Magnetic solid-phase extraction of benzoylurea insecticides by Fe3 O4 nanoparticles decorated with a hyper-cross-linked porous organic polymer.

A magnetic polytriphenylamine porous organic polymer was prepared through simple self-polycondensation of triphenylamine followed by coprecipitation with Fe2+ and Fe3+ . It was applied as a magnetic adsorbent for the extraction of six benzoylurea insecticides from tomato, cucumber, and watermelon samples before their high-performance liquid chromatography and mass spectral detection. Under the optimized experimental conditions, the established method gave a low limit of detection ranging from 0.05 to 0.1 ng/g and a good linear response ranging from 0.2 to 40 ng/g with coefficients of determination >0.99. The method recoveries for spiked analytes at the concentrations of 3 and 15 ng/g in real samples were in the range of 87.7-106.7% with the relative standard deviations <6.4%. The results indicated that it had a good adsorption capability toward the target analytes due to the π-stacking and hydrogen bonding interactions. The polymer material showed great potential in the efficient extraction of organic compounds from real samples with complex matrixes.