TY - JOUR. T1 - Biological aspects of constructing volatile organic compound emission inventories. AU - Monson, Russell K.. AU - Lerdau, Manuel T.. AU - Sharkey, Thomas D.. AU - Schimel, David S.. AU - Fall, Ray. PY - 1995/11. Y1 - 1995/11. N2 - The: emission of volatile organic compounds (VOCs) from vegetation is subject to numerous biological controls. Past inventories have relied heavily on empirical models which are limited in their ability to simulate the response of organisms to short- and long-term changes in their growth environment. In this review we consider the principal biochemical, physiological and ecological controls over VOC emission with specific reference to how such controls can be included in ecosystem-level inventories. A distinction is made between longer-term biological controls over basal VOC emission rates (rates determined under a standard set of environmental conditions) and instantaneous biological and environmental controls over instantaneous VOC emission rates ...
Control of Odor and VOC Emissions at Wastewater Treatment Plants -Boston Harbor Case Study-. Siting of the new wastewater treatment plant (WWTP) for the Massachusetts Water Resources Authority (MWRA) in Boston was based on an assumption of mitigation of total reduced sulfur (TRS) and volatile organic compound (VOC) emissions. Collection and treatment of exhaust streams from potential emission sources was recommended. Best Available Control Technology (BACT) for VOC control was conservatively suggested to consist of wet scrubbing followed by carbon adsorption based on initial sampling performed in 1988 during facilities planning, which estimated uncontrolled VOC emissions in excess of 1000 tons per year. This concept was carried forward to the design phase in 1990, concurrent with an extensive air emissions testing and pilot treatment program at the MWRAs existing primary treatment plant. Results of the pilot program, however, indicated source VOC concentrations well below what was expected as a
Title:A Compendium of Volatile Organic Compounds (VOCs) Released By Human Cell Lines. VOLUME: 23 ISSUE: 20. Author(s):Wojciech Filipiak, Pawel Mochalski, Anna Filipiak, Clemens Ager, Raquel Cumeras, Cristina E. Davis, Agapios Agapiou, Karl Unterkofler and Jakob Troppmair. Affiliation:Daniel Swarovski Research Laboratory, Department of Visceral-, Transplant- and Thoracic Surgery, Innsbruck Medical University, Innsbruck, Austria. Keywords:Biomarker, Breath analysis, Cancer, GC-MS, Human cell lines, Standardization, Volatile organic compounds (VOCs), Volatilome.. Abstract:Volatile organic compounds (VOCs) offer unique insights into ongoing biochemical processes in healthy and diseased humans. Yet, their diagnostic use is hampered by the limited understanding of their biochemical or cellular origin and their frequently unclear link to the underlying diseases. Major advancements are expected from the analyses of human primary cells, cell lines and cultures of microorganisms. In this review, a ...
VOC emissions from melamine films and finish foils. The paper presents results of investigations on VOC emissions from melamine films and finish foils, i.e. materials used to refine surface of wood-based materials. Compound adsorption was carried out on the Tenax TA solid sorbent. Volatile organic compounds were analysed with the assistance of gas chromatography coupled with mass spectrometry and thermal desorption (GC/MS/TD). It was concluded, on the basis of the obtained research results, that the tested finishing materials were characterised by relatively low levels of noxious emissions ...
VOC emission profile is an important parameter to describe the building materials and consumer products for their impact on indoor air quality (IAQ). Emission profiles are dependent on the test conditions. It is therefore very important to standardize testing conditions in order to compare emission factors and decay constants reported by various testing laboratories. Standard chamber test conditions (Chamber temperature of 23 C, relative humidity of 50 %, air change rate of 1 ACH, and specimen loading ratio of 0.4 m{sup 2}/m{sup 3}) have been proposed for using small environment chamber (0.05 m{sup 3}) by an international consortium research program led by the Institute for Research in Construction, NRCC. VOC emissions (excluding formaldehyde) from three building materials, a particleboard, a carpet with rubber backing and a vinyl floor tile were measured under above defined test conditions. Samples of the chamber air were collected using multi-sorbent tubes during the chamber tests, and ...
Emission inventories defining regional and global biogenic volatile organic compounds (VOC) emission strengths are needed to determine the impact of VOC on atmospheric chemistry (oxidative capacity) and physics (secondary organic aerosol formation and effects). The aim of this work was to contribute with measurements of tree species from the poorly described tropical vegetation in direct comparison with the quite well-investigated, highly heterogeneous emissions from Mediterranean vegetation. VOC emission from sixteen plant species from the Mediterranean area were compared with twelve plant species from different environments of the Amazon basin by an emission screening at leaf level using branch enclosures. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS) and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was the most dominant compound emitted followed by monoterpenes, methanol and ...
P1.27 Studies of Volatile Organic Compounds in Ambient Air in New York City. Mohamed Bangura, Medgar Evers College, City University of New York, Brooklyn, NY; and J. Dick. Volatile organic compounds (VOCs) including benzene and its derivatives contribute significantly to the pollution of urban air; at low altitudes, VOCs also enhance ozone production. Monitoring VOC in urban air has important health implications, especially since asthma and other lung diseases in inner city communities are above the national average. In addition, weather variables such as wind speed, atmospheric pressure, temperature and humidity affect dispersal patterns and concentrations. Present methods for the determination of VOCs in ambient air are expensive and complex, simpler methods are required. Tetraglyme (tetraethylene glycol dimethyl ether) is used to scrub a variety of VOCs in ambient air. The chilled tetraglyme traps VOCs as the air is bubbled through it. The VOCs are dispersed in water, which is analyzed by ...
Article What is a Volatile Organic Compound (VOC)?. What is a Volatile Organic Compound (VOC)? Our products are known for monitoring many different gases, but if you look closely at the description of some of them, you will see that it mentions the ...
Uncorrected OCR) Abstract of thesis entitled. DEVELOPMENT OF PIEZOELECTRIC CRYST AL DETECTORS FOR SENSING BACTERIA IN WATER AND DETERMINING VOLATILE ORGANIC COMPOUNDS IN AIR. Submitted by. WongYukYan. for the Degree of Master of Philosophy at The University of Hong Kong. in January 2000. The applicability of piezoelectric (P/Z) crystal sensors as detectors for determining volatile organic compounds (VOCs) in air, and sensing bacteria in water, has been investigated in the present study. The detectors developed provide a simple and sensitive on-site method for determining total organic vapours in air for occupational health protection, and provide a specific and economic method for determining Salmonella in water for food poisoning. cases.. For VOC determination in workplace air, a light and portable P/Z crystal detector has been developed. To reduce the interference of high humidity on the monitoring of organic vapours, the moisture content in the air. sampled was removed by two different drying ...
TY - JOUR. T1 - TiO2 mediated photocatalytic oxidation of volatile organic compounds. T2 - Formation of CO as a harmful by-product. AU - Selishchev, D. S.. AU - Kolobov, N. S.. AU - Pershin, A. A.. AU - Kozlov, D. V.. PY - 2017/1/1. Y1 - 2017/1/1. N2 - Photocatalytic oxidation (PCO) of volatile organic compounds (VOCs) including acetone, alcohols and hydrocarbons was investigated in a static reactor using an FTIR in situ method. Three commercially available TiO2 powders and one TiO2 sample synthesized via thermal hydrolysis of titanyl sulfate were employed in the kinetic experiments. PCO reactions were conducted under different UV light intensities, initial concentrations of substrates, humidities, and temperatures. The formation of the final oxidation products and the kinetics of their accumulation were investigated. Analysis of the FTIR spectra revealed the formation of CO along with CO2 and H2O as final products in the oxidation of VOCs over all the TiO2 samples. No other final products were ...
Free Online Library: Laboratory evaluation of volatile organic compounds emissions from coated and uncoated oriented strandboard. by Forest Products Journal; Business Forest products industry Emissions (Pollution) Case studies Oriented strand board Volatile organic compounds Influence
The current standard is developed for the purpose of implementation of Environmental Protection Law of the Peoples Republic of China and Law of the Peoples Republic of China on Prevention and Control of Environmental Pollution by Solid Waste, protecting the environment, ensuring human health and standardizing the methods for determination of volatile organic compounds in solid waste. The current standard specifies the headspace-gas chromatography method for determination of volatile organic compounds in solid waste. The current standard is released for the first time. ...
The current standard is developed for the purpose of implementation of Environmental Protection Law of the Peoples Republic of China and Law of the Peoples Republic of China on Prevention and Control of Environmental Pollution by Solid Waste, protecting the environment, ensuring human health and standardizing the methods for determination of volatile organic compounds in solid waste. The current standard specifies the headspace-gas chromatography method for determination of volatile organic compounds in solid waste. The current standard is released for the first time.. ...
TY - JOUR. T1 - A wearable sensing system for assessment of exposures to environmental volatile organic compounds. AU - Chen, Cheng. AU - Tsow, Francis. AU - Xian, Xiaojun. AU - Forzani, Erica. AU - Tao, Nongjian. AU - Tsui, Raymond. PY - 2015. Y1 - 2015. N2 - A portable chemical sensing system that integrates sample preconcentration, separation and detection as well as wireless communication functionalities into a compact, wearable format can provide continuous and real-time monitoring of volatile organic compounds in the environment. The sensing modality relies on tuning forks coated with molecularly imprinted polymers that, in conjunction with sample preconcentration, offer selective detection down to parts-per-billion levels. The use of capillary columns allows individual components of complex mixtures to be detected at these highly sensitive levels even in the presence of interferents. The wireless capability facilitates the utilization of a paired smartphone as the user interface as well ...
Biogenic emissions of the volatile organic compounds isoprene and monoterpenes (BVOCs) can contribute to tropospheric ozone and secondary particle formation and have indirect effects on climate change. While there are few studies of BVOC emissions from European towns and cities, several studies in North America indicate that the urban tree canopy may be a significant source of BVOC compounds, contributing to ozone and particle formation in the urban air-shed. Here, BVOC emissions from the U.K. West Midlands (UKWM) metropolitan area were estimated and compared with anthropogenic VOC emission estimates, and with BVOC emission estimates for other urban and U.K. regions. Monoterpene and isoprene emission potential estimates for the UKWM urban land-use classes spanned as much as two orders of magnitude, from 17-104 g·km-2·h-1 and from 42-1570 g·km-2·h-1, respectively. Isoprene emission potential estimates for the UKWM urban land classes (42-530 g·km-2·h-1) were of the same order of magnitude as ...
The purposes of this project were to develop and validate a sampling and analysis methodology for determination of volatile organic compound (VOC) concentrations in health care settings and to model results for incorporation into a job-exposure matrix. This project was part of a larger epidemiologic study to assess exposures to asthmagenic cleaning and disinfecting products among healthcare worker
The introduction of proton transfer reaction mass spectrometry (PTR-MS) for fast response measurements of volatile organic compounds (VOC) has enabled the use of eddy covariance methods to investigate VOC fluxes on the ecosystem scale. In this study PTR-MS flux measurements of VOC were performed over agricultural grassland during and after a cut event. Selected masses detected by the PTR-MS showed fluxes of methanol, acetaldehyde, and acetone. They were highest directly after cutting and during the hay drying phase. Simultaneously, significant fluxes of protonated ion masses 73, 81, and 83 were observed. Due to the limited identification of compounds with the PTR-MS technique, GC-MS and GC-FID-PTR-MS techniques were additionally applied. In this way, ion mass 73 could be identified as 2-buta-none, mass 81 mainly as (Z)-3-hexenal, and mass 83 mainly as the sum of (Z)-3-hexenol and hexenyl acetates. Hexenal, hexenols, and the hexenyl ace-tates are mostly related to plant wounding during cutting. ...
An analytical method has been established for the quantitative determination of 48 gaseous volatile organic compounds (VOCs) that were detected in the outdoor environment in Western Singapore by Thermal Desorption Gas Chromatography Mass Spectrometry (TD-GCMS). Tenax/Carbopack X multi-sorbent tubes were evaluated for active sampling performance and the method was validated using VOC standard solutions. The procedure exhibited repeatability with relative standard deviation (%RSD) values ≤ 10%, linearity with R2 values ≥ 0.99 for concentrations from 0.02 to 500 ng, VOC standards breakthrough ≤ 5% , tube desorption efficiencies ~100% and the majority of recoveries were between 61% to 120%. 30 mL/min flow rate coupled with sampling volumes of 1 L and 5 L gave the best results for sampling breakthrough and reproducibility during air sampling. Most of the target analytes exhibited acceptable breakthrough ≤ 5%, reproducibility ≤ 20% and method detection limits below 0.5 ppbv. The analyte ...
The concentrations of formaldehyde, individual volatile organic compounds (VOCs) and total VOCs (TVOC) were measured in four new manufactured houses on three occasions over nine months following construction. Ventilation rates were also measured. A mass-balance model was used to calculate area-specific emission rates of the target analytes. Formaldehyde concentrations were all less than a guideline value of 50 ppb. One-half of the 58 target VOCs had median concentrations at or below 1 ppb. The most abundant VOCs were terpene hydrocarbons, ethylene glycol, hexanal, 2-butanone and acetic acid. Concentrations of hexanal, other aldehydes and acetic acid often exceeded their odor thresholds. The median TVOC concentration was 1.6 mg m-3. In general, there were no large decreases in the emission rates of individual VOCs or TVOC over the course of the study. The data suggested that wood products were a dominant source of VOCs in all houses.. ...
Air sampling, using sorbents, thermal desorption and gas chromatography, is a versatile method for identifying and quantifying trace levels of volatile organic compounds (VOCs). Thermal desorption can provide high sensitivity, appropropriate choices of sorbents and method parameters can accommodate a wide range of
Formaldehyde Tester I Application Formaldehyde Tester I Application Formaldehyde mattress mattress tester is mainly applied to formaldehyde, VOC emission test
On May 25, 21017 Environment and Climate Change Canada (ECCC) announced proposed regulations to reduce methane and VOC emissions from Canadas oil and gas
Formaldehyde (HCHO) columns measured from space provide constraints on emissions of volatile organic compounds (VOCs). Quantitative interpretation requires characterization of errors in HCHO column retrievals and relating these columns to VOC emissions. Retrieval error is mainly in the air mass factor (AMF) which relates fitted backscattered radiances to vertical columns and requires external information on HCHO, aerosols, and clouds. Here we use aircraft data collected over North America and the Atlantic to determine the local relationships between HCHO columns and VOC emissions, calculate AMFs for HCHO retrievals, assess the errors in deriving AMFs with a chemical transport model (GEOS-Chem), and draw conclusions regarding space-based mapping of VOC emissions. We show that isoprene drives observed HCHO column variability over North America; HCHO column data from space can thus be used effectively as a proxy for isoprene emission. From observed HCHO and isoprene profiles we find an HCHO molar ...
Oxygenated volatile organic compounds ((O)VOCs) contribute to ozone formation, affect the oxidising capacity of the troposphere and are sources of growth, and in some cases formation, of aerosols. It is therefore important to identify and quantify sources of (O)VOCs in the troposphere. In the late 1990s a unique technique for quantification of organic trace gas species, proton transfer reaction mass spectrometry (PTR-MS) was developed. PTR-MS potentially offers rapid response and high sensitivity without the need for sample preconcentration. Concentrations can be derived from the PTR-MS either by calibration or can be calculated from measured ion count rates and kinetic considerations. In this work, the methodology of PTR-MS application is critically assessed. The uncertainties and inaccuracies associated with each parameter employed in the calculation of concentrations are reviewed. This includes a critical appraisal of models for the calculation of the collisional rate constant currently ...
The biogenic volatile organic compounds (VOCs) in the ambient air of the Hobart Air Shed and in the emissions from selected Tasmanian native trees and understorey shrubs were measured. The emission rates were then related to the plants essential oils content, which had been extracted by hydro-distillation. The VOCs in the ambient air of native forests have not previously been studied in Australia. This study used multi-adsorbent cartridge adsorption/thermal desorption and Gas Chromatography-Mass Spectrometry. The type, quantity, source and variation of the VOCs were investigated. The concentration of VOCs in the atmosphere surrounding vegetation in the Hobart Air Shed was determined. In all, 129 compounds of eight classes were detected. Ofthese, 11 compounds were National Pollutant Inventory substances and 32 were considered biogenic; however, this estimate is conservative. The concentration of total VOCs in these ambient air measurements varied between 4.43 x 10- 10 g L- 1 and 3.04 x 10-9 g ...
Volatile organic compounds (VOCs) and indoor air quality, what VOCs are and where they come from, health concerns, how to avoid VOCs, and proper ventilation tips.
Abstract Volatile organic compounds (VOCs) are trace substances found in exhaled breath. In the past years numerous studies have underlined the close connection between VOCs and various diseases. Several VOCs classes have been identified, such as: hydrocarbons, sulfur containing VOCs, amino containing VOCs or oxygen containing VOCs. The specific focus of the present review is to address the topic of VOCs fingerprint in several specific diseases such as: lung disease, heart disease, breast disease, Cohns disease, ulcerative colitis, gastro-enteric affections, schizophrenia and in vitro cell cultures…. ...
Predators and parasitoids are important natural enemies of herbivorous insects. By reducing the abundance of herbivores, they can help protect plants from damage. Parasitoids in particular can use herbivore-induced plant volatiles (HIPVs) as host-searching cues [1, 2]. Such volatile-mediated tritrophic interactions have a considerable potential to shape ecosystem dynamics [3], but it remains unclear to what extend the plant signals are emitted by the plant to specifically attract natural enemies of herbivores [4]. If HIPVs are indeed emitted by the plant to attract the third tropic level, specificity of the signals should be an important aspect of the interactions [5]. This is particularly relevant under natural conditions, where plants are often attacked by non-hosts or by multiple herbivores simultaneously. While specialist parasitoids can distinguish between plants attacked by hosts and plants attacked by non-hosts using HIPV cues [6], the impact of non-hosts feeding on the same plant as the ...
Fungi are implicated in poor indoor air quality and may pose a potential risk factor for building/mold related illnesses. Fungi emit numerous volatile organic compounds (VOCs) as alcohols, esters, ethers, ketones, aldehydes, terpenoids, thiols, and their derivatives. The toxicity profile of these VOCs has never been explored in a model organism, which could enable the performance of high throughput toxicological assays and lead to a better understanding of the mechanism of toxicity. We have established a reductionist Drosophila melanogaster model to evaluate the toxicity of fungal VOCs. In this report, we assessed the toxicity of fungal VOCs emitted from living cultures of species in the genera, Trichoderma, Aspergillus, and Penicillium and observed a detrimental effect on larval survival. We then used chemical standards of selected fungal VOCs to assess their toxicity on larval and adult Drosophila. We compared the survival of adult flies exposed to these fungal VOCs with known industrial toxic ...
Altech provides accurate and fast measurements of VOC (Volatile Organic Compounds). We offer complete VOC CEMS or discrete analyzers.
In this study, single-lung ventilation was used to detect differences in the volatile organic compound (VOCs) profiles between lung tissues in healthy and affected lungs. In addition, changes that occurred after lung cancer resection in both the VOCs profiles of exhaled breath from ipsilateral and contralateral lungs and the VOCs profiles of exhaled breath and blood sample headspaces were also determined. Eighteen patients with non-small cell carcinoma were enrolled. Alveolar breath samples were taken separately from healthy and diseased lungs before and after the tumor resection. Solid phase microextraction-gas chromatography/mass spectrometry was used to assess the exhaled VOCs of the study participants. The VOCs exhibited significant differences between the contralateral and ipsilateral lungs before surgery, the contralateral and ipsilateral lungs after surgery, the ipsilateral lungs before and after surgery, and the blood samples from before and after surgery; 12, 19, 12 and 5 characteristic ...
Volatile organic compounds are chemicals used to manufacture and maintain building materials, interior furnishing, cleaning products and personal care products. Volatile means that these chemicals evaporate or can easily get into the air at room temperature. Organic means these chemicals are carbon based. The term chemical emissions refers to VOCs as they evaporate into the air from products.. Studies by the EPA and other researchers from the New York Department of Health, have found that VOCs are common in indoor environments and that their levels may be two to a thousand times higher than outdoors. There may be anywhere from 50 to hundreds of individual VOCs in the indoor air at any one time. Some may produce objectionable odors at very low levels, but many have no noticeable smell.. ...
We use a continuous 6-year record (1996-2001) of GOME satellite measurements of formaldehyde (HCHO) columns over east and south Asia to improve regional emission estimates of reactive nonmethane volatile organic compounds (NMVOCs), including isoprene, alkenes, HCHO, and xylenes. Mean monthly HCHO observations are compared to simulated HCHO columns from the GEOS-Chem chemical transport model using state-of-science, bottom-up emission inventories from Streets et al. (2003a) for anthropogenic and biomass burning emissions and Guenther et al. (2006) for biogenic emissions (MEGAN). We find that wintertime GOME observations can diagnose anthropogenic reactive NMVOC emissions from China, leading to an estimate 25% higher than Streets et al. (2003a). We attribute the difference to vehicular emissions. The biomass burning source for east and south Asia is almost 5 times the estimate of Streets et al. (2003a). GOME reveals a large source from agricultural burning in the North China Plain in June ...
Analyses for Volatile Organic Compound Monitoring were conducted under procedures using concepts of EPA Method TO-15 Determination of Volatile Organic Compounds (VOCs) in Air Collected in Specially-Prepared Canisters and Analyzed by Gas Chromatography/Mass Spectrometry (GC/MS) (1999).Special quality assurance requirements for these activities were detailed in the Quality Assurance Project Plan for Volatile Organic Compound Monitoring, prepared by WTS. CEMRC personnel wrote procedures for this project under the CEMRC Quality Assurance Plan, which were verified, validated, and placed in the CEMRC Document Control Program. Procedures were composed to include QA requirements from EPA Method TO-15 and all WIPP documents relevant to the Confirmatory Monitoring Program. See Table 4-2 for a list of CEMRC Procedures for Confirmatory Monitoring.. In November 2006, a WIPP permit modification incorporated an expansion of sampling in the Volatile Organic Compounds Monitoring Program. Originally, the ...
An air-conditioned coach is an important form of transportation in modern motorized society; as a result, there is an increasing concern of in-vehicle air pollution. In this study, we aimed to identify and quantify the levels of volatile organic compounds (VOCs) and carbonyl compounds (CCs) in air samples collected from the cabins of newly produced, medium- and large-size coaches. Among the identified VOCs and CCs, toluene, ethylbenzene, xylene, formaldehyde, acetaldehyde, acrolein/acetone, and isovaleraldehyde were relatively abundant in the cabins. Time was found to affect the emissions of the contaminants in the coaches. Except for benzaldehyde, valeraldehyde and benzene, the highest in-vehicle concentrations of VOCs and CCs were observed on the 15th day after coming off the assembly line, and the concentrations exhibited an approximately inverted U-shaped pattern as a function of time. Interestingly, this study also showed that the interior temperature of the coaches significantly affected the VOCs
Volatile Compounds Profile of Sous-Vide Cooked Pork Cheeks as Affected by Cooking Conditions Vacuum Packaging, Temperature and Time. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Learn more about volatile organic compounds (VOC) which are human-made contaminants used & produced in the processing of multiple products and materials.
The FLIR GF320 is an IR camera for optical gas imaging. It visualizes and pinpoints leaks of Volatile Organic Compounds (VOCs), without the need to shut down the operation. This portable camera can greatly improve operator safety, by detecting emissions at a safe distance.
ABSTRACTVolatile organic compounds (VOCs) emitted from smoldering mosquito coils containing various atomic hydrogen/carbon (H/C) ratios in different relative humidity were examined. The concentrations of individual VOCs were determined using a preconcentrator-gas chromatography/mass spectrometer (GC/MS) and a flame ion detector (FID). Up to 72 VOCs were found. It is noteworthy that benzene and 1,3-butadiene, human carcinogenic substances, were emitted by all tested mosquito coils during burning. The five types of mosquito coils studied had atomic H/C ratios ranging from 1.23 to 1.57, yielding total VOC emission rates and factors of 7,295.72–14,308.17 µg hr–1 and 3,192.78–6,835.03 µg g–1, respectively. VOC emissions were significantly influenced by the carbon, hydrogen and oxygen contents of coils. According to the analyses of VOC emissions, mosquito coils containing the lowest H/C ratio, a low oxygen content, with suitable additives such as CaCO3 are recommended for
Volatile organic compounds (VOCs) emitted into headspace over discrete electronic components including resistors, capacitors, diodes, transistors, and transformers were i..
Applied Technical Services wants to help keep clients compliant with industry regulations and consumer products safe from Volatile Organic Compounds. With our newly acquired Thermal Desorption unit, we can test all kinds of parts for VOCs according to VDA 278.
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…
A nonrandom group of 40 volunteers participated in a study to determine the level of correlation between three methods of sampling for volatile organic compounds (VOC): organic vapor badges, charcoal tubes, and blood VOC levels. Each of 40 volunteers provided blood samples for analysis. Nineteen subjects wore organic vapor badges for at least 5 hours, and 24 subjects provided personal breathing zo
The use of volatile organic compounds VOCs to detect mold growth in damp buildings depends on a comprehensive knowledge of the biosynthetic pathways available to indoor molds as well as their biological variation. Recent reports concerning VOCs formed during the growth of molds from damp buildings on laboratory substrates indicate considerable...
The volatile organic compound ether is widely used as an industrial solvent and easily released to the environment. Our previous research indicated that ether triggers reactive oxygen species (ROS) production and activates ethylene biosynthetic genes and defense gene expressions in tomato. In the present study, we investigated the effect of ether on cell responses and gene expressions in Arabidopsis and compared the ROS and phytohormones produced in Arabidopsis and tomato plants in response to different air pollutants (O3 vs. ether). Ether induced the sequential production of superoxide anion and hydrogen peroxide in Arabidopsis. Ether also triggered expressions of ethylene, salicylic acid and jasmonic acid biosynthetic genes. The temporal expression patterns of MAP kinase and protein phosphatase genes are in good accordance with those of the ethylene and salicylic acid biosynthetic genes, suggesting that induction of these phytohormone biosynthesis were through signaling pathways including both
92C35; 92C45; 93B07; 93C10; Acetone; Applications of Mathematics; Breath gas analysis; Mathematical and Computational Biology; Modeling; Volatile organic compounds ...
92C35; 92C45; 93B07; 93C10; Acetone; Applications of Mathematics; Breath gas analysis; Mathematical and Computational Biology; Modeling; Volatile organic compounds ...
Pilot plant development of adsorption and PAO hybrid processes for the treatment of volatile organic compounds that cause odor.,Main projects completed
Chlorinated volatile organic compounds (CVOCs) are toxic chemical entities emitted invariably from stationary thermal operations when a trace of chlorine is present. Replacing the high-temperature destruction operations of these compounds with catalytic oxidation has led to the formulation of various potent
TY - JOUR. T1 - Principles and applications of comprehensive two-dimensional gas chromatography. AU - Marriott, Philip. AU - Shellie, Robert. PY - 2002/1/1. Y1 - 2002/1/1. N2 - This issue of Trends in Analytical Chemistry celebrates 50 years of gas chromatography (GC) - the greatest enabling technology for chemical analysis of volatile compounds. However, what may be considered the most powerful separation tool in GC - comprehensive two-dimensional gas chromatography (GC×GC) - is a development born of the 1990s. It was first described and almost fully established in the last decade of the twentieth century. The coming decades can be expected to see it flourish into a major operating mode of GC, when applications and fundamental principles will be further expanded, and, most importantly, its universal acceptance will be unquestioned. This article describes why the pioneers of GC×GC have so much faith in the new opportunities afforded by this exciting technology.. AB - This issue of Trends in ...
Comprehensive two-dimensional gas chromatography (GC×GC) is a high resolution and high sensitivity technique. It is especially suitable for the separation and identification of analytes in complex mixtures. Focused on the characterization of complex mixtures, a series of method and application studies using GC×GC have been carried out. Although comprehensive two-dimensional gas chromatography (GC×GC) can offer high resolution and sensitivity compared with traditional one-dimensional gas chromatography (1DGC), sample preparation is still essential for trace component analysis. An on-column cold trap device was used as a part of GC×GC or GC×GC combined with time-of-flight mass spectrometry (TOFMS) systems. The on-column cold trap device using a homemade double layer CO2 jet was mounted on the GC×GC or GC×GC-TOFMS, and performed at -60 ℃-70 cryogenic ℃temperature. Based on large volume injection, the trace compounds were focused at the head of column by cold trap and stationary phase, ...
GARBARINO, JUAN A et al. VOLATILE COMPOUNDS OF LITHRAEA CAUSTICA (LITRE) DETERMINATED BY SOLID PHASE MICRO-EXTRACTION (SPME). Bol. Soc. Chil. Quím. [online]. 2002, vol.47, n.4, pp.567-569. ISSN 0366-1644. http://dx.doi.org/10.4067/S0366-16442002000400030.. The head space of the aerial parts of Lithraea caustica was analyzed by Solid Phase Micro-Extraction (SPME) technique, obtaining as main volatile compounds the monoterpenes, myrcene, a -pinene, , p-cymene and limonene, as well as the sesquiterpene caryophylene.. Palabras clave : Lithraea caustica; Anacardiaceae; Solid Phase Micro-Extraction; head space components; monoterpenes, sesquiterpenes. ...
This article aims to investigate the use and benefits of using comprehensive two-dimensional gas chromatography (GC x GC) and structure-activity relationship modeling for screening and prioritization of organic contaminants in complex matrices. The benefit of applying comprehensive screening techniques to samples with high organic contaminant content is primarily that compounds with diverse physicochemical properties can be analyzed simultaneously. Here, a heavily contaminated industrial area was surveyed for organic pollutants by analyzing soil, sediment, and surface water samples. The hazard of the pollutants were ranked using SARs. The water samples were liquid-liquid extracted using dichloromethane and directly analyzed by GC x GC-time-of-flight mass spectrometry (GC x GC-TofMS). Soil and sediment samples were extracted with dichloromethane in an ultrasonic bath and subjected to gel permeation chromatography to eliminate lipids and humic matter. The low molecular weight fraction was then ...
The investigation of naturally volatile and derivatized metabolites in biological tissues by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry...
Next, a model was developed that permitted a systematic investigation of peak shape in fluidic modulation. In the case of a non-focusing modulator for comprehensive two-dimensional gas chromatography, the systematic distortions induced when the modulator loads the second-dimension column give rise to a characteristic peak shape. Depending on the operating conditions this systematic distortion can be the dominant component of the second-dimension elution profiles. Understanding the factors that cause different peak shape observations provides a rugged approach to method development. It is shown that low flow ratio can lead to significant peak skewing and increasing the flow ratio reduces the magnitude of peak skewing. Validation of the peak shape model is made by comparison with experimental data ...
Title: Characterization and Optimization of a High Surface Area-Solid Phase Microextraction Sampler for the Collection of Trace Level Volatile Organic Compounds in the Field Shannon Scott McDonald, Master of Science in Public Health, 2006 Directed By: Gary Hook, CDR, USN Assistant Professor, Department of Preventive Medicine and Biometrics A prototype rapid, high volume air sampling device based on Solid Phase Microextraction (SPME) has been developed for the collection of trace level volatile organic compounds (VOCs). The High Surface Area-Solid Phase Microextraction (HSA- SPME) device contains ten times more polymer than traditional SPME fibers and is uniquely designed to optimize compound uptake at higher flow rates. This study evaluated the extraction efficiency at six air sampling flow rates ranging from 0.1 L/min to 10 L/min and compared total compound extraction at the two extreme flow rates. A 10 ppbv concentration of 39 volatile organic compounds was used. ...
Performed phytochemical study contributes to the knowledge of volatile organic compounds (VOCs) of Halopteris filicina (Grateloup) Kützing, Dictyota dichotoma (Hudson) J. V. Lamouroux, Posidonia oceanica (L.) Delile and Flabellia petiolata (Turra) Nizamuddin from the Adriatic Sea (single point collection). VOCs were investigated by headspace solid-phase microextraction (HS-SPME) and analysed by gas chromatography and mass spectrometry (GC-MS/FID). H. filicina headspace contained dimethyl sulfide (DMS; 12.8%), C8-compounds (e.g. fucoserratene (I; 9.5%)), benzaldehyde (II; 8.7%), alkane C17, dictyopterene D and C (III, IV), tribromomethane (V), 1-iodopentane, others. F. petiolata headspace was characterized by DMS (22.2%), 6-methylhept-5-en-2-one (9.5%), C17 (9.1%), II (6.5%), compounds I-V. DMS (59.3%), C15 (14.5%), C17 (7.2%) and C19 (6.3%) dominated in P. oceanica headspace. Sesquiterpenes were found in D. dichotoma, predominantly germacrene D (28.3%) followed by other cadinenyl (abundant), muurolenyl
Floral volatiles and reward traits are major drivers for the behavior of mutualistic as well as antagonistic flower visitors, i.e., pollinators and florivores. These floral traits differ tremendously between species, but intraspecific differences and their consequences on organism interactions remain largely unknown. Floral volatile compounds, such as terpenoids, function as cues to advertise rewards to pollinators, but should at the same time also repel florivores. The reward composition, e.g., protein and lipid contents in pollen, differs between individuals of distinct plant families. Whether the nutritional value of rewards within the same plant species is linked to their chemotypes, which differ in their pattern of specialized metabolites, has yet not been investigated. In the present study, we compared Tanacetum vulgare plants of five terpenoid chemotypes with regard to flower production, floral headspace volatiles, pollen macronutrient and terpenoid content, and floral attractiveness to
Volatile organic compounds make up a very large group of chemical substances and are often sub-classified by boiling point temperature ranges which gives an idea of how likely it is to be found in liquid, solid, gaseous forms (or possibly more than one state) at various temperatures. The levels found in breathable air and how they affect air quality are strongly correlated with the boiling points. In general, the lower the boiling point, the higher the concentration that will be present in the air.. VVOC (Very Volatile Organic Compounds) Boiling points: less than 0 C to 100 C. VOC (Volatile Organic Compounds) Boiling points: 50 C - 260 C. SVOC (Semi-Volatile Organic Compounds) Boiling points 260 C - 380 C (includes many biocides). POM (Particulate Organic Matter aka Solid Organic Compounds) Boiling points exceeding 380C includes PAHs (polycyclic aromatic hydrocarbon compounds). ...
In order to determine volatile organic compounds (VOC) released from the building and furnishing materials gas chromatography with air samples enrichment on Tenax TA and thermal desorption was used. The results obtained were compared with the results of air samples enrichment on active carbon with carbon disulfide extraction. To the thermal desorption the home made device, a
Volatile organic compounds (VOCs) are small molecules that exhibit high vapor pressure under ambient conditions and have low boiling points. Although VOCs contribute only a small proportion of the total metabolites produced by living organisms, they play an important role in chemical ecology specifically in the biological interactions between organisms and ecosystems. VOCs are also important in the health care field as they are presently used as a biomarker to detect various human diseases. Information on VOCs is scattered in the literature until now; however, there is still no available database describing VOCs and their biological activities. To attain this purpose, we have developed KNApSAcK Metabolite Ecology Database, which contains the information on the relationships between VOCs and their emitting organisms. The KNApSAcK Metabolite Ecology is also linked with the KNApSAcK Core and KNApSAcK Metabolite Activity Database to provide further information on the metabolites and their biological
The pore structure of materials plays a key role in adsorption, and it is of great significance to regulate the porosity of adsorbent for specific adsorbate. Herein, porous carbons (PCs) with engineered porosity were synthesized as adsorbents for volatile organic compounds (VOCs), which employed sucrose-based hydrochar via KOH activation. Surface area of 2604 m2/g together with pore volume of 1.685 cm3/g could be reached when KOH/hydrochar ratio was 3. The adsorption capacities of three typical VOCs were in the order of toluene , acetic ether , acetone, with the vapor pressure had greatest effect on adsorption among the properties of adsorbates. Influence of carbon porosity was further investigated, showing that micropores in the range of 1-3 times of the VOC diameter were crucial to the adsorption process. In addition, more than 90 % of the initial adsorption capacity could be reached after four regeneration cycles. Considering economic and environmental aspects, we demonstrated porous carbons ...
TY - JOUR. T1 - Variation in the specificity of plant volatiles and their use by a specialist and a generalist parasitoid. AU - Gols, R.. AU - Veenemans, C.. AU - Potting, R.P.J.. AU - Smid, H.M.. AU - Dicke, M.. AU - Harvey, J.A.. AU - Bukovinszky, T.. N1 - Reporting year: 2012 Metis note: 5274; WAG; TE; AqE. PY - 2012. Y1 - 2012. N2 - Herbivore-induced plant volatiles (HIPV) provide important information that influences host location behaviour for insect natural enemies, such as parasitoid wasps, that develop in the bodies of herbivorous insects. The dietary breadth of both the parasitoid and its host may affect the extent to which a searching parasitoid relies on HIPV. Specialist species are expected to rely on specific volatile cues to which they respond innately, whereas generalists are expected to show a higher degree of phenotypic plasticity that depends on foraging experience in the parasitoid. We compared the response to HIPV emitted by different plant species damaged by host and ...
Ion mobility spectrometry (IMS) is routinely used in screening checkpoints for the detection of explosives and illicit drugs but it mainly relies on the capture of particles on a swab surface for the detection. Solid phase microextraction (SPME) has been coupled to IMS for the preconcentration of ex …
Many hours of sunlight in the midnight sun period suggest that significant amounts of biogenic volatile organic compounds (BVOCs) may be released from arctic ecosystems during night-time. However, the emissions from these ecosystems are rarely studied and limited to point measurements during daytime. We measured BVOC emissions during 24-hour periods in the field using a push-pull chamber technique and collection of volatiles in adsorbent cartridges followed by analysis with gas chromatography- mass spectrometry. Five different arctic vegetation communities were examined: high arctic heaths dominated by Salix arctica and Cassiope tetragona, low arctic heaths dominated by Salix glauca and Betula nana and a subarctic peatland dominated by the moss Warnstorfia exannulata and the sedge Eriophorum russeolum. We also addressed how climate warming affects the 24-hour emission and how the daytime emissions respond to sudden darkness. The emissions from the high arctic sites were lowest and had a strong diel
Emissions of volatile organic compounds (VOCs) from sunflower (Helianthus annuus L. cv. giganteus) were measured in a continuously stirred tank reactor. The compounds predominantly emitted from sunflo
Under settlements with the Federal Trade Commission, three mattress manufacturers have agreed to stop making unsupported claims that the mattresses they sell are free of harmful volatile organic compounds (VOCs).
Leaf litter, at the interface between the soil and the atmosphere, releases Biogenic Volatile Organic Compounds (BVOC) which play an important role both in global atmospheric chemistry and plant ecology. Litter is especially important in the Mediterranean region, where it is produced in high amounts and decomposes slowly. Only leaf litter emissions of two dominant species (Pinus halepensis and Eucalyptus spp.) present in the Mediterranean region have been studied so far. The aim of this study is to characterize (quantitatively and qualitatively) the BVOC emissions (C10-C15) from litter (freshly fallen and non-decomposed leaves) under laboratory conditions. Sixteen species frequently found in the Mediterranean region were considered, nine of which possess terpene storage structures. Results show a large diversity of BVOC (87 compounds detected, terpenes, alkanes, alkenes, aldehydes, ketones, benzenoids), with terpene emission being higher than non-terpenic emission in most of the cases. Species ...
Considerable amounts and varieties of biogenic volatile organic compounds (BVOCs) are exchanged between vegeta-tion and the surrounding air. These BVOCs play key ecological and atmospheric roles that must be adequately repre-sented for accurately modeling the coupled biosphere-atmosphere-climate earth system. One key uncertainty in existing models is the response of BVOC fluxes to an important global change process: drought. We describe the diur-nal and seasonal variation in isoprene, monoterpene, and methanol fluxes from a temperate forest ecosystem before, during, and after an extreme 2012 drought event in the Ozark region of the central USA. BVOC fluxes were domi-nated by isoprene, which attained high emission rates of up to 35.4 mg m -2h -1 at midday. Methanol fluxes were characterized by net deposition in the morning, changing to a net emission flux through the rest of the daylight hours. Net flux of CO 2 reached its seasonal maximum approximately a month earlier than isoprenoid fluxes, ...
List of Volatile Organic Compound companies, manufacturers and suppliers for the Shipbuilding and Water Transport industry serving New Brunswick on Environmental XPRT
The re-use of sewage sludge without any treatment as primary material-mixed with clays-in order to obtain structural ceramics for buildings has been successfully improved. In the Ecobrick® project, the firing of a mixture of specific percentages of three components (clays, sludges and forest debris) resulted in a lighter and more thermal and acoustic insulating brick, compared with conventional clay-bricks. Volatile organic compounds (VOC) emission from the manufacturing of ceramics is the most important aspect to control. In the Ecobrick® project VOC emissions were monitored by using a bench-scale furnace. The study was conducted using an EPA recommended sampling train and portable sampling tubes that were thermally desorbed and analyzed by gas chromatography/mass spectrometry. Drying of raw sewage-sludge and firing processes were considered separately. In this paper, we present VOC emissions coming from the firing step of the Ecobrick® ...
Closed landfills can be a source of VOC and odorous nuisances to their atmospheric surroundings. A self-designed cylindrical air flux chamber was used to measure VOC surface emissions in a closed industrial landfill located in Cerdanyola del Vallès, Catalonia, Spain. The two main objectives of the study were the evaluation of the performance of the chamber setup in typical measurement conditions and the determination of the emission rates of 60 different VOC from that industrial landfill, generating a valuable database that can be useful in future studies related to industrial landfill management. Triplicate samples were taken in five selected sampling points. VOC were sampled dynamically using multi-sorbent bed tubes (Carbotrap, Carbopack X, Carboxen 569) connected to SKC AirCheck 2000 pumps. The analysis was performed by automatic thermal desorption coupled with a capillary gas chromatograph/mass spectrometry detector. The emission rates of sixty VOC were calculated for each sampling point in ...
TY - JOUR. T1 - Profile of volatile metabolites in urine by gas chromatography-mass spectrometry. AU - Zlatkis, Albert. AU - Bertsch, Wolfgang. AU - Lichtenstein, H. A.. AU - Tishbee, Arye. AU - Shunbo, Farid. AU - Liebich, M.. AU - Coscia, A. M.. AU - Fleischer, N.. PY - 1973. Y1 - 1973. N2 - Profiles of volatile metabolites of 150 urine samples from normal individuals and 40 samples from subjects with diabetes mellitus have been studied by gas chromatography and mass spectrometry. The technique involves adsorption of the urinary headspace volatiles on Tenax GC, heat desorption with helium, trapping on a cooled precolumn, and chromatography on 100-m × 0.50-mm i.d. nickel columns. Individual profiles were observed over a period of 2 months. Characteristic constituents in normal urines are 2-butanone, 2-pentanone, 4-heptanone, dimethyl disulfide, several alkyl furans, pyrrole, and carvone. In subjects with diabetes mellitus under insulin treatment, high concentrations of pyrazines, ...
This study investigated the diel emission of volatile organic compounds (VOCs) from intact apple (Malus x domestica Borkh., cv. Golden Delicious) and grape (Vitis vinifera L., cv. Pinot Noir) foliage. Volatiles were monitored continuously for 48 h by proton transfer reaction - time of flight - mass spectrometry (PTRToF-MS). In addition, volatiles were collected by closed-loop-stripping-analysis (CLSA) and characterized by gas chromatography-mass spectrometry (GC-MS) after 1 h and again 24 and 48 h later. Fourteen and ten volatiles were characterized by GC-MS in apple and grape, respectively. The majority of these were terpenes, followed by green leaf volatiles, and aromatic compounds. The PTR-ToF-MS identified 10 additional compounds and established their diel emission rhythms. The most abundant volatiles displaying a diel rhythm included methanol and dimethyl sulfide in both plants, acetone in grape, and mono-, homo- and sesquiterpenes in apple. The majority of volatiles were released from both ...
Savareear, Benjamin, Jacobs, Matthew R and Shellie, Robert A 2014, Multiplexed dual first-dimension comprehensive two-dimensional gas chromatography-mass spectrometry with contra-directional thermal modulation, Journal of Chromatography A, vol. 1365, pp. 183-190, doi: 10.1016/j.chroma.2014.09.014. ...
We apply a high-resolution chemical transport model (GEOS-Chem CTM) with updated treatment of volatile organic compounds (VOCs) and a comprehensive suite of airborne datasets over North America to (i) characterize the VOC budget and (ii) test the ability of current models to capture the distribution and reactivity of atmospheric VOCs over this region. Biogenic emissions dominate the North American VOC budget in the model, accounting for 70 % and 95 % of annually emitted VOC carbon and reactivity, respectively. Based on current inventories anthropogenic emissions have declined to the point where biogenic emissions are the dominant summertime source of VOC reactivity even in most major North American cities. Methane oxidation is a 2× larger source of nonmethane VOCs (via production of formaldehyde and methyl hydroperoxide) over North America in the model than are anthropogenic emissions. However, anthropogenic VOCs account for over half of the ambient VOC loading over the majority of the region owing to
Hot Water Treatment and Steam Flushing/Stripping. Description. This process injects hot water and steam into an aquifer to mobilize volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs). Vapors rise to the near-surface soil where they are removed by vacuum extraction and then treated. Similar to Enhanced Soil Vapor Extraction and Dynamic Underground Stripping in many ways, hot water treatment entails the injection of hot water into the subsurface to mobilize coal tars. The hot water is injected at the perimeter of the tar formation and withdrawn from the center of the formation. In this way, the site is hydraulically isolated. Tar is mobilized by the hot water and flows to the recovery wells, where it is removed from the subsurface along with the hot water. Maintaining a cold water cap over the area can control volatilization of the lighter tar constituents. Any volatile organics condense once they reach the cold water. At the surface, the water is separated from the coal ...
The U.S. Environmental Protection Agency (EPA) has added 128 substances to the list of chemicals sometimes found in aerosol paints that emit volatile organic compounds (VOCs). The primary substances include formaldehyde, ethanol, benzene, propane and vinyl chloride. VOCs react with nitrogen oxides in the presence of sunlight to form ground-level ozone, which has been linked to respiratory ailments. Spray paint manufacturers must now determine whether their products contain the newly-added substances and still comply with aerosol coating emissions limits. Starting in January 2009, the EPA began limiting VOC emissions from aerosols such as spray paints, primers and clear coatings. The EPA rule, issued in 2007, is similar to a California standard and applies to manufacturers and distributors of aerosol products which are used for both industrial applications and by do-it-yourselfers. The rule focuses on encouraging manufacturers to use less reactive VOC ingredients in their product formulas since ...
In this work, the volatile profiles of smoked and non-smoked Iranian rice were identified, and their relative abundance was calculated and compared. Headspace solid-phase microextraction together with gas chromatography-mass spectrometry (SPME-GC-MS) were used to extract and identify the volatile compounds. The main groups of volatiles in Iranian rice were aldehydes, ketones, phenol derivatives, furans, linear hydrocarbons, esters and terpenes. The chemical family aldehydes was the most abundant one in the profile of non-smoked rice, while phenol derivatives and furans predominated in smoked samples. This study is the first one reporting comparative data of volatile compounds between smoked and non-smoked Iranian rice.
I am a PDRA in AstrobiologyOU looking at finding evidence of potential life on icy moons using volatile organic compounds (VOCs).. My background is one of variation! I started my career in Osteopathic Medicine which has involved treating patients in both private clinics and the NHS, as well as working with a sporting teams to provide medical care, and teaching a sports massage and rehabilitation diploma. During this time, I decided to expand my knowledge even further (because obviously I didnt have enough to do already!) by enrolling on a part time research MSc degree.. I completed my MSc at Cranfield University in Medical Diagnostics and then moved to the Open University (OU) to complete my PhD Use of Volatile Organic Compound (VOC) Profiling in Investigating Diseases of the Gut and Diet Related Conditions. This is where my introduction to VOCs blossomed, and I developed skills in thermal desorption (TD), gas chromatography mass spectrometry (GC-MS), and selective ion flow tube mass ...
The fine particles serving as cloud condensation nuclei in pristine Amazonian rainforest air consist mostly of secondary organic aerosol. Their origin is enigmatic, however, because new particle formation in the atmosphere is not observed. Here, we show that the growth of organic aerosol particles can be initiated by potassium-salt-rich particles emitted by biota in the rainforest. These particles act as seeds for the condensation of low- or semi-volatile organic compounds from the atmospheric gas phase or multiphase oxidation of isoprene and terpenes. Our findings suggest that the primary emission of biogenic salt particles directly influences the number concentration of cloud condensation nuclei and affects the microphysics of cloud formation and precipitation over the rainforest.. ...
Recent findings suggest an association between exposure to cleaning products and respiratory dysfunctions including asthma. However, little information is available about quantitative airborne exposures of professional cleaners to volatile organic compounds deriving from cleaning products. During the first phases of the study, a systematic review of cleaning products was performed. Safety data sheets were reviewed to assess the most frequently added volatile organic compounds. It was found that professional cleaning products are complex mixtures of different components (compounds in cleaning products: 3.5 ± 2.8), and more than 130 chemical substances listed in the safety data sheets were identified in 105 products. The main groups of chemicals were fragrances, glycol ethers, surfactants, solvents; and to a lesser extent phosphates, salts, detergents, pH-stabilizers, acids, and bases. Up to 75% of products contained irritant (Xi), 64% harmful (Xn) and 28% corrosive (C) labeled substance
Determination of volatile organic compounds (VOCs) in ambient air using a sampling and analytical method of tenax-TA/Carbotrap resin adsorption, thermal desorption procedure and gas chromatograph/mass ...
Headspace (HS), Solid Phase Microextraction of Headspace (HS-SPME) or Split/Splitless Injection (SSI) are viable techniques and have advantages and disadvantages. While SPME can be performed by either direct immersion with the sample or headspace sampling, HS-SPME is considered the most effective technique since this approach eliminates the complex oil matrix. Likewise, conventional HS also targets volatiles that include the terpenes, leaving the high molecular weight oils and cannabinoids behind (Figure 1). SSI eliminates the complexity of a HS or SPME concentrator/autosampler, however, sensitivity and column lifetime become limiting factors to high throughput, since the entire sample is introduced to the inlet and ultimately the column.. The GC capillary columns range from thicker film, mid-polarity (Rxi-624sil MS for instance) to thinner film, non-polar 100% polysiloxane-based phases, such as an Rxi-1ms. A thicker film provides the best resolution among the highly volatile, early eluting ...
The individual, together with its environment, has been reported as the main force driving composition and structure of skin microbiota in healthy dogs. Therefore, one of the major concerns when analyzing canine skin microbiota is the likely influence of the environment. Despite the dense fur covering, certain skin diseases exhibit differential prevalence among skin sites, dog breeds, and individuals. We have characterized the normal variability of dog skin microbiota in a well-controlled cohort of a large number of Golden-Labrador Retriever crossed dogs (N = 35) with similar ages, related genetic background, and a shared environment. We found that the individual drives the skin microbiota composition and structure followed by the skin site. The main bacterial classes inhabiting dog skin in this cohort are Gammaproteobacteria and Bacilli. We also detected bacteria associated to the environment on different dog skin sites that could be reflecting the different degrees of exposure of each skin site and
Citation: Parker, D.B., Cai, L., Olsen, M. 2011. Reduction of odorous VOC in phenolic solutions and swine manure slurry using soybean peroxidase and peroxides [abstract]. In: Proceedings 242nd American Chemical Society National Meeting, Denver, CO; Aug. 28-Sept. 1, 2011. Abstract no. 248. Interpretive Summary: Technical Abstract: A research project was conducted to evaluate the efficacy of low-activity soybean peroxidase (SBP; 0.75 U/mg) and H2O2 for reducing emissions of odorous volatile organic compounds (VOC) from standard solutions (phenol and 4-methylphenol; 1 mM each) and swine manure slurry. VOC emissions were measured in a small wind tunnel. Air samples were collected in stainless steel sorbent tubes and analyzed by GC/MS. SBP (2000 mg/L) reduced 4-methylphenol and phenol emissions in standard solutions by 99 and 50%, respectively. The optimum H2O2 addition was 1.32 mM per mM phenolic substrate. Percent reduction of 4-methylphenol emission was about 65% in swine slurry with SBP addition ...
In the final experimental section, the IGC methodology was applied to a commercially available MOF, ZIF-8, with greatly different geometric and chemical properties from the other MOFs. A molecular-sieving effect was observed preventing the adsorption of branched-alkanes, aromatics, and heavily halogenated compounds. Hydrogen-bonding interactions were found to be important for the adsorption of alcohols and amines. However, the adsorption of hydrogen-bond bases was found to be greatly lessened from that of the other MOFs. Thermodynamics of adsorption for the organic compounds studied were calculated to be significantly reduced from IRMOF-1 and the polarizability was used to calculate the specific component of free energy. The specific component of the free energy was found to correlate well to the dipole moment of the adsorbed species. In addition, significant enhancement was seen in the adsorption of ethylene and propylene over their respective alkanes and this was attributed to a strong ...
Crude oil is a generic term for the unrefined flammable liquid that is mined from the ground. It is an extremely varied and very complex medium that can contain many thousands of organic compounds, whose contents and concentrations vary enormously from one sample to another. This article discusses how recent advances in time-of-flight-mass spectrometry coupled with comprehensive two-dimensional gas chromatography is helping the petrochemical industry to characterize crude oils more fully and so provide solutions to common problems experienced during drilling, extraction, and refining.
You may also wish to search for items by Sharpe. 2 matching references were found. Dickinson, E.; Sharpe, K.; Simkins, A.W.; Teoh, G.E., Thermodynamics of glycerol trioleate + n-alkanes, J. Chem. Soc., Faraday Trans. 1, 1981, 77, 1987-90. [all data] Seeley, J.V.; Kramp, F.J.; Sharpe, K.S.; Seeley, S.K., Characterization of gaseous mixtures of organic compounds with dual-secondary column comprehensive two-dimensional gas chromatography (GCx2GC), J. Sep. Sci., 2002, 25, 1-2, 53-59, https://doi.org/10.1002/1615-9314(20020101)25:1/2,53::AID-JSSC53,3.0.CO;2-V . [all data] ...
Chronic pulmonary infections are the principal cause of morbidity and mortality in individuals with cystic fibrosis (CF). Due to the polymicrobial nature of these infections, the identification of the particular bacterial species responsible is an essential step in diagnosis and treatment. Current diagnostic procedures are time-consuming, and can also be expensive, invasive and unpleasant in the absence of spontaneously expectorated sputum. The development of a rapid, non-invasive methodology capable of diagnosing and monitoring early bacterial infection is desired. Future visions of real-time, in situ diagnosis via exhaled breath testing rely on the differentiation of bacteria based on their volatile metabolites. The objective of this proof-of-concept study was to investigate whether a range of CF-associated bacterial species (i.e. Pseudomonas aeruginosa, Burkholderia cenocepacia, Haemophilus influenzae, Stenotrophomonas maltophilia, Streptococcus pneumoniae and Streptococcus milleri) could be ...
Methods Patients were recruited from outpatients with proven Crohns disease(CD N = 41), ulcerative colitis(UC N = 49), IBS(N = 30) and healthy volunteers(N = 47). Disease activity was recorded using Harvey-Bradshaw index(HBI) in CD and simple clinical colitis activity index(SCCAI) in UC. Faecal headspace gas was sampled with SPME and transferred to GC-MS for VOC identification. Statistical analysis was performed on presence or absence and peak area of VOCs.. ...
The Wärtsilä Voyage Emissions Reduction (VER) system is a means for increasing oil tanker revenues, while also significantly aiding the environment through reduced emissions. The system effectively eliminates the problem of volatile organic compound (VOC) emissions from tankers during laden voyages.
Citation: Hoh, E., Lehotay, S.J., Mastovska, K., Ngo, H., Vetter, W., Pangallo, K., Reddy, C. 2009. Simultaneous quantitation of multiple classes of organohalogen compounds in fish oils with direct sample introduction comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry. Journal of Agricultural and Food Chemistry. 57(7):2653-2660. Interpretive Summary: Persistent organic pollutants (POPs) have accumulated and biomagnified in the environmnent and animals (including humans) for many years. They are being studied and monitored by many organizations worldwide for scientific and regulatory purposes. The presence of these contaminants, including naturally occurring halogenated compounds (NHCs) having physico/chemical properties similar to POPs, is a food safety concern, especially in food supplements marketed for improved health. New analytical methods are needed to more efficiently and effectively detect these kinds of chemicals in foods, such as fish oil supplements. ...
This list contains a non-exhaustive inventory of substances taken from: (1) Table 3 of Annex VI to CLP; (2) the Candidate List of SVHCs; (3) Annex XIV of REACH (Authorisation List); (4) Annex XVII of REACH (Restrictions List); (5) F-gases subject to emission limits/reporting per Regulation 517/2014/EU; and (6) volatile organic compounds (VOCs) listed in the Ambient Air Directive 2008/50/EC. The basis of the list is Annex I(3) of the Construction Products Regulation 305/2011/EC, which stipulates that construction works must not have a high impact on human health or the environment as a result of: giving off toxic gas; emissions of dangerous substances, volatile organic compounds (VOC), greenhouse gases or dangerous particles into indoor or outdoor air; release of dangerous substances into drinking water, ground water, marine waters, surface waters or soil.. ...
This list contains a non-exhaustive inventory of substances taken from: (1) Table 3 of Annex VI to CLP; (2) the Candidate List of SVHCs; (3) Annex XIV of REACH (Authorisation List); (4) Annex XVII of REACH (Restrictions List); (5) F-gases subject to emission limits/reporting per Regulation 517/2014/EU; and (6) volatile organic compounds (VOCs) listed in the Ambient Air Directive 2008/50/EC. The basis of the list is Annex I(3) of the Construction Products Regulation 305/2011/EC, which stipulates that construction works must not have a high impact on human health or the environment as a result of: giving off toxic gas; emissions of dangerous substances, volatile organic compounds (VOC), greenhouse gases or dangerous particles into indoor or outdoor air; release of dangerous substances into drinking water, ground water, marine waters, surface waters or soil.. ...
This list contains a non-exhaustive inventory of substances taken from: (1) Table 3 of Annex VI to CLP; (2) the Candidate List of SVHCs; (3) Annex XIV of REACH (Authorisation List); (4) Annex XVII of REACH (Restrictions List); (5) F-gases subject to emission limits/reporting per Regulation 517/2014/EU; and (6) volatile organic compounds (VOCs) listed in the Ambient Air Directive 2008/50/EC. The basis of the list is Annex I(3) of the Construction Products Regulation 305/2011/EC, which stipulates that construction works must not have a high impact on human health or the environment as a result of: giving off toxic gas; emissions of dangerous substances, volatile organic compounds (VOC), greenhouse gases or dangerous particles into indoor or outdoor air; release of dangerous substances into drinking water, ground water, marine waters, surface waters or soil.. ...