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Environ Toxicol Chem

Title:		A new tool for laboratory studies on volatilization: extension of applicability of the photovolatility chamber
Author(s):		Wolters A; Kromer T; Linnemann V; Schaffer A; Vereecken H;
Address:		"Forschungszentrum Julich, Institute of Chemistry and Dynamics of the Geosphere IV: Agrosphere, 52425 Julich, Germany. a.wolters@fz-juelich.de"
Journal Title:		Environ Toxicol Chem
Year:		2003
Volume:		22
Issue:		4
Page Number:		791 - 797
DOI:
ISSN/ISBN:		0730-7268 (Print) 0730-7268 (Linking)
Abstract:		"Volatilization from soil and plant surfaces after application is an important source of pesticide residues to the atmosphere. The laboratory photovolatility chamber allows the simultaneous measurement of volatilization and photodegradation of 14C-labeled pesticides under controlled climatic conditions. Both continuous air sampling, which quantifies volatile organic compounds and 14CO2 separately, and the detection of surface-located residues allow for a mass balance of radioactivity. The setup of the photovolatility chamber was optimized, and additional sensors were installed to characterize the influence of soil moisture, soil temperature, and evaporation on volatilization. The modified flow profile in the glass dome of the chamber arising from the use of a high-performance metal bellows pump was measured. Diminished air velocity near the soil surface and a wind velocity of 0.2 m/s in 3 cm height allowed the requirements of the German guideline on assessing pesticide volatilization for registration purposes to be fulfilled. Determination of soil moisture profiles of the upper soil layer illustrated that defined water content in the soil up to a depth of 4 cm could be achieved by water saturation of air. Cumulative volatilization of [phenyl-UL-14C]parathion-methyl ranged from 2.4% under dry conditions to 32.9% under moist conditions and revealed the clear dependence of volatilization on the water content in the top layer"
Keywords:		Air/*analysis Air Pollutants/*analysis/*chemistry Carbon Radioisotopes Environmental Monitoring/*instrumentation/*methods Humidity Insecticides/analysis/chemistry Methyl Parathion/analysis/chemistry Nebulizers and Vaporizers Reproducibility of Results Soi;
Notes:		"MedlineWolters, Andre Kromer, Thomas Linnemann, Volker Schaffer, Andreas Vereecken, Harry eng 2003/04/11 Environ Toxicol Chem. 2003 Apr; 22(4):791-7"