Effective enrichment and detection of trace polybrominated diphenyl ethers in water samples based on magnetic covalent organic framework nanospheres coupled with chromatography-mass spectrometry

Novel core shell structured magnetic covalent organic frameworks were synthesized at room temperature and first applied in water samples for the enrichment of trace polybrominated diphenyl ethers (PBDEs) through magnetic solid-phase extraction. The prepared materials were characterized through transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer and X-ray photoelectron spectroscopy. During adsorption, the parameters affecting extraction and desorption efficiency were further optimized. Combined gas chromatography and mass spectrometry (GC/MS) revealed that high enrichment factors (275–292), low limits of detection (0.12–0.38 ng·L−1), wide linear ranges (0.5–1000 ng·L−1), and good reproducibility (intra-day 1.40%–4.31% and inter-day 5.14%–9.12%) were obtained under optimal conditions. The method successfully detected PBDEs in different water samples.