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Environ Monit Assess

Title:		Influence of relative humidity and ozone on the sampling of volatile organic compounds on carbotrap/carbosieve adsorbents
Author(s):		Palluau F; Mirabel P; Millet M;
Address:		"Laboratoire de Physico-Chimie de l'Atmosphere, Centre de Geochimie de la Surface (UMR 7517 CNRS-Universite Louis Pasteur), 1, rue Blessig, F-67084, Strasbourg Cedex, France"
Journal Title:		Environ Monit Assess
Year:		2007
Volume:		20060805
Issue:		1-Mar
Page Number:		177 - 187
DOI:		10.1007/s10661-006-9272-z
ISSN/ISBN:		0167-6369 (Print) 0167-6369 (Linking)
Abstract:		"By using a dynamic dilution system, the atmospheric measurement of 11 selected toxics VOCs (ethylene, acetylene, propene, 1-butene, 1,3-butadiene, 1-pentene, 1-hexene, benzene, toluene, ethylbenzene, m+p-xylene) from the list WHO of 1996 and TO-14 method of US EPA by preconcentration by thermal desorption (TD), analysis by gas chromatography (GC), identification and quantification with a flame ionisation detector (FID) was developed and validated in term of metrology, especially the techniques of sampling of these VOCs with adsorbents cartridges 'Air Toxics' when used with an 'UMEG sampler' equipped in the inlet with a nafion membrane. In particular the influence of climatic conditions (temperature and relative humidity) and the influence of chemical factors like ozone, on the representativity of sampling were studied. Experiments made with various humidities showed that the addition of a nafion membrane in the inlet of the sampling system was required. Without this membrane, losses of compounds were observed for RH >50%. With this membrane, storage for 2 weeks in a refrigerator, as for canisters, did not induce a loss of compounds. No significative decrease of concentrations of the studied VOCs after 14 days storage, which are known to react with ozone, were observed with an ozone concentrations of 55 ppb. One explanation is that nafion membrane, placed in the inlet of the sampler, will neutralize ozone before entering the sampling tubes. This observation is in accordance with literature which states that the sampling of VOCs on Carbotrap cartridges without ozone scrubber induce a loss of compounds"
Keywords:		Adsorption Air Pollutants/*analysis Environmental Monitoring/instrumentation/methods France *Humidity Organic Chemicals/*analysis *Ozone;
Notes:		"MedlinePalluau, Fabienne Mirabel, Philippe Millet, Maurice eng Research Support, Non-U.S. Gov't Netherlands 2006/08/10 Environ Monit Assess. 2007 Apr; 127(1-3):177-87. doi: 10.1007/s10661-006-9272-z. Epub 2006 Aug 5"