Grantee Research Project Results
2003 Progress Report: Environmental Photochemistry of Polybrominated Diphenylethers
EPA Grant Number: R830398Title: Environmental Photochemistry of Polybrominated Diphenylethers
Investigators: Jafvert, Chad T. , Xiao, Changhe , Hua, Inez , Bezares-Cruz, Juan , Filley, Timothy
Current Investigators: Jafvert, Chad T. , Hua, Inez , Filley, Timothy
Institution: Purdue University
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 2002 through December 31, 2003
Project Period Covered by this Report: January 1, 2002 through December 31, 2003
Project Amount: $234,586
RFA: Futures Research in Natural Sciences (2001) RFA Text | Recipients Lists
Research Category: Futures , Ecological Indicators/Assessment/Restoration , Land and Waste Management , Hazardous Waste/Remediation
Objective:
The overall goal of this research is to investigate photochemical transformation of several polybrominated diphenylether (PBDE) congeners under conditions of environmental relevance. The specific objectives of this research project are to: (1) examine environmental matrices and media influences on photolytic transformation rates and product distributions of decabromodiphenylether (BDE209); (2) identify organic products by gas chromatography mass spectrometry (GC-MS); (3) conduct experiments of sufficient length to evaluate reaction product mass balances; and (4) test solar photoreactivity of major BDE209 products (tetra- through nona-congeners).
Progress Summary:
Experiments on the photochemical transformation of BDE209 have been conducted in solar light and in light generated with lamps that have emissions centered at 350 nm (± 50 nm). Experiments have been conducted in quartz vessels with BDE209, either dissolved in hexane or solubilized by aqueous humic acids. Decay rates have been determined by quantifying the remaining BDE209 by GC-electron capture detector (ECD) analyses, and reaction products have been determined by ion trap GC-MS. In sunlight and lamplight, BDE209 decays rapidly within minutes, producing intermediate products with successively shorter GC retention times as a function of irradiation times. The quantum yield for decay in hexane in solar light has been determined. Retention times and mass spectra were compared to those of the standards obtained from Cambridge Isotope Laboratories and Wellington Laboratories. After 6.1 hours of solar irradiation on July 2, 2003, 3 (of 3) nona's, 6 (of 12) octa's, 5 (of 24) hepta's, 11 (of 42) hexa's, 8 (of 46) penta's, 6 (of 42) tetra's, and 3 (of 24) tri's were identified by confirming molecular weight (mass) of the parent ion. Products-intermediates with identical retention times as standards and similar mass spectra include: BDE209 (parent compound), BDE208, BDE207, BDE206, BDE197, BDE196, BDE183, BDE154, BDE153, BDE138, BDE100, BDE99, BDE85, BDE77, BDE71, BDE49, BDE47, BDE37, and BDE28. Decay of BDE209 in aqueous humic acid solutions is slower; however, after 120 hours of irradiation, product/intermediates appear on GC-ECD chromatograms with equivalent retention times and hexabromodiphenylethers. At shorter irradiation times, reaction intermediates occur with equivalent retention times as nona-, octa-, and hepta-congeners.
Future Activities:
In the next year, solar photolysis experiments with BDE209 solubilized by aqueous humic acids will be continued. Experiments will be conducted with different sources of commercially available humic and fulvic acids, as well as natural organic fractions isolated as dissolved and colloidal fractions from local watersheds. Emphasis in ongoing and future experiments include: (1) analyses of product/intermediate distributions at longer exposure time periods (> 120 hours); (2) confirmation of the identity of reactions product congeners; and (3) tracking of chemical reactions among the humic, fulvic, and natural organic matter using selective 13C-labeled congeners (BDE209). In the next several months, experiments will commence using other congeners as starting materials. Specifically, the rates and product distributions of 2,2',4,4'-tetrabromodiphenylether (BDE47) will be examined.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 16 publications | 4 publications in selected types | All 4 journal articles |
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Hua I, Jafvert C. Flame retardant degrades in sun. Chemical and Engineering News 2003;81(40):31. |
R830398 (2003) |
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Supplemental Keywords:
environmental fate, aquatic, brominated flame retardants, decabromodiphenylether, photochemistry, solar light, polybrominated diphenylether, PBDE, decabromodiphenylether, BDE209, gas chromatography mass spectrometry, GC-MS, 2,2?,4,4?-tetrabromodiphenylether, BDE47., RFA, Scientific Discipline, ENVIRONMENTAL MANAGEMENT, Water, Waste, Ecosystem Protection/Environmental Exposure & Risk, POLLUTANTS/TOXICS, Contaminated Sediments, Environmental Chemistry, Restoration, Resources Management, Environmental Monitoring, Ecology and Ecosystems, Water Pollutants, Aquatic Ecosystem Restoration, Futures, Exp. Research/future, reducitve debromination, biodiversity, reductive debromination, photochemical transformation, contaminated sediment, flame retardants, PBDE, conservation, contaminant uptake, ecological pollutants, exploratory research, remediation, environmental rehabilitation, environmental stress, ecotoxicology, anaerobic biotransformationRelevant Websites:
http://bridge.ecn.purdue.edu/~jafvert/ Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.