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PubMed2001

A comprehensive screen for volatile organic compounds in biological fluids.

A headspace gas chromatographic (GC) screen for common volatile organic compounds in biological fluids is reported. Common GC phases, DB-1 and DB-WAX, with split injection provide separation and identification of more than 40 compounds in a single 20-min run. In addition, this method easily accommodates quantitation. The screen detects commonly encountered volatile compounds at levels below 4 mg%. A control mixture, providing qualitative and semiquantitative information, is described. For comparison, elution of the volatiles on a specialty phase, DB-624, is reported. This method is an expansion and modification of a screen that had been used for more than 20 years. During its first year of use, the expanded screen has proven to be advantageous in routine forensic casework.

Automation↗

PubMed2005

Emission of volatile organic compounds (VOC) from tropical plant species in India.

Foliar emission of volatile organic compounds (VOC) from common Indian plant species was measured. Dynamic flow enclosure technique was used and the gas samples were collected onto Tenax-GC/Carboseive cartridges. The Tenax-GC/Carboseive cartridges were attached to the thermal disorber sample injection system and the gas sample was analysed using gas chromatography (GC) with flame ionisation detection (FID). Fifty-one local plant species were screened, out of which 36 species were found to emit VOC (4 high emitter; 28 moderate emitter; and 4 low-emitter), while in the remaining 15 species no VOC emission was detected or the levels of emission were below detection limit (BDL). VOC emission was found to vary from one species to another. There was a marked seasonal and diurnal variation in VOC emission. The minimum and maximum VOC emission values were < 0.1 and 87 microgg(-1) dry leaf h(-1) in Ficus infectoria and Lantana camara respectively. Out of the 51 plant species studied, 13 species are reported here for the first time. Among the nine tree species (which were selected for detailed study), the highest average hourly emission (9.69+/-8.39 microgg(-1) dry leaf) was observed in Eucalyptus species and the minimum in Syzygium jambolanum (1.89+/-2.48 microgg(-1) dry leaf). An attempt has been made to compare VOC emission from different plant species between present study and the literature (tropical and other regions).

Air Pollutants↗

PubMed2003

Sorption of volatile organic compounds on typical carpet fibers.

Measurements of adsorption isotherms for three volatile organic compounds (VOCs) (toluene, 1,2-dichlorobenzene and 1,1,1-trichloroethane) on polyacrylonitrile carpet fibers over the temperature range 25-45 degrees C were carried out in a thermogravimetric analyzer (TGA). Linear isotherms were observed in all cases with values of the Henry coefficient ranging from 0.063 to 0.941 mm. The results of additional experiments carried out in a simple test chamber containing a single source of VOC showed that the carpet fibers acted as a significant sink causing a prolonged elevation of VOC concentration in the air within the chamber. An unsteady-state model is presented, which adequately described the adsorption and desorption phenomena occurring in the test chamber and yielded realistic values of the adsorption and desorption rate constants. There was good agreement between the equilibrium and kinetic constants obtained in the TGA and test chamber experiments.

Adsorption↗

PubMed2004

[Study on the genetic damage in mice induced by the volatile organic compounds of decoration materials].

OBJECTIVE: To study genetic damage of mice caused by the volatile organic compounds (VOC) of decoration materials. METHODS: Fifty-five hotel guest rooms newly decorated within 6 months and 18 hotel guest rooms not decorated within 3 years were selected to determine the concentrations of 6 main VOC (benzene, methylbenzene, dimethylbenzene, ethyl acetate, butyl acetate, formaldehyde) in the air. Mice were exposed to VOC with the concentrations of 5, 10, 20, 40 times respectively as high as those present in the newly decorated rooms in an exposure cabinet for 15 days. DNA damage of peripheral lymphocytes of the mice was determined by single cell gel electrophoresis (SCGE) and bone marrow micronucleus test. RESULTS: The concentrations of benzene, methylbenzene, dimethylbenzene, ethyl acetate, butyl acetate and formaldehyde in the rooms newly decorated within 6 months (6.50, 3.00, 6.70, 41.33, 1.70 and 0.14 mg/m(3) respectively) were significantly higher than those in rooms not decorated within 3 years (0.08, 0.94, 1.38, 0.25, 0.25, 0.01 mg/m(3), P < 0.01). DNA damage rates of peripheral lymphocytes in the concentrations of 10, 20, 40 times of exposure groups were significantly higher than those in the control groups (P < 0.05 or P < 0.01), and the frequencies of micronucleus in the mice exposed to 40 times of concentration was significantly higher than that in control group. CONCLUSION: High concentrations of the volatile organic chemical compounds may cause genetic damage in mice. SCGE test is more sensitive than micronucleus test.

Air Pollutants↗

PubMed2005

A biogenic volatile organic compounds emission inventory for Yunnan Province.

The first detailed inventory for volatile organic compounds (VOC) emissions from vegetation over Yunnan Province, China was presented. The spatially and temporally resolved inventory was developed based on a geographic information system (GIS), remote sensing (RS) data and field measurement data, such as digitized land-use data, normalized difference vegetation index (NDVI) and temperature data from direct real-time measurement. The inventory has a spatial resolution of 5 km x 5 km and a time resolution of 1 h. Urban, agriculture, and natural land-use distributions in Yunnan Province were combined with biomass factors for each land-use category to produce a spatially resolved biomass inventory. A biogenic emission inventory was developed by combining the biomass inventory with hourly emission rates for tree, shrub and ground cover species of the study area. Correcting for environmental factors, including light intensity and temperature, a value of 1.1 x 10(12) gC for total annual biogenic VOC emissions from Yunnan Province, including 6.1 x 10(11) gC for isoprene, 2.1 x 10(11) gC for monoterpenes, and 2.6 x 10(11) gC for OVOC was obtained. The highest VOC emissions occurred in the northwestern, southwestern and north region of Yunnan Province. Some uncertainties were also discussed in this study.

Algorithms↗

PubMed2002

Comparative risk analysis of six volatile organic compounds in California drinking water.

The widespread use and storage of volatile organic compounds (VOCs) in the United States has led to releases of these chemicals into the environment, including groundwater sources of drinking water. Many of these VOCs are commonly found in public drinking water supplies across the nation and are considered by state or federal agencies to be potentially carcinogenic to humans. In this paper, we evaluate the detection frequencies, detected concentrations, and relative cancer risks of six VOCs in drinking water sources in California from 1995 to 2001. We find that during this 7-year period, the most frequently detected VOCs in sampled drinking water sources were chloroform (12-14%), PCE (11-13%), and TCE (10-12%). Detection frequencies in water were lower for 1,1-DCE (3-6%), MTBE (1-3%), and benzene (<1%). Mean detected concentrations were also consistently above California's primary maximum contaminant level for some VOCs, including benzene, PCE, and TCE. Although none of the six VOCs necessarily poses a significant public health threat from drinking water exposures, 1,1-DCE and benzene werefound to pose the greatest cancer risk relative to the other VOCs. However, after adjusting for the occurrence of each VOC in drinking water, chloroform and PCE were found to pose the greatest relative cancer risk. Despite media reports about significant MTBE contamination of drinking watersupplies in California, MTBE detections were infrequent and this chemical was found to pose the least cancer risk relative to the other VOCs.

California↗

PubMed2003

Genotoxic effects of volatile organic compounds in a chemical factory as evaluated by the Tradescantia micronucleus assay and by chemical analysis.

The clastogenic effects of volatile organic compounds in the workplace air of a chemical factory were studied by means of the Tradescantia micronucleus (Trad-MCN) assay and chemical analysis. Sampling was performed at a chemical factory producing PVC film in Cheong-ju, South Korea. Inflorescences of Tradescantia BNL 4430 were placed for 2, 6, and 9 h at the height of 1.40 m at two locations in the workplace and one outdoor of the chemical industry. Air samplings were conducted in the same places and the collected tube samples were analyzed by automatic thermal desorption/gas chromatography/mass spectrometry (ATD/GC/MS). The frequencies of micronuclei in specimens exposed for 2 h in sites 1-3 were 6.13 +/- 0.47, 5.40 +/- 1.60, and 2.93 +/- 0.43 MCN per 100 tetrads, respectively. GC/MS analysis proved the presence of various volatile organic compounds such as trichloroethylene, toluene, ethyl benzene, (m, p, o)-xylene, styrene, 1,3,5-trimethyl benzene, and 1,2,4-trimethyl benzene. Mean values of toluene measured by 2 h sampling in sites 1-3 were 1946.6, 1368.3, and 340.1 microg/m3, respectively. The toluene concentrations in sites 1 and 2 were at least four to six times higher than that in site 3. The micronucleus frequencies increased with exposure time. In addition, there was a correlation between the micronucleus frequencies and toluene concentration in the air (R2 = 0.96). The results of this in situ monitoring proved the applicability of the Trad-MCN assay combined with chemical analysis for monitoring genotoxic chemicals in the work environment.

Air Pollutants, Occupational↗

PubMed1986

Concentrations of 20 volatile organic compounds in the air and drinking water of 350 residents of New Jersey compared with concentrations in their exhaled breath.

Twenty volatile organic compounds were measured in the personal air and drinking water of 350 New Jersey residents in the fall of 1981. Two consecutive 12-hour integrated personal air samples and two tap water samples were collected from each participant. At the end of the 24-hour monitoring period, each participant supplied a sample of exhaled breath. Simultaneous outdoor samples were collected in 100 residential locations in two cities. Eleven compounds were present much of the time in air, but only four (the trihalomethanes) in water; wide ranges of exposures (three to four orders of magnitude) were noted for most compounds. Ten of 11 compounds displayed significant correlations between air exposures and breath concentrations; the 11th (chloroform) was correlated with drinking water exposures. It was concluded that breath measurements are a feasible, cost-effective, and highly sensitive way to determine environmental and occupational exposures to volatile organic compounds.

Air Pollutants↗

PubMed1998

Emission of volatile organic compounds (VOCs) from PVC floor coverings.

In this study 29 PVC floor coverings were tested for emission of vinyl chloride (VC) and other volatile organic compounds (VOCs). A study on the effect of higher temperature on emission of VOCs from newly manufactured PVC flooring was also carried out. The study was conducted in climatic chamber, according to Polish Standard PN-89/Z-04021. GC method was used for analyzing of the compounds emitted. VC was not emitted from any of the floorings tested. Other VOCs were emitted in different concentrations. The influence of temperature on emission was conducted at temperatures of 23 degrees C and 35 degrees C from 2 hrs up to 180 days after introduction of materials in the chamber. The increase of temperature caused increase of total volatile organic compounds (TVOC) emission during 24 hrs of experiment. Then the emission was comparable for both temperatures. After 9 days emission of identified and unidentified compounds (TVOC) showed a rapid decay and stayed on very low level during a few months. The study conducted showed that PVC floorings after 10 days of installation in the room should not be source of indoor air contamination.

Air Pollution, Indoor↗

PubMed2000

Kinetic study of addition of volatile organic compounds to a nitrifying sludge.

The effects of different concentrations of several volatile organic compounds (VOC) such as ethanol, acetate, propionate, and butyrate ranging from 0 to 2000 mg/L as well as a mixture of volatile fatty acids (MVFA) at a 4:1:1 (acetate:propionate:butyrate) ratio on the nitrification rate in batch cultures were studied. The results showed that ethanol and acetate were consumed in a mixotrophic way by the nitrifying sludge. At a concentration of 500 mg/L, the nitrification rate of inhibition was different for each compound in which propionate and butyrate were the most inhibitory. At 2000 mg/L the inhibition was 80% with ethanol and 100% with acetate, propionate, and butyrate. With similar concentrations of MVFA, the inhibition was also similar to that in acetate. The effect of the addition of pulses of MVFA at a ratio of 4:1:1 during 14 h on the performance of the continuous nitrifying process with a hydraulic retention time of 3 d was also studied. No inhibition of the nitrification process was observed with pulses of 750-3000 mg of MVFA/L in the input of the reactor. The results in batch cultures suggest that the different degrees of inhibition of the nitrification process were related to the type of organic matter added. The noninhibitory effect of the organic matter in the continuous cultures on the nitrification efficiency of the nitrifying sludge might be related to the feeding pattern.

Acetates↗

PubMed2003

Evaluation of multiple solid-phase microextraction as a technique to remove the matrix effect in packaging analysis for determination of volatile organic compounds.

Multiple solid-phase microextraction (SPME) is an useful technique for the direct quantification of solid samples removing any matrix effect. The volatile organic compounds formed in the extrusion-coating process of multilayer packaging materials have already been quantified by multiple HS-SPME coupled to gas chromatography (GC)-mass spectrometry (MS) using volatile organic compound (VOC) solutions in hexadecane for calibration. In this article, water is proposed as solvent to prepare the calibration solutions because it provides a shorter calibration time, better linearity, better reproducibility, and lower detection limits than hexadecane. Besides, the extraction of VOCs from aqueous solutions is exhaustive and avoids the extrapolations needed to calculate the total peak areas, as they can be calculated as the sum of the individual areas of each extraction. Finally, it is checked whether the two solvents provide the same mean values for the total peak areas.

Gas Chromatography-Mass Spectrometry↗

PubMed2006

Volatile organic compounds: sampling methods and their worldwide profile in ambient air.

The atmosphere is a particularly difficult analytical system because of the very low levels of substances to be analysed, sharp variations in pollutant levels with time and location, differences in wind, temperature and humidity. This makes the selection of an efficient sampling technique for air analysis a key step to reliable results. Generally, methods for volatile organic compounds sampling include collection of the whole air or preconcentration of samples on adsorbents. All the methods vary from each other according to the sampling technique, type of sorbent, method of extraction and identification technique. In this review paper we discuss various important aspects for sampling of volatile organic compounds by the widely used and advanced sampling methods. Characteristics of various adsorbents used for VOCs sampling are also described. Furthermore, this paper makes an effort to comprehensively review the concentration levels of volatile organic compounds along with the methodology used for analysis, in major cities of the world.

Air Pollutants↗

PubMed2006

The biogenic volatile organic compounds emission inventory in France: application to plant ecosystems in the Berre-Marseilles area (France).

An inventory describing the fluxes of volatile organic compounds (VOCs), isoprene and monoterpenes, and other VOCs (OVOCs) from the biosphere to the atmosphere, has been constructed within the framework of the ESCOMPTE project (fiEld experimentS to COnstrain Models of atmospheric Pollution and Transport of Emissions). The area concerned, located around Berre-Marseilles, is a Mediterranean region frequently subject to high ozone concentrations. The inventory has been developed using a fine scale land use database for the year 1999, forest composition statistics, emission potentials from individual plant species, biomass distribution, temperature and light intensity. The seasonal variations in emission potentials and biomass were also taken into account. Hourly meteorological data for 1999 were calculated from ALADIN data and these were used to predict the hourly isoprene, monoterpene and OVOC fluxes for the area on a 1 kmx1 km spatial grid. Estimates of annual biogenic isoprene, monoterpene and OVOC fluxes for the reference year 1999 were 20.6, 38.9 and 13.3 kt, respectively, Quercus pubescens, Quercus ilex, Pinus halepensis and garrigue vegetation are the dominant emitting species of the area. VOC emissions from vegetation in this region contribute approximately 94% to the NMVOC (non-methane volatile organic compounds) of natural origin and are of the same order of magnitude as NMVOC emissions from anthropogenic sources. These results complete the global ESCOMPTE database needed to make an efficient strategy for tropospheric ozone reduction policy.

Ecosystem↗

PubMed1981

Gas chromatographic--mass spectrometric determination of volatile organic compounds in fish.

A technique has been developed for the determination of volatile organic compounds in fish. The methodology is based on procedures used to determine purgeable organic compounds in water and wastewater. Fish tissue is added to reagent water, cooled in an ice bath, and homogenized with cell disruption using ultrasonic energy. The processed sample is then analyzed by a purge and trap procedure using an impinger-type device at 70 degrees C, with determination of the purged compounds by computerized gas chromatography-mass spectrometry. Both ground fish and cored fish specimens were successfully analyzed by this technique. The overall average recovery for 39 volatile compounds studied was 77% with an average standard deviation of 20%.

Animals↗

PubMed2002

Predicting the emission rate of volatile organic compounds from vinyl flooring.

A model for predicting the rate at which a volatile organic compound (VOC) is emitted from a diffusion-controlled material is validated for three contaminants (n-pentadecane, n-tetradecane, and phenol) found in vinyl flooring (VF). Model parameters are the initial VOC concentration in the material phase (C0), the material/air partition coefficient (K), and the material-phase diffusion coefficient (D). The model was verified by comparing predicted gas-phase concentrations to data obtained during small-scale chamber tests and by comparing predicted material-phase concentrations to those measured at the conclusion of the chamber tests. Chamber tests were conducted with the VF placed top-side-up and bottom-side-up. With the exception of phenol and within the limits of experimental precision, the mass of VOCs recovered in the gas-phase balances the mass emitted from the material phase. The model parameters (C0, K, and D) were measured using procedures completely independent of the chamber test. Gas- and material-phase predictions compare well to the bottom-side-up chamber data. The lower emission rates for the top-side-up orientation may be explained by the presence of a low-permeability surface layer. The sink effect of the stainless steel chamber surface was shown to be negligible.

Air Pollution, Indoor↗

PubMed2005

Solubility of volatile organic compounds in aqueous ammonia solution.

The Ostwald solubility coefficient, L of 17 volatile organic compounds (VOCs) from the gas phase into water and dilute aqueous ammonia solutions was determined by the equilibrium partitioning in closed system-solid phase micro extraction (EPICS-SPME) method at 303 K and at 0-2.5 mol dm(-3) ammonia concentrations. Ammonia increased the solubility of all VOCs nearly linearly, but to a different extent. The difference in the solubility values in aqueous ammonia solutions (Lmix) compared to pure water (L) is explained on the basis of a Linear Solvation Energy Relationship (LSER) equation made applicable for solvent mixtures, logLmix - logL = x((sNH3 - sH2O)pi2H + (aNH3 - aH2O)Sigma2H + (bNH3 - bH2O)Sigmabeta2H + (vNH3 - VH2O)Vx). sNH3 - sH2O, aNH3 - aH2O, bNH3 - bH2O, vNH3 - vH2O are the differences of solvent parameters, x is the mole fraction, pi2H is the solute dipolarity-polarizability, Sigmaalpha2H is the effective hydrogen bond acidity of the solute, Sigmabeta2H is the effective hydrogen bond basicity of the solute and Vx, the McGowan characteristic volume. The most significant term was v, the phase hydrophobicity. The solubility behavior was explained by the change in structure of the aqueous solution: the presence of ammonia reduces the cavity effect. These findings show that the presence of compounds such as ammonia, frequently observed in environmental waters, especially wastewaters, affect the fugacity of VOCs, having consequences for the environmental partitioning of VOCs and having technical consequences towards wastewater treatment technologies.

Ammonia↗

PubMed2006

Spatial and temporal trends of volatile organic compounds (VOC) in a rural area of northern Spain.

Ambient concentrations of volatile organic compounds (VOCs) were measured at 40 rural sampling points in Navarre (northern Spain). Air samples were collected by means of sorbent passive sampling and analyzed by thermal desorption (TD) and gas chromatography/mass-selective detector (GC/MSD). A total of 140 VOCs were identified during the study, which was carried out between May to October 2004 for a total of a 10 biweekly sampling campaigns. Concentrations of benzene, toluene, ethylbenzene, m/p-xylenes, o-xylene (BTEX) and 1,3,5-trimethylbenzene were determined in order to investigate their temporal and spatial distributions. Geostatistical analysis pointed to traffic as the main emission source of these compounds. Supporting this idea, BTEX and nitrogen oxides concentrations were found to be highly significantly correlated (r = 0.495, P = 0.001), whereas a strong negative correlation between BTEX and ozone was also observed (r = -0.355, P = 0.025). The concentrations for the BTEX group were similar to the values that have been previously reported for other rural areas.

Air↗

PubMed2003

Time and space patterns of volatile organic compounds in a sewage treatment plant.

47 regulated and non-regulated volatile organic compounds (VOCs) were characterised by closed-loop stripping analysis (CLSA) and high resolution gas chromatography coupled to mass spectrometry (HRGC/MS) in 28 aqueous samples from 4 sampling points along a sewage treatment plant in Manresa, Catalonia, Spain. A 4 x 2(2) factorial design (16 samples) was first prepared for the sampling, and reinforced with 12 additional samples at the plant influent. The total analyte weighted mean concentration was 232 microg x l(-1) at the plant influent, with a mass flow of 2231 kg x yr(-1). Petroleum solvents and terpenic compounds accounted for 79% of the influent analyte concentration. VOC concentration in influent was clearly higher for most VOCs from 12 to 22 h (high organic load hours), and lower from 24 to 10 h (lower organic load). Differences between time bands were confirmed through t tests. Differences between weekdays and the weekend were not so clear, and could not be confirmed through t tests. VOC concentrations along the plant are discussed. Overall analyte removal in the plant was 89%.

Environmental Monitoring↗