Abstract
Polybrominated diphenyl ethers (PBDEs), produced as flame retardants worldwide, have been phased-out in many countries, and chlorinated and non-chlorinated organophosphates and non-PBDE brominated formulations (e.g., Firemaster 550 (FM550)) have entered the consumers’ market. Recent studies show that components of organophosphate esters and FM550 are frequently detected in many products common to human environments. Therefore, urinary metabolites of these compounds can be used as human exposure biomarkers. We developed a method to quantify nine compounds in 0.4 mL urine: diphenyl phosphate (DPhP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP), bis-(1-chloro-2-propyl) phosphate, bis-2-chloroethyl phosphate, di-p-cresylphosphate, di-o-cresylphosphate (DoCP), di-n-butyl phosphate, dibenzyl phosphate (DBzP), and 2,3,4,5-tetrabromobenzoic acid. The method relies on an enzymatic hydrolysis of urinary conjugates of the target analytes, automated off-line solid phase extraction, reversed phase high performance liquid chromatography separation, and isotope dilution-electrospray ionization tandem mass spectrometry detection. The method is high-throughput (96 samples/day) with detection limits ranging from 0.05 to 0.16 ng mL−1. Spiked recoveries were 90–113 %, and interday imprecision was 2–8 %. We assessed the suitability of the method by analyzing urine samples collected from a convenience sample of adults (n = 76) and from a group of firefighters (n = 146). DPhP (median, 0.89; range, 0.26–5.6 ng mL−1) and BDCPP (median, 0.69; range, 0.31–6.8 ng mL−1) were detected in all of the non-occupationally exposed adult samples and all of the firefighter samples (DPhP [median, 2.9; range, 0.24–28 ng mL−1], BDCPP [median, 3.4; range, 0.30–44 ng mL−1]); DBzP and DoCP were not detected in any samples.
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Acknowledgments
We gratefully acknowledge Dr. Kenneth Fent (NIOSH, CDC) for providing firefighters’ de-identified urine specimens for method validation, and Dr. Sam Caudill for helping with statistical analysis. This work was supported in part by an appointment (LW) to the Research Participation Program at the CDC, administered by the Oak Ridge Institute for Science and Education through an inter-agency agreement between the U.S. Department of Energy and CDC.
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The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention (CDC). Use of trade names is for identification only and does not imply endorsement by the CDC, the Public Health Service, or the US Department of Health and Human Services
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Jayatilaka, N.K., Restrepo, P., Williams, L. et al. Quantification of three chlorinated dialkyl phosphates, diphenyl phosphate, 2,3,4,5-tetrabromobenzoic acid, and four other organophosphates in human urine by solid phase extraction-high performance liquid chromatography-tandem mass spectrometry. Anal Bioanal Chem 409, 1323–1332 (2017). https://doi.org/10.1007/s00216-016-0061-4
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DOI: https://doi.org/10.1007/s00216-016-0061-4