« Previous AbstractCharacterisation of aroma volatiles of indigenous alcoholic beverages: burukutu and pito    Next Abstract"Endosulfan affects pheromonal detection and glands in the male red-spotted newt, Notophthalmus viridescens" »

Environ Sci Technol

Title:		Development of a silicone membrane tube equilibrator for measuring partial pressures of volatile organic compounds in natural water
Author(s):		Ooki A; Yokouchi Y;
Address:		"National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-0053, Japan. ooki.atsushi@nies.go.jp"
Journal Title:		Environ Sci Technol
Year:		2008
Volume:		42
Issue:		15
Page Number:		5706 - 5711
DOI:		10.1021/es800912j
ISSN/ISBN:		0013-936X (Print) 0013-936X (Linking)
Abstract:		"Methods for determining volatile organic compounds (VOCs) in water and air are required so that the VOCs' fluxes in water environments can be estimated. We developed a silicone membrane tube equilibrator for collecting gas-phase samples containing VOCs at equilibrium with natural water. The equilibrator consists of six silicone tubes housed in a polyvinyl chloride pipe. Equilibrated air samples collected from the equilibrator were analyzed with an automated preconcentration gas chromatography-mass spectrometry system for hourly measurements of VOC partial pressures. The partial pressures of all the target VOCs reached equilibrium within 1 h in the equilibrator. The system was used to determine VOC partial pressures in Lake Kasumigaura, a shallow eutrophic lake with a high concentration of suspended particulate matter (SPM). Compressed air was used daily to remove SPM deposited on the inner wall of the equilibrator and to maintain the equilibrium conditions for more than a week without the need to shut the system down. CH2Br2, CHCl3, CHBrCl2, CH2BrCl, C2H5I, C2Cl4, CH3I, and CH3Br in the lake were supersaturated with respect to the air, whereas CH3CI was undersaturated. CHCl3 had the highest flux (6.2 nmol m(-2) hr(-1)) during the observation period"
Keywords:		"Automation Environmental Monitoring/instrumentation/*methods Fresh Water/chemistry Gas Chromatography-Mass Spectrometry/instrumentation/*methods Hydrocarbons, Brominated/analysis *Membranes, Artificial Methyl Chloride/analysis Partial Pressure Particulate;"
Notes:		"MedlineOoki, Atsushi Yokouchi, Yoko eng Research Support, Non-U.S. Gov't 2008/08/30 Environ Sci Technol. 2008 Aug 1; 42(15):5706-11. doi: 10.1021/es800912j"