Determination of Five Polybrominated Diphenyl Ethers Residues in Deep-Sea Fish Oil Using Gas Chromatography-Negative Chemical Ionization/Mass Spectrometry

Polybrominated diphenyl ethers (PBDEs) are a kind of brominated flame retardants (BFRs), which refer to compounds used in some plastics to impede or even suppress the combustion process. As in the form of emissions or through disposal as plastics, PBDE residues have been found in both environment and biota. In this study, an analytical method was developed for the simultaneous determination of 5 PBDE residues in deep-sea fish oil. PBDEs were extracted from deep-sea fish oils with n-hexane, cleaned up on a silica gel column, and determined by using gas chromatography-negative chemical ionization/mass spectrometry (GC-NCI/MS) in the selected ion-monitoring (SIM) mode, with PCB103 as the internal standard. Meanwhile, the characteristic ion and fragmentation mechanism of some PBDEs in NCI/MS were evaluated. Recovery studies were performed at 20.0 and 100.0 μg/kg fortification levels for each PBDE, and the recoveries ranged from 88.6% to 111.3% with relative standard deviations between 3.8% and 13.5% for different PBDEs. The limits of detection (LOD) were from 0.77 to 1.34 μg/kg for the different PBDEs. The developed method was linear over the range assayed, 1.0–500.0 μg/kg, with correlation coefficients larger than 0.9992. The developed method has also been successfully applied to the determination of PBDEs in several deep-sea fish oil samples and the three most abundant PBDEs (PBDE-47, PBDE-99 and PBDE-100) were found.