Synthesis of nitrogen-rich magnetic hypercrosslinked polymer as robust adsorbent for the detection of neonicotinoids in honey, tomatoes, lettuce and Chinese cabbage

Abstract

In this study, a novel nitrogen-rich magnetic hypercrosslinked polymer (Fe3O4@Ph-HCP) was fabricated via a facile one-pot reaction of 1,3,5-triphenylbenzene, 2,4-dichloropyrimidine and phenyl-functionalized magnetic Fe3O4 nanoparticles. The Fe3O4@Ph-HCP possessed high specific surface, abundant nanopores and good stability. Especially, Fe3O4@Ph-HCP exhibited excellent adsorption capability with fast adsorption rate to neonicotinoid insecticides. It was applied as a superior magnetic adsorbent for rapid enrichment and isolation of four neonicotinoid insecticides (thiamethoxam, imidacloprid, acetamiprid and thiacloprid) from honey, tomato, lettuce and Chinese cabbage samples prior to high performance liquid chromatography-diode array detection. Under the optimized conditions, the good linearity was obtained in the range of 1–1000 ng g−1 for honey, tomato, lettuce and Chinese cabbage samples, and the detection limits (S/N = 3) were 0.30–0.67 ng g−1 for honey, 1–1.5 ng g−1 for tomato, lettuce and Chinese cabbage. The spiked recoveries were 80.1–111%, and relative standard deviations were less than 10.0%. These results demonstrate that the developed method can be used as a good alternative method for sensitive determination of neonicotinoid insecticides in complex samples.