title: Development of an analytical method to quantify PBDEs, OH-BDEs, HBCDs, 2,4,6-TBP, EH-TBB, and BEH-TEBP in human serum.
abstract: Polybrominated diphenyl ethers (PBDEs) flame retardants (FRs) were phased-out in the mid-2000s (penta- and octaBDE) and 2013 (decaBDE); however, their hydroxylated metabolites (OH-BDEs) are still commonly detected in human serum. Today, novel FRs such as Firemaster® 550, a mixture that contains two brominated compounds, EH-TBB and BEH-TEBP are used as replacements for PBDEs in some applications, and there is a need to develop a comprehensive analytical method to assess exposure to both legacy PBDEs and novel FRs. This study developed a solid-phase extraction (SPE)-based method to analyze PBDEs, OH-BDEs, 2,4,6-tribromophenol (TBP), hexabromocylcododecane isomers (HBCDs), EH-TBB, and BEH-TEBP in human serum. Briefly, serum proteins were first denatured with formic acid, and then the target analytes were isolated using a SPE column. Finally, the extract was cleaned and fractioned using a silica SPE column. Method performance was assessed by spiking fetal bovine serum with 1-2 ng of the target analytes, and method accuracy was quantified by comparison to a serum Standard Reference Material (SRM). The developed method showed good recovery and accuracy for all target analytes with the exception of the very low and very high molecular weight PBDE congeners. Using this method, 43 serum samples collected from the Healthy Pregnancy, Healthy Baby Study (HPHB) cohort in Durham, NC, USA were analyzed for FRs. A novel finding was the ubiquitous detection of 2,4,6-TBP, at levels greater than the individual PBDE congeners. Furthermore, 2,4,6-TBP was positively correlated with PBDEs, suggesting that they may have a similar source of exposure, or that 2,4,6-TBP may result from metabolism of PBDEs in vivo.
authors: Nicholas School of the Environment, Levine Science Research Center, Duke University, Room A220, Box 90328, Durham, NC, 27708, USA.
authors: Craig M
authors: CM
authors: Butt
authors: Department of Statistics, Rice University, 6100 Main St. MS-138, Duncan Hall, Box 1892, Houston, TX, 77005-1827, USA.|Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
authors: Marie Lynn
authors: ML
authors: Miranda
authors: Nicholas School of the Environment, Levine Science Research Center, Duke University, Room A220, Box 90328, Durham, NC, 27708, USA. heather.stapleton@duke.edu.
authors: Heather M
authors: HM
authors: Stapleton
mesh_terms: D001769:Blood; D005411:Flame Retardants / Q000032:analysis*; D006801:Humans; D012015:Reference Standards; D052616:Solid Phase Extraction
chemical_list: D005411:Flame Retardants
keywords: Flame retardants; Mass spectrometry; Method development; Serum analysis