PEG-modified magnetic Schiff base network-1 materials for the magnetic solid phase extraction of benzoylurea pesticides from environmental water samples

It is necessary to establish a rapid, simple and environmentally friendly detection method for benzoylurea pesticides (BUs) in environmental water samples because of their toxicity in environmental circulation. Herein, a novel polyethylene glycol (PEG) modified magnetic covalent organic framework material based on the Schiff base reaction was prepared (PEG/Fe3O4@SNW-1). This material was used as a sorbent for enriching five BUs by magnetic solid phase extraction prior to detection via high-performance liquid chromatography. After the optimization of several parameters (such as the salinity, extraction time, amount of sorbent, desorption time, etc.) that influenced the recovery of the magnetic solid phase extraction process, the limits of detection (S/N = 3) were defined as less than 1.0 μg L−1, and the limits of quantitation (S/N = 10) were calculated as being lower than 3.4 μg L−1. A satisfactory linear range of 5–1000 μg L−1 was achieved. Finally, the proposed method was applied to analyze benzoylurea pesticides in three environmental water samples. These results indicated that the proposed method was feasible and demonstrated the potential application of the PEG/Fe3O4@SNW-1 material for detecting similar pesticide residues in environmental water samples.