Volatile organic compound sampling

Karbiwnyk, C. M., Mills, C. S., Helmig, D., and Birks, J. W., Use of chlorofluorocarbons as internal standards for the measurement of atmospheric nonmethane volatile organic compounds sampled onto solid adsorbent cartridges. Environ. Sci. TechnoL, 37, 1002-1007, 2003. 

Automated analyzers may be used for continuous monitoring of ambient poUutants and EPA has developed continuous procedures (23) as alternatives to the referenced methods. Eor source sampling, EPA has specified extractive sampling trains and analytical methods for poUutants such as SO2 and SO [7446-11-9] sulfuric acid [7664-93-9] mists, NO, mercury [7439-97-6], beryUium [7440-41-7], vinyl chloride, and VOCs (volatile organic compounds). Some EPA New Source Performance Standards requite continuous monitors on specified sources. 

Method 25 applies to the measurement of volatile organic compounds (VOC) as nonmethane organics (TGNMO), reported as carbon. Organic particulate matter will interfere with the analysis, and, therefore, in some cases, an in-stack particulate filter will be required. The method requires an emission sample to be withdrawn at a con-... 

At the Taylor Road landfill (originally intended for the disposal of municipal refuse only), unknown quantities of hazardous wastes from industrial and residential sources were deposited. During the period when the landfill was active, soil and groundwater samples collected at the site were found to contain concentrations of volatile organic compounds and metals above acceptable safe drinking water standards. Analysis of samples collected from private drinking water wells indicated that contamination... 

Contractors at Sites B, D, G, I, and J had incomplete sampling practices and as a result were not able to evaluate PPE levels based on monitoring data. Eor example, both contractors SSAHPs at Site I lacked provisions for monitoring site hazards such as metals, pesticides, herbicides, and semi-volatile organic compounds (SVOCs) that could not be evaluated with a PID. Since worker exposures to the range of hazards on site had not been characterized, PPE was not selected based on its performance relative to the nature and level of site hazards. 

Self-Test 4.11A The oil produced from eucalyptus leaves contains the volatile organic compound eucalyptol. At 190.°C and 60.0 Torr, a sample of eucalyptol vapor had a density of 0.320 g-L . Calculate the molar mass of eucalyptol. 

Nilsson, T, Ferrari, R., and Facchetti, S., Interlaboratory Studies for the Validation of Solid-phase Mieroextraction for the Quantitative Analysis of Volatile Organic Compounds in Aqueous Samples, Anu/yrica Chimica Acta 356, 1997, 113-123. 

As part of the Third National Health and Nutrition Evaluation Survey (NHANES 111), the Environmental Health Laboratory Sciences Division of the National Center for Environmental Health, Centers for Disease Control, will be analyzing human blood samples for trichloroethylene and other volatile organic compounds. These data will give an indication of the frequency of occurrence and background levels of these compounds in the general population. 

Headspace analysis has also been used to determine trichloroethylene in water samples. High accuracy and excellent precision were reported when GC/ECD was used to analyze headspace gases over water (Dietz and Singley 1979). Direct injection of water into a portable GC suitable for field use employed an ultraviolet detector (Motwani et al. 1986). While detection was comparable to the more common methods (low ppb), recovery was very low. Solid waste leachates from sanitary landfills have been analyzed for trichloroethylene and other volatile organic compounds (Schultz and Kjeldsen 1986). Detection limits for the procedure, which involves extraction with pentane followed by GC/MS analysis, are in the low-ppb and low-ppm ranges for concentrated and unconcentrated samples, respectively. Accuracy and precision data were not reported. 

This is a relatively new technique that is used for PCBs and other nonpolar, volatile and semi-volatile organic compounds. Typically, a small aliquot of soil sample (0.5-20 g) is used for the extraction. Soil samples are extracted with one or more organic solvents using microwave energy at elevated temperature (100-115 °C) and pressure (50-175 psi). This method uses less solvent and takes significantly less time than Soxhlet extraction but is limited to thermally stable compounds. 

For the charcoal, XAD, and PUF adsorbents discussed above, solvent extraction techniques have been developed for the removal and concentration of trapped analytes. Although thermal desorption has been used with Tenax-GC in some specialized air sampling situations [primarily with sampling volatile organic compounds (EPA, Method TO-17 )], this approach is not a viable alternative to solvent extraction for the charcoal, XAD, and PUF adsorbents. The polystyrene and PUF adsorbents are thermally unstable and the charcoal chemisorption bonding is more easily broken by... 

Distillation is a suitable technique for the isolation of volatile organic compounds from liquid samples or the soluble portion of solid samples [24,27-30]. The physical basis of separation depends on the distribution of constituents between the liquid mixture and the vapor in equilibrium with that mixture. The more volatile constituents are concentrated in the vapor phase, which is collected after condensation. The effectiveness of the separation is dependent on the physical properties of the... 

EPA SW-846 Method 8265, Volatile Organic Compounds in Water, Soil, Soil Gas, and Air by Direct Sampling Ion Trap Mass Spectrometry. Electronic version of EPA SW-846 Manual available at http //www.epa.gov/epaoswer/hazwaste/test/ new-meth.htm 8265. 

Blood samples for analysis of volatile organic compounds (VOCs) including hexachloroethane should be collected into containers from which VOC contamination has been reduced (Ashley et al. 1992). Potassium oxalate/sodium fluoride is the recommended anti-coagulant. Blood samples should be placed on ice or refrigerated shortly after collection, and Ashley et al. (1992) recommend that analysis for VOCs be completed within 14 days. 

Ashley DL, Bonin MA, Cardinali FL. 1992. Determining volatile organic compounds in human blood from a large sample population by using purge and trap gas chromatography/mass spectrometry. Anal Chem 64 1021-1029. 

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