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Scientific Articles - PTR-MS Bibliography

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Found 4 results
Title [ Year(Asc)]
Filters: Author is Custer, Thomas G  [Clear All Filters]
[Ngwabie2008] Ngwabie, N. Martin, G. W. Schade, T. G. Custer, S. Linke, and T. Hinz, "Abundances and flux estimates of volatile organic compounds from a dairy cowshed in Germany", Journal of environmental quality, vol. 37, no. 2: American Society of Agronomy, Crop Science Society of America, Soil Science Society, pp. 565–573, 2008.
Animal husbandry and manure treatment have been specifically documented as significant sources of methane, ammonia, nitrous oxide, and particulate matter. Although volatile organic compounds (VOCs) are also produced, much less information exists concerning their impact. We report on chemical ionization mass spectrometry and photo-acoustic spectroscopy measurements of mixing ratios of VOCs over a 2-wk measurement period in a large cowshed at the Federal Agricultural Research Centre (FAL) in Mariensee, Germany. The high time resolution of these measurements enables insight into the sources of the emissions in a typical livestock management setting. During feeding hours and solid manure removal, large mixing ratio spikes of several VOCs were observed and correlated with simultaneous methane, carbon dioxide, and ammonia level enhancements. The subsequent decay of cowshed concentration due to passive cowshed ventilation was used to model emission rates, which were dominated by ethanol and acetic acid, followed by methanol. Correlations of VOC mixing ratios with methane or ammonia were also used to calculate cowshed emission factors and to estimate potential nationwide VOC emissions from dairy cows. The results ranged from around 0.1 Gg carbon per year (1 Gg = 109 g) for nonanal and dimethylsulfide, several Gg carbon per year for volatile fatty acids and methanol, to over 10 Gg carbon per year of emitted ethanol. While some estimates were not consistent between the two extrapolation methods, the results indicate that animal husbandry VOC emissions are dominated by oxygenated compounds and may be a nationally but not globally significant emission to the atmosphere.
[Schade2004] Schade, G. W., and T. G. Custer, "OVOC emissions from agricultural soil in northern Germany during the 2003 European heat wave", Atmospheric Environment, vol. 38, no. 36: Elsevier, pp. 6105–6114, 2004.
Fluxes of methanol and acetone were measured from an agricultural field plot during one of the hottest weeks of the heat wave of the summer of 2003 in Europe. Significant positive fluxes from the bare, plowed soil for these oxygenated volatile organic compounds were found. Methanol fluxes ranged from 0 to 0.20 mg C m−2 h−1 while acetone fluxes ranged from −0.01 to 0.05. Mixing ratios for both methanol and acetone showed significant increases at night, consistent with a ground-based emission source for both the compounds. Methanol emissions were well correlated with sensible heat flux, peaking around noon. Assuming abiological production from soil organic matter in the topsoil, we calculate that 48 kJ mol−1 of energy is required to liberate the methanol from the topsoil. In contrast to methanol, acetone fluxes were not correlated with any measured meteorological parameter. This suggests that acetone has another source and may be produced in the soil subsurface, possibly through biological or moisture-driven processes. Using the flux data, we also simulated relaxed eddy accumulation (REA) experiments and reconfirm that sonic temperature can be used to calculate b-factors for REA analysis of a variety of trace gas fluxes.
[DeGouw2000] De Gouw, J. A., C. J. Howard, T. G. Custer, B. M. Baker, and R. Fall, "Proton-transfer chemical-ionization mass spectrometry allows real-time analysis of volatile organic compounds released from cutting and drying of crops", Environmental science & technology, vol. 34, no. 12: ACS Publications, pp. 2640–2648, 2000.
The wounding and drying of plant material during crop harvest could be a significant source of volatile organic compounds (VOCs) that enter the atmosphere. Here, we show that these primarily oxygenated VOCs can be measured using proton-transfer chemical-ionization mass spectrometry (PT-CIMS), a method that allows online and simultaneous monitoring of oxygenated VOC levels. For clover, alfalfa, and corn, leaf wounding and in particular drying were shown to lead to strongly enhanced emissions of a series of C6 aldehydes, alcohols, and esters derived from (Z)-3-hexenal. Additionally, for the forage crops clover and alfalfa, enhanced emissions of methanol, acetaldehyde, acetone, and butanone were observed. The identities of the measured carbonyl compounds were confirmed using high-pressure liquid chromatography. For clover, initial cutting led to a VOC release of about 175 μg of C (g dry wt)-1, while during drying the cut clover released >1000 μg of C (g dry wt)-1; qualitatively, similar amounts of VOCs were released from alfalfa, the major hay crop in the United States. The atmospheric implications of these findings may include effects on the local air quality in agricultural areas, contributions to long-range transport of pollutants, and effects on the formation of HOx (=OH + HO2) radicals in the upper troposphere.
[Gouw1999] De Gouw, J. A., C. J. Howard, T. G. Custer, and R. Fall, "Emissions of volatile organic compounds from cut grass and clover are enhanced during the drying process", Geophysical Research Letters, vol. 26, no. 7: American Geophysical Union, pp. 811–814, 1999.

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Selected PTR-MS related Reviews

F. Biasioli, C. Yeretzian, F. Gasperi, T. D. Märk: PTR-MS monitoring of VOCs and BVOCs in food science and technology, Trends in Analytical Chemistry 30 (7) (2011).

J. de Gouw, C. Warneke, T. Karl, G. Eerdekens, C. van der Veen, R. Fall: Measurement of Volatile Organic Compounds in the Earth's Atmosphere using Proton-Transfer-Reaction Mass Spectrometry. Mass Spectrometry Reviews, 26 (2007), 223-257.

W. Lindinger, A. Hansel, A. Jordan: Proton-transfer-reaction mass spectrometry (PTR–MS): on-line monitoring of volatile organic compounds at pptv levels, Chem. Soc. Rev. 27 (1998), 347-375.


Lists with PTR-MS relevant publications of the University of Innsbruck can be found here: Atmospheric and indoor air chemistry, IMR, Environmental Physics and Nano-Bio-Physics


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