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Environ Sci Process Impacts

Title:		Quantitative passive soil vapor sampling for VOCs--part 1: theory
Author(s):		McAlary T; Wang X; Unger A; Groenevelt H; Gorecki T;
Address:		"Geosyntec Consultants, Inc., 130 Research Lane, #2, Guelph, Ontario N1G 5G3, Canada. tmcalary@geosyntec.com"
Journal Title:		Environ Sci Process Impacts
Year:		2014
Volume:		20140128
Issue:		3
Page Number:		482 - 490
DOI:		10.1039/c3em00652b
ISSN/ISBN:		2050-7895 (Electronic) 2050-7887 (Linking)
Abstract:		"Volatile organic compounds are the primary chemicals of concern at many contaminated sites and soil vapor sampling and analysis is a valuable tool for assessing the nature and extent of contamination. Soil gas samples are typically collected by applying vacuum to a probe in order to collect a whole-gas sample, or by drawing gas through a tube filled with an adsorbent (active sampling). There are challenges associated with flow and vacuum levels in low permeability materials, and leak prevention and detection during active sample collection can be cumbersome. Passive sampling has been available as an alternative to conventional gas sample collection for decades, but quantitative relationships between the mass of chemicals sorbed, the soil vapor concentrations, and the sampling time have not been established. This paper presents transient and steady-state mathematical models of radial vapor diffusion to a drilled hole and considerations for passive sampler sensitivity and practical sampling durations. The results indicate that uptake rates in the range of 0.1 to 1 mL min(-1) will minimize the starvation effect for most soil moisture conditions and provide adequate sensitivity for human health risk assessment with a practical sampling duration. This new knowledge provides a basis for improved passive soil vapour sampler design"
Keywords:		Air Pollutants/*analysis *Environmental Monitoring Soil/*chemistry Soil Pollutants/*analysis Volatile Organic Compounds/*analysis;
Notes:		"MedlineMcAlary, Todd Wang, Xiaomin Unger, Andre Groenevelt, Hester Gorecki, Tadeusz eng Research Support, U.S. Gov't, Non-P.H.S. England 2014/01/29 Environ Sci Process Impacts. 2014 Mar; 16(3):482-90. doi: 10.1039/c3em00652b. Epub 2014 Jan 28"