Background Traditional brominated flame retardants, polybrominated biphenyl ethers, have been prohibited from being used in commercial products because of their health hazards on human and animals. Novel brominated flame retardants (NBFRs) have gradually been used as substitution. Due to their potential health hazards, NBFRs exposure assessment cannot be ignored.
Objective This methodological study aims to establish a method for determination of NBFRs in water by solid phase extraction and gas chromatography-mass spectrometry.
Methods Each NBFR standard sample was separately qualitatively analyzed by gas chromatographyelectron impact ionization-mass spectrometry (GC-EI-MS) and gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS) to optimize parameters of mass spectrometry. In the optimization of solid phase extraction, the mixture of dichloromethane and hexane (V:V, 1:1) was used as elution solvents; the spiked water samples (20L) of NBFRs were extracted using three kinds of packed columns, XAD-2, XAD-8, and C18, to select appropriate adsorbents. In addition, the elution times were optimized for packed columns with appropriate adsorbents. Finally, this proposed analysis protocol was validated and applied to the tap water samples collected from Shanghai and groundwater samples from a rural area in northern China.
Results A higher sensitivity was found in identifying NBFRs by GC-NCI-MS than by GC-EI-MS. XAD-2 showed a good adsorption efficiency, and the recovery rate met the requirements for quality control of large-volume water sample analysis when the samples were eluted for four times. The instrument detection limit (IDL) of GC-NCI-MS was 0.001-1.0 ng/mL for 15 target chemicals; the linearity range was 0.005-200 ng/mL; the range of determination coefficients (R2) was 0.995 4-0.999 9. The recovery ranges of low-, mid-, high-concentration spiked water samples were 62.3%-112.2%, 61.1%-112.1%, and 65.4%-107.0%, respectively; and the relative standard deviations (RSD, n=5) were 1.5%-20.8%, 1.0%-26.1%, and 0.7%-11.5%, respectively. NBFRs were detected in the tap water samples from Shanghai and the groundwater samples from a rural area in northern China.
Conclusion This method basically meets the requirements for analyzing NBFRs in large-volume water samples, and can be applied to water sample analysis.
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