An amino-functionalized magnetic covalent organic framework composite TpBD-(NH 2 ) 2 @Fe 3 O 4 (Tp=Tp1,3,5-triformylphloroglucinol, BD-(NH 2 ) 2 is 3,3',4,4'-biphenyltetramine) was prepared by post-synthesis modification. Due to its abundant benzene rings and amino groups, large specific surface area and porous structure, the prepared TpBD-(NH 2 ) 2 @Fe 3 O 4 exhibits high extraction efficiency toward sulfonylurea herbicides. Based on this, a new method of magnetic solid-phase extraction with TpBD-(NH 2 ) 2 @Fe 3 O 4 as the sorbent combined with high-performance liquid chromatography and ultraviolet detection was developed for trace analysis of sulfonylurea herbicides in environmental water, soil and tobacco leaves samples from tobacco land. Under the optimized conditions, the limits of detection within 0.05-0.14 μg/L were achieved with a high enrichment factor of 217-260-fold, and the relative standard deviations were 4.9-7.5% (n = 7, c = 0.5 μg/L). The linear range was around three orders of magnitude with the square of correlation coefficient higher than 0.9936. The method was applied to analyze five sulfonylurea herbicides in the environmental water, soil, and tobacco leave samples collected from tobacco land. No sulfonylurea herbicides were detected in these samples. The recoveries of target sulfonylurea herbicides in spiked environmental water, soil, and tobacco leaf samples were found in the range of 90.7-104, 70.7-99.0, and 59.3-97.8%, respectively. The results illustrate that the established TpBD-(NH 2 ) 2 @Fe 3 O 4 -magnetic solid-phase extractionhigh-performance liquid chromatography-ultraviolet detection method is efficient for the analysis of trace sulfonylurea herbicides in environmental samples.

By monomer‐mediated in‐situ growth synthesis strategy, with hydroquinone and 1,3,5‐tris(4‐aminophenyl)benzene as monomers, a core‐shell magnetic porous organic polymer was synthesized through a simple azo reaction. Based on this, a magnetic solid‐phase extraction–high‐performance liquid chromatography–fluorescence detection method was proposed for the analysis of fluoroquinolones in a honey sample. With ofloxacin, ciprofloxacin, enrofloxacin, lomefloxacin, and difloxacin as target analytes, factors affecting the extraction efficiency had been optimized. The LODs were 1.5–5.4 ng/L (corresponding to 0.23–0.81 μg/kg in honey). The linear range was 0.005–20 μg/L for difloxacin, 0.01–20 μg/L for ofloxacin, ciprofloxacin and lomefloxacin, and 0.02–20 μg/L for enrofloxacin. The enrichment factor was 84.4–91.7‐fold with a high extraction efficiency of 84.4–91.7%. The method was assessed by the analysis of target fluoroquinolones in honey samples, and the recoveries for the spiked samples were 79.3–95.8%. The results indicated that the established magnetic solid‐phase extraction–high‐performance liquid chromatography–fluorescence detection method is efficient for the analysis of trace fluoroquinolones in honey.

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