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Volatile organic compound analysis

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https://www.readbyqxmd.com/read/29136906/comparison-of-common-components-analysis-with-principal-components-analysis-and-independent-components-analysis-application-to-spme-gc-ms-volatolomic-signatures
#1
Jihéne Bouhlel, Delphine Jouan-Rimbaud Bouveresse, Said Abouelkaram, Elisabeth Baéza, Catherine Jondreville, Angélique Travel, Jérémy Ratel, Erwan Engel, Douglas N Rutledge
The aim of this work is to compare a novel exploratory chemometrics method, Common Components Analysis (CCA), with Principal Components Analysis (PCA) and Independent Components Analysis (ICA). CCA consists in adapting the multi-block statistical method known as Common Components and Specific Weights Analysis (CCSWA or ComDim) by applying it to a single data matrix, with one variable per block. As an application, the three methods were applied to SPME-GC-MS volatolomic signatures of livers in an attempt to reveal volatile organic compounds (VOCs) markers of chicken exposure to different types of micropollutants...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29132208/organic-chemical-characterization-and-mass-balance-of-a-hydraulically-fractured-well-from-fracturing-fluid-to-produced-water-over-405-days
#2
James S Rosenblum, E Michael Thurman, Imma Ferrer, George R Aiken, Karl G Linden
A long-term field study (405 days) of a hydraulically fractured well from the Niobrara Formation in the Denver-Julesburg Basin was completed. Characterization of organic chemicals used in hydraulic fracturing and their changes through time, from the pre-injected fracturing fluid to the produced water, was conducted. The characterization consisted of a mass balance by dissolved organic carbon (DOC), volatile organic analysis by gas chromatography/mass spectrometry, and nonvolatile organic analysis by liquid chromatography/mass spectrometry...
November 14, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29131420/chromatographic-analysis-of-voc-patterns-in-exhaled-breath-from-smokers-and-nonsmokers
#3
Simonetta Capone, Maria Tufariello, Angiola Forleo, Valentina Longo, Lucia Giampietruzzi, Antonio Vincenzo Radogna, Flavio Casino, Pietro Siciliano
Cigarette smoking harms nearly every organ of the body and causes many diseases. The analysis of exhaled breath for exogenous and endogenous Volatile Organic Compounds (VOCs) can provide fundamental information on active smoking and insight into the health damage that smoke is creating. Various exhaled Volatile Organic Compounds (VOCs) have been reported as typical of smoking habit and recent tobacco consumption, but to date, no eligible biomarkers have been identified. Aiming to identify such potential biomarkers, in this pilot study we analysed the chemical patterns of exhaled breath from 26 volunteers divided in groups of nonsmokers and subgroups of smokers sampled at different periods of withdrawal from smoking...
November 13, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/29121563/benthic-invertebrate-exposure-and-chronic-toxicity-risk-analysis-for-cyclic-volatile-methylsiloxanes-comparison-of-hazard-quotient-and-probabilistic-risk-assessment-approaches
#4
Kent B Woodburn, Rita M Seston, Jaeshin Kim, David E Powell
This study utilized probabilistic risk assessment techniques to compare field sediment concentrations of the cyclic volatile methylsiloxane (cVMS) materials octamethylcyclotetrasiloxane (D4, CAS # 556-67-2), decamethylcyclopentasiloxane (D5, CAS # 541-02-6), and dodecamethylcyclohexasiloxane (D6, CAS # 540-97-6) to effect levels for these compounds determined in laboratory chronic toxicity tests with benthic organisms. The concentration data for D4/D5/D6 in sediment were individually sorted and the 95th centile concentrations determined in sediment on an organic carbon (OC) fugacity basis...
October 28, 2017: Chemosphere
https://www.readbyqxmd.com/read/29119317/prodigiosin-violacein-and-volatile-organic-compounds-produced-by-widespread-cutaneous-bacteria-of-amphibians-can-inhibit-two-batrachochytrium-fungal-pathogens
#5
Douglas C Woodhams, Brandon C LaBumbard, Kelly L Barnhart, Matthew H Becker, Molly C Bletz, Laura A Escobar, Sandra V Flechas, Megan E Forman, Anthony A Iannetta, Maureen D Joyce, Falitiana Rabemananjara, Brian Gratwicke, Miguel Vences, Kevin P C Minbiole
Symbiotic bacteria can produce secondary metabolites and volatile compounds that contribute to amphibian skin defense. Some of these symbionts have been used as probiotics to treat or prevent the emerging disease chytridiomycosis. We examined 20 amphibian cutaneous bacteria for the production of prodigiosin or violacein, brightly colored defense compounds that pigment the bacteria and have characteristic spectroscopic properties making them readily detectable, and evaluated the antifungal activity of these compounds...
November 9, 2017: Microbial Ecology
https://www.readbyqxmd.com/read/29112844/polycyclic-aromatic-hydrocarbons-in-house-dust-and-surface-soil-in-major-urban-regions-of-nepal-implication-on-source-apportionment-and-toxicological-effect
#6
Ishwar Chandra Yadav, Ningombam Linthoingambi Devi, Jun Li, Gan Zhang
Urban centers have turned to be the provincial store for resource consumptions and source releases of different types of semi-volatile organic compounds (SVOCs) including polycyclic aromatic hydrocarbons (PAHs), bringing about boundless environmental pollutions, among different issues. Human prosperity inside urban communities is unambiguously dependent on the status of urban soils and house dusts. However, environmental occurrence and sources of release of these SVOCs are challenging in Nepalese cities, as exceptionally very limited data are accessible...
November 4, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29111584/recent-applications-of-gc-with-high-resolution-ms
#7
REVIEW
Ivan Špánik, Andrea Machyňáková
Gas chromatography coupled to high-resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an accurate mass measurement. These features designate gas chromatography with high-resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi-volatile organic compounds. Gas chromatography with high-resolution mass spectrometry quantitative analyses were previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards...
November 7, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/29108583/metabolomics-analysis-of-human-sweat-collected-after-moderate-exercise
#8
M M Delgado-Povedano, M Calderón-Santiago, M D Luque de Castro, F Priego-Capote
Sweat is a promising biofluid scarcely used in clinical analysis despite its non-invasive sampling. A more frequent clinical use of sweat requires to know its whole composition, especially concerning to non-polar compounds, and the development of analytical strategies for its characterization. The aim of the present study was to compare different sample preparation strategies to maximize the detection of metabolites in sweat from humans collected after practicing moderate exercise. Special emphasis was put on non-polar compounds as they have received scant attention in previous studies dealing with this biofluid...
January 15, 2018: Talanta
https://www.readbyqxmd.com/read/29106611/mvoc-2-0-a-database-of-microbial-volatiles
#9
Marie C Lemfack, Bjoern-Oliver Gohlke, Serge M T Toguem, Saskia Preissner, Birgit Piechulla, Robert Preissner
Metabolic capabilities of microorganisms include the production of secondary metabolites (e.g. antibiotics). The analysis of microbial volatile organic compounds (mVOCs) is an emerging research field with huge impact on medical, agricultural and biotechnical applied and basic science. The mVOC database (v1) has grown with microbiome research and integrated species information with data on emitted volatiles. Here, we present the mVOC 2.0 database with about 2000 compounds from almost 1000 species and new features to work with the database...
November 2, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/29103645/emissions-of-volatile-sulfur-compounds-vscs-throughout-wastewater-biosolids-processing
#10
R M Fisher, N Le-Minh, J P Alvarez-Gaitan, S J Moore, R M Stuetz
Volatile sulfur compounds (VSCs) are important contributors to nuisance odours from the processing of wastewater sludge and biosolids. However, emission characteristics are difficult to predict as they vary between sites and are likely to be affected by biosolids processing configuration and operation. VSC emissions from biosolids throughout 6 wastewater treatment plants (WWTPs) in Sydney, Australia were examined in this study. H2S was the VSC found at the highest concentrations throughout the WWTPs, with concentrations ranging from 7 to 39,000μg/m(3)...
November 2, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29096120/detection-of-multiple-chemicals-based-on-external-cavity-quantum-cascade-laser-spectroscopy
#11
Juan Sun, Junya Ding, Ningwu Liu, Guangxiang Yang, Jingsong Li
A laser spectroscopy system based on a broadband tunable external cavity quantum cascade laser (ECQCL) and a mini quartz crystal tuning fork (QCTF) detector was developed for standoff detection of volatile organic compounds (VOCs). The self-established spectral analysis model based on multiple algorithms for quantitative and qualitative analysis of VOC components (i.e. ethanol and acetone) was detailedly investigated in both closed cell and open path configurations. A good agreement was obtained between the experimentally observed spectra and the standard reference spectra...
October 30, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/29091419/developing-a-vacuum-electrospray-source-to-implement-efficient-atmospheric-sampling-for-miniature-ion-trap-mass-spectrometer
#12
Quan Yu, Qian Zhang, Xinqiong Lu, Xiang Qian, Kai Ni, Xiaohao Wang
The performance of a miniature mass spectrometer in atmospheric analysis is closely related to the design of its sampling system. In this study, a simplified vacuum electrospray ionization (VESI) source was developed based on a combination of several techniques, including the discontinuous atmospheric pressure interface, direct capillary sampling, and pneumatic-assisted electrospray. Pulsed air was used as a vital factor to facilitate the operation of electrospray ionization in the vacuum chamber. This VESI device can be used as an efficient atmospheric sampling interface when coupled with a miniature rectilinear ion trap (RIT) mass spectrometer...
November 14, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29089106/development-of-carbotrap-b-packed-needle-trap-device-for-determination-of-volatile-organic-compounds-in-air
#13
Ali Poormohammadi, Abdulrahman Bahrami, Maryam Farhadian, Farshid Ghorbani Shahna, Alireza Ghiasvand
Carbotrap B as a highly pure surface sorbent with excellent adsorption/desorption properties was packed into a stainless steel needle to develop a new needle trap device (NTD). The performance of the prepared NTD was investigated for sampling, pre-concentration and injection of benzene, toluene, ethyl benzene, o-xylene, and p-xylene (BTEX) into the column of gas chromatography-mass spectrometry (GC-MS) device. Response surface methodology (RSM) with central composite design (CCD) was also employed in two separate consecutive steps to optimize the sampling and device parameters...
October 26, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29082668/breathomics-from-exhaled-volatile-organic-compounds-in-pediatric-asthma
#14
REVIEW
Anne H Neerincx, Susanne J H Vijverberg, Lieuwe D J Bos, Paul Brinkman, Marc P van der Schee, Rianne de Vries, Peter J Sterk, Anke-Hilse Maitland-van der Zee
Asthma is the most common chronic disease in children, and is characterized by airway inflammation, bronchial hyperresponsiveness, and airflow obstruction. Asthma diagnosis, phenotyping, and monitoring are still challenging with currently available methods, such as spirometry, FE NO or sputum analysis. The analysis of volatile organic compounds (VOCs) in exhaled breath could be an interesting non-invasive approach, but has not yet reached clinical practice. This review describes the current status of breath analysis in the diagnosis and monitoring of pediatric asthma...
October 30, 2017: Pediatric Pulmonology
https://www.readbyqxmd.com/read/29072096/salvia-broussonetii-benth-aroma-profile-and-micromorphological-analysis
#15
Basma Najar, Luisa Pistelli, Claudio Cervelli, Gelsomina Fico, Claudia Giuliani
The volatile profiles (VOC) and the essential oil (EO) composition from the aerial parts of Salvia broussonetii were analysed. Sesquiterpene hydrocarbons dominate the VOCs from leaves (95.7%) and flowers (67.6%), followed by monoterpene hydrocarbons (2.6 and 29.7%, respectively). The main common compounds are germacrene D, β-bourbonene, α-pinene, α-copaene and α-gurjunene, even if with divergent relative abundances. In the leaf EOs the sesquiterpenes prevail, even if not overwhelmingly (about 50.0%), followed by monoterpenes (23...
October 26, 2017: Natural Product Research
https://www.readbyqxmd.com/read/29070093/properties-and-aromatic-profile-of-dry-fermented-sausages-produced-from-kr%C3%A5-kopolje-pigs-reared-under-organic-and-conventional-rearing-regime
#16
M Škrlep, M Čandek-Potokar, U Tomažin, N Batorek Lukač, M Flores
Krškopolje pig, the only Slovenian autochtonous breed is still relatively untapped, with almost no information available on the effect of rearing conditions or its aptitude for processing and meat product quality. In the present study, dry-fermented sausages were produced from Krškopolje pigs that were fed similar diets (with regard to ingredients, energy and protein content) but reared in either conventional (CON) or organic conditions (ECO). Sausage weight losses at the end of processing were recorded and their final pH, chemical composition (moisture, fat and protein content, proteolysis index, fat and protein oxidation, fatty acid and free fatty acid profile) were determined in addition to measurements of instrumental texture, sensory evaluation and volatile profile analysis...
October 26, 2017: Animal: An International Journal of Animal Bioscience
https://www.readbyqxmd.com/read/29068318/advances-in-chemical-sensing-technologies-for-vocs-in-breath-for-security-threat-assessment-illicit-drug-detection-and-human-trafficking-activity
#17
Stamatios Giannoukos, Agapios Agapiou, S Taylor
On-site chemical sensing of compounds associated with security and terrorist attacks is of worldwide interest. Other related bio-monitoring topics include identification of individuals posing a threat from illicit drugs, explosive manufacturing, as well as searching for victims of human trafficking and collapsed buildings. The current status of field analytical technologies is directed towards the detection and identification of vapours and volatile organic compounds (VOCs). Some VOCs are associated with exhaled breath; where research is moving from individual breath testing (volatilome) to cell breath (microbiome) and most recently to crowd breath metabolites (exposome)...
October 25, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/29064449/molecular-affinity-of-mabolo-extracts-to-an-octopamine-receptor-of-a-fruit-fly
#18
Francoise Neil D Dacanay, Ma Carmina Joyce A Ladra, Hiyas A Junio, Ricky B Nellas
Essential oils extracted from plants are composed of volatile organic compounds that can affect insect behavior. Identifying the active components of the essential oils to their biochemical target is necessary to design novel biopesticides. In this study, essential oils extracted from Diospyros discolor (Willd.) were analyzed using gas chromatography mass spectroscopy (GC-MS) to create an untargeted metabolite profile. Subsequently, a conformational ensemble of the Drosophila melanogaster octopamine receptor in mushroom bodies (OAMB) was created from a molecular dynamics simulation to resemble a flexible receptor for docking studies...
October 24, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29061475/characterization-of-organic-aromatic-compounds-in-soils-affected-by-an-uncontrolled-tire-landfill-fire-through-the-use-of-comprehensive-two-dimensional-gas-chromatography-time-of-flight-mass-spectrometry
#19
J Escobar-Arnanz, S Mekni, G Blanco, E Eljarrat, D Barceló, L Ramos
Discarded vehicle tires have become an increasing concern worldwide due to the enormous amount of wastes generated and the increasing evidence of health problems associated to their disposal and accidental combustion. Previous studies conducted involving either simulated or open uncontrolled tire fires have identified aromatics belonging to two main classes, volatile organic compounds and polycyclic aromatic compounds (PAHs), as the most relevant chemicals generated in these burning processes. As a consequence, and due to their recognized toxicity, most studies reported up to now have mainly focused on these two categories of compounds being information concerning the possible occurrence of other aromatic classes rather limited...
October 20, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29060925/breath-based-volatile-organic-compounds-in-the-detection-of-breast-lung-and-colorectal-cancers-a-systematic-review
#20
Ingrid Oakley-Girvan, Sharon Watkins Davis
BACKGROUND: Detecting volatile organic compounds (VOCs) could provide a rapid, noninvasive, and inexpensive screening tool for detecting cancer. OBJECTIVE: In this systematic review, we identified specific exhaled breath VOCs correlated with lung, colorectal, and breast cancer. METHODS: We identified relevant studies published in 2015 and 2016 by searching Pubmed and Web of Science. The protocol for this systematic review was registered in PROSPERO and the PRISMA guidelines were used in reporting...
October 8, 2017: Cancer Biomarkers: Section A of Disease Markers
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