Anal. Chem. 2005, 77, 1979-1987
Quantitative Analysis of 39 Polybrominated Diphenyl Ethers by Isotope Dilution GC/ Low-Resolution MS Luke K. Ackerman,† Glenn R. Wilson,‡ and Staci L. Simonich*,†,‡
Department of Chemistry and Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331
A GC/low-resolution MS method for the quantitative isotope dilution analysis of 39 mono- to heptabrominated diphenyl ethers was developed. The effects of two different ionization sources, electron impact (EI) and electron capture negative ionization (ECNI), and the effects of their parameters on production of high-mass fragment ions [M - xH - yBr]- specific to PBDEs were investigated. Electron energy, emission current, source temperature, ECNI system pressure, and choice of ECNI reagent gases were optimized. Previously unidentified enhancement of PBDE high-mass fragment ion [M - xH - yBr]- abundance was achieved. Electron energy had the largest impact on PBDE high-mass fragment ion abundance for both the ECNI and EI sources. By monitoring high-mass fragment ions of PBDEs under optimized ECNI source conditions, quantitative isotope dilution analysis of 39 PBDEs was conducted using nine 13C12 labeled PBDEs on a low-resolution MS with low picogram to femtogram instrument detection limits. Polybrominated diphenyl ethers (PBDEs) are a class of flame retardant chemicals used as additives in polymeric materials ranging from polyurethane foam cushioning to printed circuit boards and casings for electronics to textile backings.1 Use of PBDEs has risen sharply over the last 20 years, and in 1999, PBDE global production was more than double the peak annual global production of PCBs at 67 000 metric tons of PBDEs.2,3 PBDEs have been measured at parts-per-million to parts-per-trillion concentrations in biotic and abiotic samples from around the globe.1,4 Since first being measured in environmental samples in 1979,5 concentrations of PBDEs in environmental samples have been steadily increasing. Temporal concentration trends from multiple matrixes, including mothers’ milk, indicate rapid in* Corresponding author. E-mail:
[email protected]. † Department of Chemistry. ‡ Department of Environmental and Molecular Toxicology. (1) de Wit, C. A. Chemosphere 2002, 46, 583-624. (2) Marsteller, B. Bromine Science Environmental Forum. http://www.bsef.com, 2003; Vol. 2003. (3) Breivik, K.; Sweetman, A.; Pacyna, J.; Jones, K. C. Sci. Total Environ. 2002, 290, 181-198. (4) Ikonomou, M. G.; Rayne, S.; Addison, R. F. Environ. Sci. Technol. 2002, 36, 1886-1892. (5) DeCarlo, V. J. Ann. N.Y. Acad. Sci. 1979, 320, 678-681. 10.1021/ac0484676 CCC: $30.25 Published on Web 02/18/2005
© 2005 American Chemical Society
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