title: Photosensitized degradation kinetics of trace halogenated contaminants in natural waters using membrane introduction mass spectrometry as an in situ reaction monitor.
abstract: The photochemically mediated dechlorination of polyhalogenated compounds represents a potential decontamination strategy and a relevant environmental process in chemically reducing media. We report the UV irradiation of natural and artificial waters containing natural dissolved organic matter to effect the photo-sensitized degradation of chlorinated organic compounds, including tetrachloromethane, 1,1,1-tricloroethane, perchloroethene, 1,2-dibromo-3-chloropropane and chlorobenzene at trace (ppb) levels in aqueous solution. The degradation kinetics are followed in situ using membrane introduction mass spectrometry. By re-circulating the reaction mixture in a closed loop configuration over a semi-permeable hollow fiber polydimethylsiloxane membrane in a flow cell interface, volatile and semi-volatile compounds are continuously monitored using a quadrupole ion trap mass spectrometer. The time resolved quantitative information provides useful mechanistic insights, including kinetic data. Pseudo first-order rate constants for the degradation of contaminant mixtures in natural waters are reported.
authors.affiliation: Applied Environmental Research Laboratories, Department of Chemistry, Vancouver Island University, 900 Fifth Street, Nanaimo, BC V9R 5S5, Canada. Erik.Krogh@viu.ca and University of Victoria, Department of Chemistry, PO Box 3065, Stn CSC, Victoria, BC V8W 3V6, Canada.
authors.forename: Dane R
authors.initials: DR
authors.lastname: Letourneau
authors.affiliation: Applied Environmental Research Laboratories, Department of Chemistry, Vancouver Island University, 900 Fifth Street, Nanaimo, BC V9R 5S5, Canada. Erik.Krogh@viu.ca and University of Victoria, Department of Chemistry, PO Box 3065, Stn CSC, Victoria, BC V8W 3V6, Canada.
authors.forename: Chris G
authors.initials: CG
authors.lastname: Gill
authors.affiliation: Applied Environmental Research Laboratories, Department of Chemistry, Vancouver Island University, 900 Fifth Street, Nanaimo, BC V9R 5S5, Canada. Erik.Krogh@viu.ca and University of Victoria, Department of Chemistry, PO Box 3065, Stn CSC, Victoria, BC V8W 3V6, Canada.
authors.forename: Erik T
authors.initials: ET
authors.lastname: Krogh