Synthesis and Characterization of 2,3-Dibromopropyl-2,4,6-tribromophenyl Ether (DPTE) and Structurally Related Compounds Evidenced in Seal Blubber and Brain

Abstract

The unknown compound UBC-1 previously described as the major organobromine contamination in the blubber extract of a hooded seal (Cystophora cristata) from the Barents Sea was identified as 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE). DPTE, which is the main component of the brominated flame retardant (BFR) Bromkal 73-5 PE, was synthesized by electrophilic addition of bromine to allyl-2,4,6-tribromophenyl ether (ATE). The chirality of DPTE was proven by gas chromatographic enantioseparation of the synthesized racemate. On the basis of GC/ECNI-MS ion chromatograms (m/z79 and 81), DPTE was the dominating organobromine compound in blubber and brain samples of hooded seals and harp seals (Phoca groenlandica) from the Barents and Greenland Seas. The concentrations of DPTE in blubber and brain were up to 470 and 340 microg/kg wet weight. Next to DPTE, the natural dibromo-trichloromonoterpene (MHC-1), the anthropogenic BDE 47 and BDE 99, as well as ATE, 3,5-dibromo-2-(2',4'-dibromo)-phenoxyanisole (6-MeO-BDE 47), 2-bromoallyl-2,4,6-tribromophenyl ether (BATE), and 4,6-dibromo-2-(2',4'-dibromo)-phenoxyanisole (2'-MeO-BDE 68) were present with decreasing relevance. BATE, which was detected for the first time in environmental samples, was synthesized from DPTE by E2 elimination. In brain samples of the harp seals, DPTE, ATE, and BATE were the most abundant organobromine compounds, whereas polybrominated diphenyl ethers (PBDEs) and MHC-1 were virtually absent. This indicated that DPTE, ATE, and BATE were able to penetrate the blood-brain barrier. The general co-occurrence of ATE and BATE in samples contaminated with DPTE support the hypothesis that these compounds are biotransformation products of DPTE. Anaerobic transformation studies of DPTE with super-reduced corrinoids resulted in the formation of ATE. Furthermore, 2,4,6-tribromophenol (TBP) and two other unknown minor transformation products were detected.

Maternal transfer of emerging brominated and chlorinated flame retardants in European eels

“…TBP-DBPE concentrations higher than 1 ng L -1 were detected in the tank water, suggesting that the increased concentrations in hormone treated eels might have indeed been caused by a continued uptake from TBP-DBPE leaching out of the recirculation system into the tank water during the maturation process. The repeated detection of TBP-DBPE in eels that had not been kept in tanks prior to sampling tissue remained inexplicable, because there is no report on current production or use and the only known producer, Chemische Fabrik Kalk, Germany, ceased its production in the 1980s (von der Recke & Vetter, 2007). Another potential source of TBP-DBPE could be remobilisation from other tissues during the artificial maturation process.…”

“…Another potential source of TBP-DBPE could be remobilisation from other tissues during the artificial maturation process. Corresponding TBP-DBPE transformation products 1,3,5-tribromo-2-(2-propen-1-yloxy)-benzene (TBP-AE) and 2-bromoallyl-2,4,6-tribromophenyl ether (BATE) (von der Recke & Vetter, 2007) had the second and third highest concentration and detection frequency (>90%) of alternate BFRs in all tissue types of hormone treated eels, while detection frequencies in the comparison group were below 50% and TBP-AE could not be detected in gonads ( Table 2). The transformation products were also found in water samples, however in much lower concentrations (< 1pg L -1…”

“…A continuous uptake as well as a potential metabolism of TBP-DBPE during maturation is reason for concern, because TBP-DBPE as well as its transformation products TBP-AE and BATE are known endocrine disrupters and able to penetrate the brainblood-barrier (von der Recke & Vetter, 2007), making them a potential danger to the healthy development of offspring.…”

Emerging Brominated Flame Retardants in the Environment

“…[90,129] and an additive FR for expanded polystyrene and foamed polystyrene (http://www.chemtura.com, accessed March 2010). It may also be used as a synergist for aromatic bromine containing FRs in applications where maximum process temperatures do not exceed 150 C. ATE can also be formed from anaerobic degradation of 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE, CAS 35109-60-5) and is probably also formed metabolically [130]. ATE is listed as an LPV chemical in the EU [8].…”

Desenvolvimento de procedimentos analíticos para a determinação de não-metais via moléculas diatômicas por espectrometria de absorção molecular de alta resolução com fonte contínua

“…Geralmente eles são aditivos misturados às matrizes acima descritas e não são quimicamente ligados a elas, portanto podem ser separados por lixiviação para o meio ambiente [112]. A eles são atribuídos caráter cancerígeno; por isso, vários estudos abordam sua potencial contaminação, bioacumulação e toxicidade em animais [113][114][115]; e as consequências da exposição humana a esses compostos [116][117][118][119].A diretiva europeia de restrição de uso de certas substâncias perigosas (RoHS) em equipamentos elétricos e eletrônicos 2002/95/EC restringe o uso de seis substâncias (chumbo, cádmio, mercúrio, crômio hexavalente, PBB e PBDE) na fabricação de diversos tipos de equipamentos elétricos e eletrônicos, não apenas em todo o produto, mas em ionização por elétron (EI-HRMS) [126][127][128] e dissociação por captura de elétrons (ECD) [122,123]; e algumas baseadas em cromatografia líquida (LC) acopladas a MS sequencial com fotoionização à pressão atmosférica (APPI-MS/MS) [129][130][131] e MS com ionização por eletrospray (ESI-MS) [128,132]. Há testes preliminares que podem ser aplicados para determinar se as aomstras poderiam estar dentro da diretiva RoHS.…”