Picogram per liter level determination of hydroxylated polybrominated diphenyl ethers in water by liquid chromatography–electrospray tandem mass spectrometry

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have obtained increasing attention; however, few analytical methods are available for sensitive identification of these compounds in water. In this paper, we developed a highly sensitive method for simultaneous determination of nine OH-PBDEs in water by using hydrophilic–lipophilic balanced cartridge extraction, silica cartridge purification, and the combination of derivatization with liquid chromatography–electrospray tandem mass spectrometry. The effective sample pretreatment process and greatly increased instrumental sensitivity by derivatization allow for the quantification of nine OH-PBDEs at a method detection limit of 0.04–3.5 pg/L with 1-L wastewater treatment plant effluent or river water. This method was applied to wastewater effluent and river water samples collected in Beijing, China, where two OH-tetraPBDEs were detected at concentrations ranging from 0.63 to 1.0 pg/L (5-OH-BDE-47) and from 0.92 to 1.3 pg/L (6-OH-BDE-47).