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Volatile organic compound analysis

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https://www.readbyqxmd.com/read/28518086/ptr-tof-ms-coupled-with-an-automated-sampling-system-and-tailored-data-analysis-for-food-studies-bioprocess-monitoring-screening-and-nose-space-analysis
#1
Vittorio Capozzi, Sine Yener, Iuliia Khomenko, Brian Farneti, Luca Cappellin, Flavia Gasperi, Matteo Scampicchio, Franco Biasioli
Proton Transfer Reaction (PTR), combined with a Time-of-Flight (ToF) Mass Spectrometer (MS) is an analytical approach based on chemical ionization that belongs to the Direct-Injection Mass Spectrometric (DIMS) technologies. These techniques allow the rapid determination of volatile organic compounds (VOCs), assuring high sensitivity and accuracy. In general, PTR-MS requires neither sample preparation nor sample destruction, allowing real time and non-invasive analysis of samples. PTR-MS are exploited in many fields, from environmental and atmospheric chemistry to medical and biological sciences...
May 11, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28515887/bottom-up-and-top-down-effects-of-tree-species-diversity-on-leaf-insect-herbivory
#2
Bastien Castagneyrol, Damien Bonal, Maxime Damien, Hervé Jactel, Céline Meredieu, Evalyne W Muiruri, Luc Barbaro
The diversity of plant neighbors commonly results in direct, bottom-up effects on herbivore ability to locate their host, and in indirect effects on herbivores involving changes in plant traits and a top-down control by their enemies. Yet, the relative contribution of bottom-up and top-down forces remains poorly understood. We also lack knowledge on the effect of abiotic constraints such as summer drought on the strength and direction of these effects. We measured leaf damage on pedunculate oak (Quercus robur), alone or associated with birch, pine or both in a long-term tree diversity experiment (ORPHEE), where half of the plots were irrigated while the other half remained without irrigation and received only rainfall...
May 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28508885/first-characterisation-of-volatile-organic-compounds-emitted-by-banana-plants
#3
Chadi Berhal, Caroline De Clerck, Marie-Laure Fauconnier, Carolina Levicek, Antoine Boullis, Amine Kaddes, Haïssam M Jijakli, François Verheggen, Sébastien Massart
Banana (Musa sp.) ranks fourth in term of worldwide fruit production, and has economical and nutritional key values. The Cavendish cultivars correspond to more than 90% of the production of dessert banana while cooking cultivars are widely consumed locally around the banana belt production area. Many plants, if not all, produce Volatile Organic Compounds (VOCs) as a means of communication with their environment. Although flower and fruit VOCs have been studied for banana, the VOCs produced by the plant have never been identified despite their importance in plant health and development...
May 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28507202/determination-of-volatile-organic-compounds-exhaled-by-cell-lines-derived-from-hematological-malignancies
#4
Hongxia Tang, Yan Lu, Lulu Zhang, Zhonghui Wu, Xiaofang Hou, Hailong Xia
Background: The gas human exhaled contains many volatile organic compounds (VOCs), which is related to the health status of body. Analysis of VOCs has been proposed as a noninvasive diagnostic tool for certain cancers. Detailed research on the VOCs in gas exhaled by cell can characterize cell type specific metabolites and may be helpful to detect the cancer markers in clinical practice. Methods: Solid phase microextraction-gas chromatography-mass spectrometry was used to detect VOCs in the headspace of tissue culture flask in non-Hodgkin's lymphoma cell line JEKO and acute mononuclear leukemia cell line SHI-1, to elaborate the characteristic gaseous biomarkers of hematological malignancies...
May 15, 2017: Bioscience Reports
https://www.readbyqxmd.com/read/28500888/impact-of-furan-derivatives-and-phenolic-compounds-on-hydrogen-production-from-organic-fraction-of-municipal-solid-waste-using-co-culture-of-enterobacter-aerogenes-and-e-coli
#5
Preeti Sharma, Uma Melkania
In the present study, the effect of furan derivatives (furfural and 5-hydroxymethylfurfural) and phenolic compounds (vanillin and syringaldehyde) on hydrogen production from organic fraction of municipal solid waste (OFMSW) was investigated using co-culture of facultative anaerobes Enterobacter aerogenes and E. coli. The inhibitors were applied in the concentration ranges of 0.25, 0.5, 1, 2 and 5g/L each. Inhibition coefficients of phenolic compounds were higher than those of furan derivatives and vanillin exhibited maximum inhibition coefficients correspondingly lowest hydrogen yield among all inhibitors...
May 4, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28491071/exploring-blueberry-aroma-complexity-by-chromatographic-and-direct-injection-spectrometric-techniques
#6
Brian Farneti, Iuliia Khomenko, Marcella Grisenti, Matteo Ajelli, Emanuela Betta, Alberto Alarcon Algarra, Luca Cappellin, Eugenio Aprea, Flavia Gasperi, Franco Biasioli, Lara Giongo
Blueberry (Vaccinium spp.) fruit consumption has increased over the last 5 years, becoming the second most important soft fruit species after strawberry. Despite the possible economic and sensory impact, the blueberry volatile organic compound (VOC) composition has been poorly investigated. Thus, the great impact of the aroma on fruit marketability stimulates the need to step forward in the understanding of this quality trait. Beside the strong effect of ripening, blueberry aroma profile also varies due to the broad genetic differences among Vaccinium species that have been differently introgressed in modern commercial cultivars through breeding activity...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28490143/method-for-sampling-and-analysis-of-volatile-biomarkers-in-process-gas-from-aerobic-digestion-of-poultry-carcasses-using-time-weighted-average-spme-and-gc-ms
#7
Jacek A Koziel, Lam T Nguyen, Thomas D Glanville, Heekwon Ahn, Timothy S Frana, J Hans van Leeuwen
A passive sampling method, using retracted solid-phase microextraction (SPME) - gas chromatography-mass spectrometry and time-weighted averaging, was developed and validated for tracking marker volatile organic compounds (VOCs) emitted during aerobic digestion of biohazardous animal tissue. The retracted SPME configuration protects the fragile fiber from buffeting by the process gas stream, and it requires less equipment and is potentially more biosecure than conventional active sampling methods. VOC concentrations predicted via a model based on Fick's first law of diffusion were within 6...
October 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28484808/analysis-of-listeria-using-exogenous-volatile-organic-compound-metabolites-and-their-detection-by-static-headspace-multi-capillary-column-gas-chromatography-ion-mobility-spectrometry-shs-mcc-gc-ims
#8
Carl Taylor, Fraser Lough, Stephen P Stanforth, Edward C Schwalbe, Ian A Fowlis, John R Dean
Listeria monocytogenes is a Gram-positive bacterium and an opportunistic food-borne pathogen which poses significant risk to the immune-compromised and pregnant due to the increased likelihood of acquiring infection and potential transmission of infection to the unborn child. Conventional methods of analysis suffer from either long turn-around times or lack the ability to discriminate between Listeria spp. reliably. This paper investigates an alternative method of detecting Listeria spp. using two novel enzyme substrates that liberate exogenous volatile organic compounds in the presence of α-mannosidase and D-alanyl aminopeptidase...
May 8, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28481379/faster-health-deterioration-among-nail-technicians-occupationally-exposed-to-low-levels-of-volatile-organic-compounds
#9
Peter Grešner, Radosław Świercz, Wojciech Wąsowicz, Jolanta Gromadzińska
OBJECTIVES: The study has aimed at investigating the subjective assessment of an individual's health status and comparing the prevalence of selected work-related symptoms among nail technicians occupationally exposed to volatile organic compounds (VOCs) to the one among control subjects. Associations between occupational exposure to VOCs and the incidence of adverse health effects were also analyzed. MATERIAL AND METHODS: The study involved 145 female nail technicians and 152 control subjects...
May 8, 2017: International Journal of Occupational Medicine and Environmental Health
https://www.readbyqxmd.com/read/28468686/cucumber-mosaic-virus-and-its-2b-protein-alter-emission-of-host-volatile-organic-compounds-but-not-aphid-vector-settling-in-tobacco
#10
Trisna Tungadi, Simon C Groen, Alex M Murphy, Adrienne E Pate, Javaid Iqbal, Toby J A Bruce, Nik J Cunniffe, John P Carr
BACKGROUND: Aphids, including the generalist herbivore Myzus persicae, transmit cucumber mosaic virus (CMV). CMV (strain Fny) infection affects M. persicae feeding behavior and performance on tobacco (Nicotiana tabacum), Arabidopsis thaliana and cucurbits in varying ways. In Arabidopsis and cucurbits, CMV decreases host quality and inhibits prolonged feeding by aphids, which may enhance virus transmission rates. CMV-infected cucurbits also emit deceptive, aphid-attracting volatiles, which may favor virus acquisition...
May 3, 2017: Virology Journal
https://www.readbyqxmd.com/read/28464853/volatile-organic-compounds-associated-with-plasmodium-falciparum-infection-in-vitro
#11
Ricardo Correa, Lorena M Coronado, Anette C Garrido, Armando A Durant-Archibold, Carmenza Spadafora
BACKGROUND: In order to identify new ways to prevent transmission of vector-borne diseases such as malaria, efforts have been made to understand how insects are attracted to humans. Vector-host interaction studies have shown that several volatile compounds play an important role in attracting mosquitoes to human targets. A headspace solid-phase micro-extraction/gas chromatography-mass spectrometry (HSPME GC-MS) analysis of the volatile organic composition of extracellular vesicles (EVs) and supernatants of ultracentrifugation (SNUs) was carried out in Plasmodium falciparum-infected cultures with high and low parasitemias...
May 2, 2017: Parasites & Vectors
https://www.readbyqxmd.com/read/28462003/enhancing-anaerobic-digestion-of-poultry-blood-using-activated-carbon
#12
Maria José Cuetos, E Judith Martinez, Rubén Moreno, Rubén Gonzalez, Marta Otero, Xiomar Gomez
The potential of using anaerobic digestion for the treatment of poultry blood has been evaluated in batch assays at the laboratory scale and in a mesophilic semi-continuous reactor. The biodegradability test performed on residual poultry blood was carried out in spite of high inhibitory levels of acid intermediaries. The use of activated carbon as a way to prevent inhibitory conditions demonstrated the feasibility of attaining anaerobic digestion under extreme ammonium and acid conditions. Batch assays with higher carbon content presented higher methane production rates, although the difference in the final cumulative biogas production was not as sharp...
May 2017: Journal of Advanced Research
https://www.readbyqxmd.com/read/28456360/concentrically-packed-high-flow-air-sampler-for-parts-per-trillion-btex-compounds
#13
Xiaofeng Xie, H Dennis Tolley, Milton L Lee
Rapid determination of trace level (parts-per-trillion) volatile organic compounds cannot always be achieved with conventional analytical techniques. In this study, a device was developed to sample a large volume of air in a short time period. The basic design involves packing sorbent layers concentrically around an empty permeable tube. Single digit parts-per-trillion detection limits were reached in less than 25min with this sampling system using gas chromatography-mass spectrometry for analysis. The concentric packed trap can sample at high flow rates (>10L/min) because it has a large sampling surface cross-section and short combined sorbent bed...
April 26, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28440728/characterization-of-chemical-contaminants-generated-by-a-desktop-fused-deposition-modeling-3-dimensional-printer
#14
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/28439048/faecal-volatile-organic-compounds-analysis-using-field-asymmetric-ion-mobility-spectrometry-non-invasive-diagnostics-in-paediatric-inflammatory-bowel-disease
#15
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/28438317/a-novel-chromatographic-approach-to-distinguish-gram-positive-from-gram-negative-bacteria-using-exogenous-volatile-organic-compound-metabolites
#16
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/28426293/identifying-thermal-breakdown-products-of-thermoplastics
#17
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
#18
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/28422253/3d-printed-poly-vinylidene-fluoride-carbon-nanotube-composites-as-a-tunable-low-cost-chemical-vapour-sensing-platform
#19
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...
May 4, 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
#20
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
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