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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
#1
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/28431313/raman-spectroscopy-for-the-characterization-of-different-fractions-of-hemp-essential-oil-extracted-at-130%C3%A2-c-using-steam-distillation-method
#2
Muhammad Asif Hanif, Haq Nawaz, Saima Naz, Rubina Mukhtar, Nosheen Rashid, Ijaz Ahmad Bhatti, Muhammad Saleem
In this study, Raman spectroscopy along with Principal Component Analysis (PCA) is used for the characterization of pure essential oil (pure EO) isolated from the leaves of the Hemp (Cannabis sativa L.,) as well as its different fractions obtained by fractional distillation process. Raman spectra of pure Hemp essential oil and its different fractions show characteristic key bands of main volatile terpenes and terpenoids, which significantly differentiate them from each other. These bands provide information about the chemical composition of sample under investigation and hence can be used as Raman spectral markers for the qualitative monitoring of the pure EO and different fractions containing different active compounds...
April 1, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28429461/deodorization-of-arthrospira-platensis-biomass-for-further-scale-up-food-applications
#3
Sara P Cuellar-Bermúdez, Bertha Barba-Davila, Sergio O Serna-Saldivar, Roberto Parra-Saldivar, José Rodriguez-Rodriguez, Sandra Morales-Davila, Koen Goiris, Koenraad Muylaert, Cristina Chuck-Hernández
BACKGROUND: Given the importance of A. platensis as a potential food protein source, we achieve an affordable deodorization process that does not significantly affect the nutritional value of algae biomass. RESULTS: Ethanol, acetone or hexane were used to deodorize algae biomass and then to identify the profile of volatile compounds associated with its distinctive odor. Sensorial characteristics were improved in the biomass cake after the proposed solvent extraction...
April 21, 2017: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/28429390/microporous-polyamide-membranes-for-molecular-sieving-of-nitrogen-from-volatile-organic-compounds
#4
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/28426926/sorbent-material-characterization-using-in-tube-extraction-needles-as-inverse-gas-chromatography-column
#5
Xochitli L Osorio Barajas, Maik A Jochmann, Thorsten Hüffer, Beat Schilling, Torsten C Schmidt
In-tube extraction is a full automated enrichment technique, which consists of a stainless-steel needle, packed with sorbent material for the extraction of volatile and semi-volatile compounds. In principle, all particulate sorbents used for enrichment in air or headspace analysis can be used. However, the selection of the sorbents is merely based on empirical considerations rather than on experimental data, which is caused by a lack of knowledge about the relevant physicochemical properties of the sorbent...
April 20, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28426293/identifying-thermal-breakdown-products-of-thermoplastics
#6
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/28425827/efficacy-of-glycine-powder-air-polishing-combined-with-scaling-and-root-planing-in-the-treatment-of-periodontitis-and-halitosis-a-randomised-clinical-study
#7
Ayse Caygur, Mohammed R Albaba, Atilla Berberoglu, Hasan Guney Yilmaz
Introduction This study was performed to evaluate the clinical efficacy of using the Perio-Flow device (Electro Medical Systems, Nyon, Switzerland) adjunctively with mechanical instrumentation on periodontal parameters and halitosis. Materials and Methods Sixty patients who presented with a 4- to 6-mm probing pocket depth were recruited for the study. Patients were randomly assigned to scaling and root planing (SRP) or SRP + glycine powder air-polishing (GPAP). For both groups, the plaque index, gingival index, pocket depth, bleeding on probing, and clinical attachment level scores were recorded at baseline and 1 month...
January 1, 2017: Journal of International Medical Research
https://www.readbyqxmd.com/read/28423952/advances-in-the-research-of-celery-an-important-apiaceae-vegetable-crop
#8
Meng-Yao Li, Xi-Lin Hou, Feng Wang, Guo-Fei Tan, Zhi-Sheng Xu, Ai-Sheng Xiong
Celery (Apium graveolens L.), one of the most important vegetables in Apiaceae family, is cultivated worldwide and utilized in food and cosmetic industries because it is an excellent source of vitamins, phenolic compounds, volatile oils and other nutrients. Celery extracts possess various medicinal properties, such as antibacterial, anti-inflammatory and lowering blood glucose and serum lipid levels. With the rapid advancements in molecular biology and sequencing technology, studies on celery have been performed...
April 20, 2017: Critical Reviews in Biotechnology
https://www.readbyqxmd.com/read/28423428/aggregation-behavior-and-a-putative-aggregation-pheromone-in-sugar-beet-root-maggot-flies-diptera-ulidiidae
#9
Erik J Wenninger, Susan Y Emmert, Kelly Tindall, Hongjian Ding, Mark A Boetel, D Rajabaskar, Sanford D Eigenbrode
Male-biased aggregations of sugar beet root maggot, Tetanops myopaeformis (Röder) (Diptera: Ulidiidae), flies were observed on utility poles near sugar beet (Beta vulgaris L. [Chenopodiaceae]) fields in southern Idaho; this contrasts with the approximately equal sex ratio typically observed within fields. Peak observation of mating pairs coincided with peak diurnal abundance of flies. Volatiles released by individual male and female flies were sampled from 08:00 to 24:00 hours in the laboratory using solid-phase microextraction and analyzed using gas chromatography/mass spectrometry (GC/MS)...
January 1, 2017: Journal of Insect Science
https://www.readbyqxmd.com/read/28423424/field-evaluation-of-potential-pheromone-lures-for-lygus-lineolaris-hemiptera-miridae-in-the-mid-south
#10
Katherine A Parys, David R Hall
Plant bugs (Hemiptera: Miridae) are phytophagous pests of cultivated plants around the world. In the mid-South region of the United States, Lygus lineolaris (Palisot de Beauvois) is a primary pest of cotton, and causes economic damage. Previously published research about the volatiles produced by members of the genus Lygus, and other closely related groups, indicated that they produce blends of hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal. Varying ratios of the three compounds were loaded into pipette tips, and screened in combination with non-UV white sticky cards for attractiveness to field populations of L...
January 1, 2017: Journal of Insect Science
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
#11
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/28423217/in-vitro-discrimination-of-wound-associated-bacteria-by-volatile-compound-profiling-using-selected-ion-flow-tube-mass-spectrometry
#12
Elisabeth Alice Slade, Robin Michael Statham Thorn, Andrew M Lovering, Amber Young, Darren Michael Reynolds
AIMS: To determine if bacterial species responsible for clinically relevant wound infection produce specific volatile profiles that would allow their speciation. METHODS AND RESULTS: Selected-Ion Flow Tube-Mass Spectrometry in full mass scan mode was used to analyse headspace gases produced by wound-associated bacteria grown in vitro, so as to enable identification of bacterial volatile product ion profiles in the resulting mass spectra. Applying multivariate statistical analysis (hierarchical clustering and principal component analysis) to the resultant mass spectra enabled clear speciation...
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
#13
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
#14
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
#15
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/28421748/potential-contribution-of-fish-feed-and-phytoplankton-to-content-of-volatile-terpenes-in-cultured-pangasius-pangasianodon-hypophthalmus-and-tilapia-oreochromis-niloticus
#16
Raju Podduturi, Mikael Agerlin Petersen, Sultan Mahmud, Md Mizanur Rahman, Niels O G Jørgensen
Geosmin and 2-methylisoborneol are the most recognized off-flavors in freshwater fish, but terpenes may also contribute off-flavor in fish. We identified six monoterpenes, 11 sesquiterpenes and three terpene-related compounds in pangasius and tilapia from aquaculture farms in Bangladesh. Concentrations of most of the volatiles were below published odor thresholds, except for α-pinene, limonene, β-caryophyllene, α-humulene and β-ionone in tilapia, and limonene and β-ionone in pangasius. To identify sources of the terpenes, terpene profiles of fish feed and phytoplankton in the ponds were analyzed...
April 19, 2017: Journal of Agricultural and Food Chemistry
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
#17
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/28417328/characterization-and-pyrolysis-of-chlorella-vulgaris-and-arthrospira-platensis-potential-of-bio-oil-and-chemical-production-by-py-gc-ms-analysis
#18
Hanna N Almeida, Guilherme Q Calixto, Bruna M E Chagas, Dulce M A Melo, Fabio M Resende, Marcus A F Melo, Renata Martins Braga
Biofuels have been seen as potential sources to meet future energy demand as a renewable and sustainable energy source. Despite the fact that the production technology of first-generation biofuels is consolidated, these biofuels are produced from foods crops such as grains, sugar cane, and vegetable oils competing with food for crop use and agricultural land. In recent years, it was found that microalgae have the potential to provide a viable alternative to fossil fuels as source of biofuels without compromising food supplies or arable land...
April 17, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28417179/analysis-of-honeybush-tea-cyclopia-spp-volatiles-by-comprehensive-two-dimensional-gas-chromatography-using-a-single-stage-thermal-modulator
#19
Gaalebalwe Ntlhokwe, Andreas G J Tredoux, Tadeusz Górecki, Matthew Edwards, Jochen Vestner, Magdalena Muller, Lené Erasmus, Elizabeth Joubert, J Christel Cronje, André de Villiers
The applicability of comprehensive two-dimensional gas chromatography (GC×GC) using a single-stage thermal modulator was explored for the analysis of honeybush tea (Cyclopia spp.) volatile compounds. Headspace solid phase micro-extraction (HS-SPME) was used in combination with GC×GC separation on a non-polar × polar column set with flame ionisation (FID) detection for the analysis of fermented Cyclopia maculata, Cyclopia subternata and Cyclopia genistoides tea infusions of a single harvest season. Method optimisation entailed evaluation of the effects of several experimental parameters on the performance of the modulator, the choice of columns in both dimensions, as well as the HS-SPME extraction fibre...
April 17, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28417171/resolution-optimized-headspace-gas-chromatography-ion-mobility-spectrometry-hs-gc-ims-for-non-targeted-olive-oil-profiling
#20
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
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