Construction of magnetic recoverable porous electron-rich organic frameworks for efficiently enrichment of phenylurea herbicides from water and milk samples prior to HPLC detection

Porous electron-rich organic frameworks have attracted an increased attention in the adsorption and removal of pollutants due to their abundant electron-rich nitrogen atoms, which can effectively interact with positively charged substance. In this study, a porous electron-rich organic framework (Car-POF) and positively charged amino-functionalized magnetic nanoparticles (Fe 3 O 4 -NH 2 ) were used to construct a magnetic electron-rich Fe 3 O 4 -NH 2 @Car-POF for the enrichment of some phenylurea herbicides from water and milk samples prior to high performance liquid chromatographic detection. The adsorption capacity of Fe 3 O 4 -NH 2 @Car-POF for the phenylureas ranged from 14.93 to 28.83 mg g −1 . The LODs were observed in the range of 0.05–0.20 ng mL −1 and 0.5–1.5 ng mL −1 , and LOQs in the range of 0.17–0.66 ng mL −1 and 1.7–5.0 ng mL −1 for water and milk samples with RSD less than 9.0. The adsorption studies with cationic and anionic dyes revealed that Fe 3 O 4 -NH 2 @Car-POF is favorable for the adsorption of positively charged compounds.