Determination of newly synthesized dihydroxylated polybrominated diphenyl ethers in sea fish by gas chromatography-tandem mass spectrometry

Dihydroxylated polybrominated diphenyl ethers (diOH-PBDEs) can be natural products of marine organisms or the metabolites of PBDEs. The optimal determination method and concentration of diOH-PBDEs in seafood are unknown due to a lack of commercially available standards. In the present study, diOH-PBDEs were synthesized, and an efficient measurement method for OH-PBDEs and diOH-PBDEs in sea fish muscle samples, including extraction, clean-up and gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis, was established. Pressurized liquid extraction (PLE) followed by partitioning with a KOH solution and florisil cartridge clean-up proved to be a reliable and robust method for detecting all OH-PBDEs/diOH-PBDEs. GC-MS/MS with an electron ionization (EI) source analysis was a sensitive analytical instrument for OH-PBDEs/diOH-PBDEs. The recovery using this method ranged from 19% to 101%, 28%–88% and 42%–90% for 10 ng, 20 ng and 40 ng spiking levels, respectively. The equipment detection limits (EDLs) were in the range of 0.31–2.78 pg/μL, and the limits of detection (LOD) for the method were in the range of 5.07–38.74 pg/g wet weight. Concentrations of diOH-PBDEs in the marine fish muscle samples were in the range of 32.43–1528.63 pg/g wet weight. Similar compositions of OH-PBDEs/diOH-PBDEs were found within the same family of marine fish.