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volatile organic compound

Joseph O Okeme, Eva M Webster, J Mark Parnis, Miriam L Diamond
Partition coefficients between polyurethane foam (PUF) and air (KPUF-Air) are important when using PUF as a passive air sampler for semi-volatile organic compounds (SVOCs) and when considering the fate of SVOCs indoors where PUF is a common material. Here, KPUF-Air for selected SVOCs was estimated using published methods, since measured data are unavailable for most of these compounds. Estimates of KPUF-Air were within one order of magnitude for SVOCs having values of log octanol-air partition coefficient (KOA) of 5, but differed by nearly three orders of magnitude for SVOCs with log KOA of 12...
October 23, 2016: Chemosphere
Yu-Chun Wang, Chitsan Lin, Yu-Kai Lin, Ya-Fen Wang, Wei-Huang Weng, Yi-Ming Kuo
This study evaluates the effects of a sampling strategy that includes the sampling season, time period, ambient environment, and location on determining the concentrations and species of ambient volatile organic compounds (VOCs) that may affect children in primary schools. Air samples were collected from playgrounds in primary schools, with four sites near an oil refinery plant in Taoyuan and two sites in Zhongli (one site near a bus terminal and the other site in a suburban area) in Taiwan. The samples were obtained on eight occasions from August 2010 to June 2011...
October 26, 2016: Environmental Science. Processes & Impacts
José Javier Jareño-Esteban, M Ángeles Muñoz-Lucas, Óscar Gómez-Martín, Sergio Utrilla-Trigo, Carlos Gutiérrez-Ortega, Antonio Aguilar-Ros, Luis Collado-Yurrita, Luis Miguel Callol-Sánchez
INTRODUCTION: A major risk factor for chronic obstructive pulmonary disease (COPD) is tobacco smoke, which generates oxidative stress in airways, resulting in the production of volatile organic compounds (VOC). The purpose of this study was to identify VOCs in exhaled breath and to determine their possible use as disease biomarkers. METHOD: Exhaled breath from 100 healthy volunteers, divided into 3groups (never smokers, former smokers and active smokers) and exhaled breath from 57 COPD patients were analyzed...
October 22, 2016: Archivos de Bronconeumología
Lanling Chu, Siwei Deng, Renshan Zhao, Jianjun Deng, Xuejun Kang
The objective of this study was to compare the adsorption/desorption of target compounds on homemade electrospun nanofibers, polystyrene (PS) nanofibers, acrylic resin (AR) nanofibers and PS-AR composite nanofibers with Tenax TA. Ten volatile organic compounds (VOCs) were analyzed by preconcentration onto different sorbents followed by desorption (thermal and solvent orderly) and analysis by capillary gas chromatography. In comparison to Tenax TA, the electrospun nanofibers displayed a significant advantage in desorption efficiency and adsorption selectivity...
2016: PloS One
Wen-Long Li, Wan-Li Ma, Hongliang Jia, Wenjun Hong, Hyo-Bang Moon, Haruhiko Nakata, Nguyen Hung Minh, Ravindra Kumar Sinha, Kai Hsien Chi, Kurunthachalam Kannan, Ed Sverko, Yi-Fan Li
A total of 23 PBDE congeners were measured in soil samples collected in areas with no known point source (urban/rural/background sites, U/R/B sites) and in contaminated areas (brominated flame retardants (BFRs) related industrial and e-waste recycling sites) across five Asian countries. The highest PBDE concentrations were found in BFRs related industrial and e-waste recycling sites. The concentrations of PBDEs in U/R/B sites followed the order of: urban > rural > background sites. Total PBDE concentrations were dominated by BDE-209, while BDE-17, -85, -138, -191, -204 and -205 were the least abundant compounds...
October 24, 2016: Environmental Science & Technology
J Rodrigo Magana, Yury V Kolen'ko, Francis Leonard Deepak, Conxita Solans, Rekha Goswami Shrestha, Jonathan P Hill, Katsuhiko Ariga, Lok Kumar Shrestha, Carlos Rodriguez-Abreu
Carbon nanofibers (CNFs) with high surface area (820 m2/g) have been successfully prepared by a nanocasting approach using silica nanofibers obtained from chromonic liquid crystals as a template. CNFs with randomly oriented graphitic layers show outstanding electrochemical supercapacitance performance exhibiting a specific capacitance of 327 F/g at a scan rate of 5 mV/s with long life cycling capability. Approximately 95% capacitance retention is observed after 1000 charge-discharge cycles. Furthermore, about 80% of capacitance is retained at higher scan rates (up to 500 mV/s) and current densities (from 1 to 10 A/g)...
October 24, 2016: ACS Applied Materials & Interfaces
Fabrice Gritti, Michael Fogwill, Martin Gilar, Joseph A Jarrell
The rapid and complete baseline separation of both volatile (C5 to C16 alkanes in gasoline or terpenes in plant extracts) and non-volatile (>C20 alkanes) organic compounds was achieved by combining (1) low-density fluid chromatography (LDFC) using carbon dioxide at elevated temperature (>90°C) and low pressure (1500psi) designed to increase the retention of the most volatile compounds and (2) high-vacuum technology (<10(-4)Torr) in order to preserve the maximum efficiency of short analytical columns (3...
October 18, 2016: Journal of Chromatography. A
Kyle D Custard, Kerri A Pratt, Siyuan Wang, Paul B Shepson
During springtime, unique halogen chemistry involving chlorine and bromine atoms controls the prevalence of volatile organic compounds, ozone, and mercury in the Arctic lower troposphere. In situ measurements of the chlorine monoxide radical (ClO) and its precursor Cl2, along with BrO and Br2, were conducted using chemical ionization mass spectrometry (CIMS) during the BRomine, Ozone, and Mercury EXperiment (BROMEX) near Barrow, Alaska in March 2012. To our knowledge, these data represent the first ClO measurements made using CIMS...
October 21, 2016: Environmental Science & Technology
Dong Bok Jeon, Young Shin Hong, Ga Hyun Lee, Yu Min Park, Cheong Mi Lee, Eun Yeong Nho, Ji Yeon Choi, Nargis Jamila, Naeem Khan, Kyong Su Kim
Tea contains characteristic volatile organic compounds, polyphenols, caffeine and catechins, and is therefore among the most widely consumed beverages all over the world. In this study, fresh Jukro tea leaves collected from Damyang-gun (Jeollanam-do) at 40, 60 and 90day growth stages, were semi-fermented. The volatile organic compounds (VOCs) were extracted by simultaneous distillation-solvent extraction (SDE) and analyzed by gas chromatography/mass spectrometry (GC/MS). Catechins, caffeine and theanine were analyzed by high performance liquid chromatography (HPLC)...
March 15, 2017: Food Chemistry
Jing Li, Tengfei Fan, Yong Xu, Xuemin Wu
Emulsifiers for pesticide microemulsions contain a part of volatile organic compounds (VOCs), and ionic liquids (ILs) are becoming potential substitutes. In order to apply ILs in pesticide microemulsions, the study of interaction between ILs and surfactants is necessary. Therefore, the surface properties and aggregation of anionic surfactant sodium dodecyl sulfate (SDS) in ILs, including N-hexyl-N-methylmorpholinyl bromide ([C6mm][Br]), N-hexyl-N-methylpiperidyl bromide ([C6mp][Br]), N-hexyl-N-methylpyrrolidyl bromide ([C6mpyr][Br]), N-octyl-N-methylpyrrolidyl bromide ([C8mpyr][Br]), N-dodecyl-N-methylpyrrolidyl bromide ([C12mpyr][Br]) and N-hexadecyl-N-methylpyrrolidyl bromide ([C16mpyr][Br]), were investigated in terms of surface tension, conductivity, dynamic light scattering (DLS), viscosity, fluorescence, pseudo-ternary phase diagram and (1)H NMR measurements...
October 19, 2016: Physical Chemistry Chemical Physics: PCCP
Laura Capelli, Gianluigi Taverna, Alessia Bellini, Lidia Eusebio, Niccolò Buffi, Massimo Lazzeri, Giorgio Guazzoni, Giorgio Bozzini, Mauro Seveso, Alberto Mandressi, Lorenzo Tidu, Fabio Grizzi, Paolo Sardella, Giuseppe Latorre, Rodolfo Hurle, Giovanni Lughezzani, Paolo Casale, Sara Meregali, Selena Sironi
The electronic nose is able to provide useful information through the analysis of the volatile organic compounds in body fluids, such as exhaled breath, urine and blood. This paper focuses on the review of electronic nose studies and applications in the specific field of medical diagnostics based on the analysis of the gaseous headspace of human urine, in order to provide a broad overview of the state of the art and thus enhance future developments in this field. The research in this field is rather recent and still in progress, and there are several aspects that need to be investigated more into depth, not only to develop and improve specific electronic noses for different diseases, but also with the aim to discover and analyse the connections between specific diseases and the body fluids odour...
October 14, 2016: Sensors
Marika Rai, David Spratt, Paola R Gomez-Pereira, Jay Patel, Sean P Nair
Oral malodour is a common condition which affects a large proportion of the population, resulting in social, emotional and psychological stress. Certain oral bacteria form a coating called a biofilm on the tongue dorsum and degrade organic compounds releasing volatile sulfur compounds that are malodourous. Current chemical treatments for oral malodour such as mouthwashes containing chlorhexidine or essential oils, are not sufficiently effective at reducing the bacterial load on the tongue. One potential alternative to current chemical treatments for oral malodour is the use of light activated antimicrobial agents (LAAAs), which display no toxicity or antimicrobial activity in the dark, but when exposed to light of a specific wavelength produce reactive oxygen species which induce damage to target cells in a process known as photodynamic inactivation...
October 18, 2016: Journal of Breath Research
Sang Pil Hong, Eun Joo Lee, Young Ho Kim, Dong Uk Ahn
This study was conducted to evaluate the effect of fermentation temperature on the volatile composition in Kimchi. Kimchi was fermented at 2 temperature conditions (4 and 20 °C). Volatile compounds of Kimchi samples were analyzed during the fermentation periods using the dynamic headspace gas chromatography-mass spectrometry method. The optimum ripening time for the Kimchi fermented at 4 °C was 35 d, and that of 20 °C was 2 d. The pH at the optimum ripening time was 4.97 and 4.41, and the titratable acidity was 0...
October 17, 2016: Journal of Food Science
Anandram Venkatasubramanian, Vincent T K Sauer, Swapan K Roy, Mike Xia, David S Wishart, Wayne K Hiebert
Micro-Gas Chromatography (GC) is promising for portable chemical analysis. We demonstrate a nano-optomechanical system (NOMS) as an ultrasensitive mass detector in gas chromatography. Bare, native oxide, silicon surfaces are sensitive enough to monitor volatile organic compounds at ppm levels, while simultaneously demonstrating chemical selectivity. The NOMS is able to sense GC peaks from derivatized metabolites at physiological concentrations. This is an important milestone for small-molecule quantitation assays in next generation metabolite analyses for applications such as disease diagnosis and personalized medicine...
October 17, 2016: Nano Letters
Guozhu Zhao, Guohua Yin, Arati A Inamdar, Jing Luo, Ning Zhang, Ill Yang, Brian Buckley, Joan W Bennett
Super Storm Sandy provided an opportunity to study filamentous fungi (molds) associated with winter storm damage. We collected 36 morphologically distinct fungal isolates from flooded buildings. By combining traditional morphological and cultural characters with an analysis of ITS sequences (the fungal DNA barcode), we identified 24 fungal species that belong to 8 genera: Penicillium (12 species), Fusarium (4 species), Aspergillus (3 species), Trichoderma (2 species), and one species each of Metarhizium, Mucor, Pestalotiopsis, and Umbelopsis...
October 17, 2016: Indoor Air
Kenion H Blakeman, Craig A Cavanaugh, William M Gilliland, J Michael Ramsey
RATIONALE: There are many chemical measurement scenarios that would benefit from hand portable mass spectrometry tools including forensics, environmental monitoring, and safety and security. High pressure mass spectrometry (HPMS) facilitates miniaturization by significantly reducing vacuum system requirements. Previous work demonstrated HPMS using helium buffer gas, but HPMS conducted using ambient air would further reduce the size and weight of a portable instrument while also reducing logistical demands by eliminating the need for a helium supply...
October 17, 2016: Rapid Communications in Mass Spectrometry: RCM
Charlie E Kivi, Datong Song
A new metal-organic framework (1) constructed from 4-(4-(3,5-dimethyl-1H-pyrazol-4-yl)phenyl)pyridine (HL) and CuBr shows potential as a luminescent sensor for volatile organic compounds.
October 17, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Jin-Lian Chen, Shi-Zhong Sun, Cui-Ping Miao, Kai Wu, You-Wei Chen, Li-Hua Xu, Hui-Lin Guan, Li-Xing Zhao
BACKGROUND: Biocontrol agents are regarded as promising and environmental friendly approaches as agrochemicals for phytodiseases that cause serious environmental and health problems. Trichoderma species have been widely used in suppression of soil-borne pathogens. In this study, an endophytic fungus, Trichoderma gamsii YIM PH30019, from healthy Panax notoginseng root was investigated for its biocontrol potential. METHODS: In vitro detached healthy roots, and pot and field experiments were used to investigate the pathogenicity and biocontrol efficacy of T...
October 2016: Journal of Ginseng Research
Guiqian Tang, Na Chao, Yuesi Wang, Jiashan Chen
Vehicular emissions in China in 2006 and 2010 were calculated at a high spatial resolution based on the data released by the National Bureau of Statistics, by taking the emission standards into consideration. China's vehicular emissions of carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), ammonia (NH3), fine particulate matters (PM2.5), inhalable particulate matters (PM10), black carbon (BC), and organic carbon (OC) were 30,113.9, 4593.7, 6838.0, 20.9, 400.2, 430.5, 285.6, and 105...
October 2016: Journal of Environmental Sciences (China)
Qinghuan Xu, Lin Yang, Wangting Yang, Yan Bai, Ping Hou, Jingxian Zhao, Lv Zhou, Zhaojiang Zuo
Eutrophication promotes massive growth of cyanobacteria and algal blooms, which can poison other algae and reduce biodiversity. To investigate the differences in multiple nitrogen (N) sources in eutrophicated water on the emission of volatile organic compounds (VOCs) from cyanobacteria, and their toxic effects on other algal growth, we analyzed VOCs emitted from Microcystis flos-aquae with different types and concentrations of nitrogen, and determined the effects under Normal-N and Non-N conditions on Chlorella vulgaris...
October 11, 2016: Ecotoxicology and Environmental Safety
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