T5 PM Emerging Pollutants
Tuesday, 15 November 2005: 1:50 PM - 5:30 PM in 321-323

(AAA-1117-811960) Congener specific determination of PBDEs in four flame-retardant mixtures, DE-71, Bromkal 70-5DE, DE-79 and Bromkal 79-8DE.

La Guardia, M¹, Hale, R¹, Harvey, E¹, ¹ Virginia Institute of Marine Science, Gloucester Point, VA, USA

ABSTRACT- Decabromodiphenyl ether (BDE-209) has been under increased scrutiny due in part to its tendency to debrominate to lower brominated polybrominated diphenyl ethers (PBDEs) under laboratory conditions and possibly once released to the environment. Some of the less brominated congeners (e.g. BDE-47 and -99) are bioaccumulative endocrine disruptors. These have also become environmentally ubiquitous, akin to other persistent organic pollutants (POPs), such as PCBs. The full range of constituents of the technical mixtures must be understood in order to identify degradation products of -209, possible mixture contaminants and sources of accumulated PBDEs in biota. Previous studies have identified the major congeners within these formulations, but few have focused on their minor constituents. This has been exacerbated by the lack of commercially available standards and dependable analytical methods. Here we utilize some recent technical enhancements and the emergence of new analytical standards to develop a method capable of analyzing a larger suite of mono- through deca-BDEs. PBDEs were separated and detected by gas chromatograph selected-ion-monitoring mass spectrometry (GC-SIM) in electron-capture negative ionization (ECNI) mode, monitoring ions 79 and 81 m/z. Structural conformation based on the molecular ion and fragmentation patterns of the identified compounds was established by GC-MS using ECNI and electron ionization (EI) modes, scanning 50-1000 m/z. Four commercial PBDE formulations were examined: two Penta-BDE products (DE-71 and Bromkal 70-5DE) and two Octa-BDE products (DE-79 and Bromkal 79-8DE). In these products we identified and quantified 26 individual PBDE congeners, at concentrations > 0.02% by weight. (To our knowledge, this is the first time seven of these congeners have been identified in these commercial mixtures). These congeners are: BDE-75 and -77 detected in DE-71, -138, -140, -144, -184, and -201 in DE-79 and -144, -184 and -201 in Bromkal 79-8DE. There were also 11 additional congeners detected without corresponding analytical standards. These were tentatively assigned identifications based on molecular ion and fragmentation information.

Key words: PBDEs, emerging contaminants, endocrine disruptors, flame-retardants