title: Analysis of polybrominated diphenyl ethers and emerging halogenated and organophosphate flame retardants in human hair and nails.
abstract: A method for the digestion, extraction, fractionation, and analysis of three classes of flame retardants, including 36 polybrominated diphenyl ethers (PBDEs), 9 halogenated alternative flame retardants (AFRs), and 12 organophosphate esters (OPEs) in human hair and nail samples was developed. The method employed HNO3/H2O2 digestion, liquid-liquid extraction with (4:1 vol) hexane:dichloromethane, fractionation on a 6g column of 2.5% water deactivated Florisil, and analysis by gas chromatographic mass spectrometry. The accuracy and precision of the method was validated using spiked samples of 6 replicates for both hair and nail samples. The method validation results showed good accuracy and precision for all PBDEs except BDE-209, all AFRs except hexabromobenzene (HBB), and all of the 12 OPEs, with average recovery efficiencies>90% and relative standard deviations (RSDs)<10%. The average recovery efficiencies for HBB were between 60% and 86%, with RSDs<10%. BDE-209 had recovery efficiencies of 64% (RSD, 13%) for hair and 71% (RSD, 10%) for nail. This method was applied to analyze 5 human hair and 5 fingernail samples from the general student population at Indiana University Bloomington campus. BDE-47 and BDE-99 were the predominant PBDEs detected in both hair and nail samples, with a concentration range of 11-620 and 4.6-780ng/g (dry weight) in hair and 7.3-43 and 2.1-11ng/g in nails, respectively. Di-(2-ethylhexyl)-tetrabromophthalate (TBPH) and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) were detected in all the samples, with concentrations of 20-240 and 11-350ng/g in hair and <17-80 and <9.2-71ng/g in nails, respectively. Among the 12 OPEs analyzed, tris(2-chloroethyl)phosphate (TCEP), tris(1-chloro-2-propyl)phosphate (TCIPP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), and triphenyl phosphate (TPHP) were most often detected. The concentrations of these OPEs (summed together) were 1100-3900 and 380-18,000ng/g in hair and nails, respectively. These levels exceed those of both the PBDEs and the AFRs.
authors.affiliation: School of Public and Environmental Affairs, Indiana University, Bloomington, IN 47405, United States.
authors.forename: Liang-Ying
authors.initials: LY
authors.lastname: Liu
authors.affiliation: School of Public and Environmental Affairs, Indiana University, Bloomington, IN 47405, United States.
authors.forename: Amina
authors.initials: A
authors.lastname: Salamova
authors.affiliation: School of Public Health, Indiana University, Bloomington, IN 47405, United States.
authors.forename: Ka
authors.initials: K
authors.lastname: He
authors.affiliation: School of Public and Environmental Affairs, Indiana University, Bloomington, IN 47405, United States. Electronic address: HitesR@Indiana.edu.
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Hites
mesh_terms: D002623:Chemistry Techniques, Analytical; D005411:Flame Retardants / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006197:Hair / Q000737:chemistry*; D055768:Halogenated Diphenyl Ethers / Q000032:analysis*; D054879:Halogenation; D006801:Humans; D059625:Liquid-Liquid Extraction; D009262:Nails / Q000737:chemistry*; D010755:Organophosphates / Q000032:analysis; D012680:Sensitivity and Specificity
chemical_list: D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers; D010755:Organophosphates
keywords: Alternative flame retardants; Biomonitoring; Gas chromatographic mass spectrometry; Human hair and nail; Organophosphate ester flame retardants; Polybrominated diphenyl ethers