nanotube-composites-as-a-tunable-low-cost-chemical-vapour-sensing-platform
#16
Z C Kennedy, J F Christ, K A Evans, B W Arey, L E Sweet, M G Warner, R L Erikson, C A Barrett
We report the production of flexible, highly-conductive poly(vinylidene fluoride) (PVDF) and multi-walled carbon nanotube (MWCNT) composites as filament feedstock for 3D printing. This account further describes, for the first time, fused deposition modelling (FDM) derived 3D-printed objects with chemiresistive properties in response to volatile organic compounds. The typically prohibitive thermal expansion and die swell characteristics of PVDF were minimized by the presence of MWCNTs in the composites enabling straightforward processing and printing...
April 19, 2017: Nanoscale
https://www.readbyqxmd.com/read/28421982/simultaneous-determination-of-volatile-organic-compounds-in-commercial-alcoholic-beverages-by-gas-chromatography-with-flame-ionization-detection
#17
Hyung Min Kim, Gun Yang, Jung Yoon Kim, Sang Jun Yoon, Byong-Kyu Shin, Jeongmi Lee, Jeong Hill Park, Sung Won Kwon
A simple and fast method was developed for the determination of volatile organic compounds in alcoholic beverages. Eleven volatile organic compounds (acetaldehyde, methanol, 2-propanol, <italic>tert</italic>-butanol, 1-propanol, ethyl acetate, 2-butanol, isobutanol, 1-butanol, 3-methyl-1butanol, and 2-methyl-1-butanol) in alcoholic beverages were analyzed with a simple direct-injection method using GC with flame ionization detection. These compounds should be monitored in the QC of production processes because they are detrimental to human health...
April 18, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28418289/volatile-organic-compounds-produced-by-a-soil-isolate-bacillus-subtilis-fa26-induce-adverse-ultra-structural-changes-to-the-cells-of-clavibacter-michiganensis-ssp-sepedonicus-the-causal-agent-of-bacterial-ring-rot-of-potato
#18
Faheem Uddin Rajer, Huijun Wu, Yongli Xie, Shanshan Xie, Waseem Raza, Hafiz Abdul Samad Tahir, Xuewen Gao
Rhizobacterial volatile organic compounds (VOCs) play an important role in the suppression of soil-borne phytopathogens. In this study, the VOCs produced by a soil-isolate, Bacillus subtilis FA26, were evaluated in vitro for their antibacterial activity against Clavibacter michiganensis ssp. sepedonicus (Cms), the causal agent of bacterial ring rot of potato. The VOCs emitted by FA26 inhibited the growth of Cms significantly compared with the control. Scanning and transmission electron microscopy analyses revealed distorted colony morphology and a wide range of abnormalities in Cms cells exposed to the VOCs of FA26...
April 18, 2017: Microbiology
https://www.readbyqxmd.com/read/28417171/resolution-optimized-headspace-gas-chromatography-ion-mobility-spectrometry-hs-gc-ims-for-non-targeted-olive-oil-profiling
#19
Natalie Gerhardt, Markus Birkenmeier, Daniel Sanders, Sascha Rohn, Philipp Weller
A prototype gas chromatography-ion mobility spectrometry (GC-IMS) system, hyphenating temperature-ramped headspace GC to a modified drift time IMS cell, was evaluated and compared to a conventional, isothermal capillary column (CC)-IMS system on the example of the geographical differentiation of extra virgin olive oils (EVOO) from Spain and Italy. It allows orthogonal, 2D separation of complex samples and individual detection of compounds in robust and compact benchtop systems. The information from the high-resolution 3D fingerprints of volatile organic compound (VOC) fractions of EVOO samples were extracted by specifically developed chemometric MATLAB® routines to differentiate between the different olive oil provenances...
April 17, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28416775/volatile-organic-compounds-in-gastrointestinal-stromal-tumour-tissue-originating-from-patient-derived-xenografts
#20
Renata Wawrzyniak, Agnieszka Woźniak, Yemarshet Gebreyohannes, Bartosz Dykcik, Patrick Schöffski, Michal Markuszewski
Gastrointestinal stromal tumours (GIST) are the most common mesenchymal neoplasms of the gastrointestinal tract, localized mainly in the stomach or small intestine. The metabolomic signature of GIST signature associated with various mutations in KIT gene remains undiscovered and unexplored. The main aim of this pilot study was to determine and compare metabolomic profiles in GIST xenograft models with different genetic background. Metabolomic profiling using gas chromatography coupled with mass spectrometry followed by both univariate and multivariate statistical analyses was applied to select metabolites which differentiate the GIST models studied...
April 18, 2017: Journal of Breath Research
keyword
keyword
43418
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"