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Volatile organic compound analysis

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https://www.readbyqxmd.com/read/28925377/applied-upper-airway-resistance-instantly-affects-breath-components-a-unique-insight-into-pulmonary-medicine
#1
Pritam Sukul, Jochen Schubert, Svend Kamysek, Phillip Trefz, Wolfram Miekisch
Respiratory parameters such as flow or rate have complex effects onto exhalation of volatile substances and can hamper clinical interpretation of breath biomarkers. We investigated effects of progressively applied upper-airway resistances onto exhalation of volatile organic compounds (VOCs) in healthy humans. We performed real-time mass-spectrometric determination of breath volatiles in 50 subjects with parallel non-invasive hemodynamic monitoring, breath-resolved spirometry and capnometry during controlled tidal breathing (12 breaths/min)...
September 19, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28922624/quantification-of-voc-emissions-from-paint-spraying-on-a-construction-site-using-solid-phase-microextraction-devices
#2
Wen-Hsi Cheng, Hsiao-Lin Huang, Kang-Shin Chen, Yu-Jen Chang
The objective of this study was to measure the emission of, and personal exposure to workers, volatile organic compound (VOC) during paint spraying on a construction site. Needle trap samplers (NTSs), which are a green solid phase microextraction sampling technology, were used to obtain air samples at a large music exhibition center. The standard active sampling method using charcoal tubes and a personal air pump, Method 1501, was simultaneously utilized at the sampling sites to assess the workers' VOC exposures...
September 18, 2017: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
https://www.readbyqxmd.com/read/28918281/distribution-of-vocs-in-urban-and-rural-atmospheres-of-subtropical-india-temporal-variation-source-attribution-ratios-ofp-and-risk-assessment
#3
Amit Kumar, Deepak Singh, Krishan Kumar, Braj Bihari Singh, Vinod Kumar Jain
This paper reports the first study which comprises the seasonal, diurnal variability, source characterization, ozone forming potential and risk assessment of volatile organic compounds (VOCs) at three sites (two urban and one rural) in the National Capital Territory of Delhi, India. The study was performed during three seasons of the year 2013-14 and two different categories of VOCs (aromatics and halogenated) have been selected. The study used the sampling and analytical procedures of NIOSH methods. Results showed that the mean concentration of sum of VOCs (∑VOC) is significantly higher at urban sites (110...
September 14, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28918273/volatile-and-semivolatile-emissions-from-the-pyrolysis-of-almond-shell-loaded-with-heavy-metals
#4
M A Martín-Lara, N Ortuño, J A Conesa
Heavy metal-loaded almond shell was subjected to pyrolysis to understand the effect of the presence of different heavy metals on its thermal degradation. Pyrolysis behavior of native and metal-loaded samples was studied by thermogravimetric analysis. Similar shapes of thermogravimetric curves indicate that the presence of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and lead (Pb) did not change the main degradation pathways of almond shell. However, the temperature at which the decomposition in each stage takes place at a higher rate and char yield was considerably modified by the presence of Cr and Ni...
September 14, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28918122/pre-harvest-uv-c-irradiation-triggers-vocs-accumulation-with-alteration-of-antioxidant-enzymes-and-phytohormones-in-strawberry-leaves
#5
Yanqun Xu, Zisheng Luo, Marie Thérèse Charles, Daniel Rolland, Dominique Roussel
Recent studies have highlighted the biological and physiological effects of pre-harvest ultraviolet (UV)-C treatment on growing plants. However, little is known about the involvement of volatile organic compounds (VOCs) and their response to this treatment. In this study, strawberry plants were exposed to three different doses of UV-C radiation for seven weeks (a low dose: 9.6kJm(-2); a medium dose: 15kJm(-2); and a high-dose: 29.4kJm(-2)). Changes in VOC profiles were investigated and an attempt was made to identify factors that may be involved in the regulation of these alterations...
September 8, 2017: Journal of Plant Physiology
https://www.readbyqxmd.com/read/28917787/gas-chromatographic-mass-spectrometric-analysis-of-urinary-volatile-organic-metabolites-optimization-of-the-hs-spme-procedure-and-sample-storage-conditions
#6
Tanja Živković Semren, Irena Brčić Karačonji, Toni Safner, Nataša Brajenović, Blanka Tariba Lovaković, Alica Pizent
Non-targeted metabolomics research of human volatile urinary metabolome can be used to identify potential biomarkers associated with the changes in metabolism related to various health disorders. To ensure reliable analysis of urinary volatile organic metabolites (VOMs) by gas chromatography-mass spectrometry (GC-MS), parameters affecting the headspace-solid phase microextraction (HS-SPME) procedure have been evaluated and optimized. The influence of incubation and extraction temperatures and times, coating fibre material and salt addition on SPME efficiency was investigated by multivariate optimization methods using reduced factorial and Doehlert matrix designs...
January 1, 2018: Talanta
https://www.readbyqxmd.com/read/28917778/determination-of-volatile-organic-compounds-in-eucalyptus-fast-pyrolysis-bio-oil-by-full-evaporation-headspace-gas-chromatography
#7
Nathalya Kosinski Lima, André Romualdo Lopes, Palimecio Gimenes Guerrero, Carlos Itsuo Yamamoto, Fabricio Augusto Hansel
This paper reports a full evaporation (FE) headspace gas chromatographic (HS-GC) method for the determination of the volatile organic compounds (VOCs) in bio-oil (i.e. methanol, ethanol, acetone, acetic acid and furfural). The method uses a 4μL sample of bio-oil in a headspace vial (ca. 20mL). Complete evaporation of the compounds was achieved after seven minutes at 90°C. The method showed good precision and accuracy for methanol, ethanol, acetone and acetic acid. The recovery of furfural was low (74.3%)...
January 1, 2018: Talanta
https://www.readbyqxmd.com/read/28915496/solid-phase-microextraction-coupled-to-gas-chromatography-mass-spectrometry-followed-by-multivariate-data-analysis-for-the-identification-of-volatile-organic-compounds-as-possible-biomarkers-in-lung-cancer-tissues
#8
Federica Bianchi, Nicolò Riboni, Paolo Carbognani, Letizia Gnetti, Enrico Dalcanale, Luca Ampollini, Maria Careri
Solid-phase microextraction and gas chromatography-mass spectrometry followed by multivariate data analysis were used to analyze lung tissues from both healthy and carcinogenic patients. A total of 78 volatile compounds belonging to different chemical classes were identified, seven of which were able to discriminate between the two groups. Discriminant analysis allowed to correctly classify 98.3% of the cases. By using the leave-one-method, 100% of the cross-validated samples belonging to the "tumor" group was correctly classified, whereas 2 cross-validated healthy samples out of 48 were erroneously allocated in the "tumor" group...
September 6, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28913850/hyphenation-of-proton-transfer-reaction-mass-spectrometry-with-thermal-analysis-tg-ptr-ms-for-monitoring-the-thermal-degradation-of-retinyl-acetate
#9
Irene Peinado, Marco Mason, Franco Biasioli, Matteo Scampicchio
RATIONALE: The processing of retinyl acetate, a vitamin and biomarker, at high temperatures causes significant decomposition of the compound and thus loss of its activity. The rate of mass loss can be conveniently studied by thermogravimetry (TG). However, this technique generally fails to reveal which compounds have been evolved from the compound. In this work we propose a new hyphenation approach to continuously monitor the thermal decomposition of retinyl acetate and follow the evolution of specific volatile organic compounds (VOCs)...
September 14, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28911223/direct-sampling-and-analysis-of-atmospheric-particulate-organic-matter-by-proton-transfer-reaction-mass-spectrometry
#10
Markus Muller, Philipp Eichler, Barbara D'Anna, Wen Tan, Armin Wisthaler
We report on a new method for analyzing atmospheric submicrometer particulate organic matter which combines direct particle sampling and volatilization with on-line chemical ionization mass spectrometric analysis. Technically, the method relies on the combined use of a CHARON ("Chemical Analysis of Aerosol On-line") particle inlet and a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS). Laboratory studies on target analytes showed that the ionization conditions in the PTR-ToF-MS lead to extensive fragmentation of levoglucosan and cis-pinonic acid, while protonated oleic acid and 5-cholestane molecules remain intact...
September 15, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28910585/analysis-of-glycols-glycol-ethers-and-other-volatile-organic-compounds-present-in-household-water-based-hand-pump-sprays
#11
Tsuyoshi Kawakami, Kazuo Isama, Toshiko Tanaka-Kagawa, Hideto Jinnno
The aim of this investigation is to clarify the types and concentrations of VOCs present in various commercial household water-based hand pump spray products used in Japan, and to estimate their average concentrations in indoor air when the spray product is used. We selected glycol and glycol ethers as the main target compounds, as these chemicals were detected at high frequencies and concentrations in a national survey of Japanese indoor air pollution. The extraction of these chemicals using graphite carbon cartridges was examined, with good recoveries and reproducibilities being obtained...
September 14, 2017: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
https://www.readbyqxmd.com/read/28910313/a-detailed-comparison-of-analysis-processes-for-mcc-ims-data-in-disease-classification-automated-methods-can-replace-manual-peak-annotations
#12
Salome Horsch, Dominik Kopczynski, Elias Kuthe, Jörg Ingo Baumbach, Sven Rahmann, Jörg Rahnenführer
MOTIVATION: Disease classification from molecular measurements typically requires an analysis pipeline from raw noisy measurements to final classification results. Multi capillary column-ion mobility spectrometry (MCC-IMS) is a promising technology for the detection of volatile organic compounds in the air of exhaled breath. From raw measurements, the peak regions representing the compounds have to be identified, quantified, and clustered across different experiments. Currently, several steps of this analysis process require manual intervention of human experts...
2017: PloS One
https://www.readbyqxmd.com/read/28894051/standardization-of-the-collection-of-exhaled-breath-condensate-and-exhaled-breath-aerosol-using-a-feedback-regulated-sampling-device
#13
Brett R Winters, Joachim D Pleil, Michelle M Angrish, Matthew A Stiegel, Terence H Risby, Michael C Madden
Exhaled breath condensate (EBC) and associated exhaled breath aerosols (EBA) are valuable non-invasive biological media used for the quantification of biomarkers. EBC contains exhaled water vapor, soluble gas-phase (polar) organic compounds, ionic species, plus other species including semi- and non-volatile organic compounds, proteins, cell fragments, DNA, dissolved inorganic compounds, ions, and micro-biota (bacteria and viruses) dissolved in the co-collected EBA. EBC is collected from subjects who breathe "normally" through a chilled tube assembly for approximately 10 minutes and is then harvested into small vials for analysis...
September 12, 2017: Journal of Breath Research
https://www.readbyqxmd.com/read/28892796/a-solid-composite-microbial-inoculant-for-the-simultaneous-removal-of-volatile-organic-sulfide-compounds-preparation-characterization-and-its-bioaugmentation-of-a-biotrickling-filter
#14
Dong-Zhi Chen, Xiang-Yu Zhao, Xiao-Ping Miao, Jing Chen, Jie-Xu Ye, Zhuo-Wei Cheng, Shi-Han Zhang, Jian-Meng Chen
Volatile organic sulfide compounds (VOSCs) are usually resistant to biodegradation, thereby limiting the performance of traditional biotechnology dealing with waste gas containing such pollutants especially in mixture. In this study, a solid composite microbial inoculant (SCMI) was prepared to remove dimethyl sulfide (DMS) and propanethiol (PT). Given that the DMS degradation activity of Alcaligenes sp. SY1 is inducible and the PT-degradation activity of Pseudomonas putida S-1 is constitutive, different strategies are designed for cell cultivation to obtain high VOSC removal rates of SCMI...
September 1, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28887851/comparison-of-four-extraction-methods-for-analysis-of-volatile-hop-derived-aroma-compounds-in-beer
#15
Tobias M Richter, Graham T Eyres, Patrick Silcock, Phil J Bremer
The volatile organic compound profile in beer is derived from hops, malt, yeast, and interactions between the ingredients, making it very diverse and complex. Due to the range and diversity of the volatile organic compounds present, the choice of the extraction method is extremely important for optimal sensitivity and selectivity. This study compared four extraction methods for hop-derived compounds in beer late hopped with Nelson Sauvin. Extraction capacity and variation were compared for headspace solid phase micro extraction, stir bar sorptive extraction, headspace sorptive extraction, and solvent assisted flavour evaporation...
September 9, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28887468/the-network-of-plants-volatile-organic-compounds
#16
Gianna Vivaldo, Elisa Masi, Cosimo Taiti, Guido Caldarelli, Stefano Mancuso
Plants emission of Volatile Organic Compounds (VOCs) is involved in a wide class of ecological functions, as VOCs play a crucial role in plants interactions with biotic and abiotic factors. Accordingly, they vary widely across species and underpin differences in ecological strategy. In this paper, VOCs spontaneously emitted by 109 plant species (belonging to 56 different families) have been qualitatively and quantitatively analysed in order to provide an alternative classification of plants species. In particular, by using bipartite networks methodology from Complex Network Theory, and through the application of community detection algorithms, we show that is possible to classify species according to chemical classes such as terpenes and sulfur compounds...
September 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28884438/development-of-a-standard-reference-material-containing-22-chlorinated-hydrocarbon-gases-at-1%C3%A2-%C3%AE-mol-mol-in-nitrogen
#17
Ning Li, Jian Du, Jing Yang, Qiang Fan, Wen Tian
A gas standard mixture containing 22 chlorinated hydrocarbons in high purity nitrogen was prepared using a two-step weighing method and a gasifying apparatus developed in-house. The concentration of each component was determined using a gas chromatograph with flame ionization detection (GC/FID). Linear regression analysis of every component was performed using the gas standard mixture with concentrations ranging from 1 to 10 μmol/mol, showing the complete gasification of volatile organic compound (VOCs) species in a selected cylinder...
September 8, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28873739/effect-of-symbiotic-interaction-between-a-fructooligosaccharide-and-probiotic-on-the-kinetic-fermentation-and-chemical-profile-of-maize-blended-rice-beverages
#18
Ana Luiza Freire, Cintia Lacerda Ramos, Rosane Freitas Schwan
There is an important demand for the development of new non-dairy probiotic beverages in the functional food market. This work aimed to develop new fermented beverages from maize and rice. Lactobacillus plantarum CCMA 0743, Torulaspora delbrueckii CCMA 0235, and the commercial probiotic Lactobacillus acidophilus LACA 4, were used as a mixed starter culture. Two prebiotic concentrations, 20 and 50g/L fructooligosaccharide (FOS) were tested. The growth of L. acidophilus LACA 4 was favored by 50g/L FOS and after refrigerated storage at 4°C for 28days, its population remained above 10(7)CFU/mL...
October 2017: Food Research International
https://www.readbyqxmd.com/read/28873674/the-effect-of-algae-diets-skeletonema-costatum-and-rhodomonas-baltica-on-the-biochemical-composition-and-sensory-characteristics-of-pacific-cupped-oysters-crassostrea-gigas-during-land-based-refinement
#19
Jasper van Houcke, Isabel Medina, Hanne K Maehre, Josiane Cornet, Mireille Cardinal, Jozef Linssen, Joop Luten
Oyster refinement, a common practice in France, is aimed at increasing the weight of oyster tissue and influencing the taste properties of the refined oysters. Refinement usually takes place in land-based systems where the oysters are fed with relatively high concentrations of microalgae. In this study the impact of feeding Skeletonema costatum and Rhodomonas baltica on the biochemical composition and sensory characteristics of Pacific cupped oysters (Crassostrea gigas) from the Eastern Scheldt during land-based refinement was studied...
October 2017: Food Research International
https://www.readbyqxmd.com/read/28873560/portraying-and-tracing-the-impact-of-different-production-systems-on-the-volatile-organic-compound-composition-of-milk-by-ptr-quad-ms-and-ptr-tof-ms
#20
Ningjing Liu, Alex Koot, Kasper Hettinga, Jacob de Jong, Saskia M van Ruth
The aim of this study was to discover the unique volatile compositional traits of retail milk from different production systems. Forty-four retail milk samples were analyzed, including organic milk (n=10), conventional milk (n=14) and pasture milk (n=20) from winter (n=22) and summer (n=22). Proton transfer reaction quadrupole mass spectrometry (PTR-(Quad)MS) was utilized to obtain the mass-resolved fingerprints (76 masses per sample) of volatile organic compounds (VOCs). Principal component analysis (PCA) and analysis of variance (ANOVA) were performed to evaluate the differences between the groups...
January 15, 2018: Food Chemistry
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