Synthesis of flower-like polyamine/C dual-functional magnetic titanium dioxide-based oligopolymer microspheres and their application for the purification, detection and dietary exposure assessment of 52 pesticides in bayberry samples.

Novel core-shell flower-like polyamine/C dual-functional magnetic titanium dioxide-based oligopolymer (FeO@fTiO-PAPMA/C) microspheres were synthesized and used as a magnetic solid-phase extraction (MSPE) adsorbent to purify 52 pesticides in bayberry samples. The FeO@fTiO-PAPMA/C microspheres were fully characterized and it can obviously improve the purification ability of 52 pesticides in bayberry samples. Coupled to LC-MS/MS, the developed method indicated low limits of detection (LODs) and limits of quantification (LOQs) of 0.1-1.0 μg/kg and 0.3-3.0 μg/kg, respectively. Recoveries in bayberry samples ranged from 71.1 % to 108 %, with relative standard deviations (RSDs) of 1.5 % ∼ 9.6 % at four spiking levels. The established MSPE-LC-MS/MS method was employed to analyze 52 pesticide residues in 374 bayberry samples, and the top five pesticides with the highest detection rate were phenylether metronidazole, pyraclostrobin, carbendazim, imidacloprid and tebuconazole. Furthermore, the risk assessment to the 30 pesticides showed that the levels of pesticides found in bayberry samples do not pose a health risk.