A core-shell structured magnetic covalent organic framework as a magnetic solid-phase extraction adsorbent for phenylurea herbicides

In this work, a core-shell structured magnetic covalent organic framework named as M-TpDAB was constructed with 3,-diaminobenzidine (DAB) and 1,3,5-triformylphloroglucinol (Tp) as building units. MTpDAB was characterized by infrared spectroscopy, nitrogen adsorption-desorption isotherms, powder Xray diffraction, scanning electron microscopy and transmission electron microscopy. Using the M-TpDAB as adsorbent, a simple and highly effective method was proposed for preconcentrating phenylurea herbicides before high performance liquid-phase chromatography analysis. In the optimized conditions, a good linearity was achieved within the range of 0.15-100 ng mL & minus;1 for water sample, 1.0-100.0 ng mL & minus;1 for tea drink samples. The limits of detection for the analytes were 0.05-0.15 ng mL & minus;1 for water sample and 0.30-0.50 ng mL & minus;1 for drink samples. Satisfactory recoveries of spiked target compounds were in the range of 84.6%-105% for water sample and 80.3%-102% for tea drink samples. Finally, the M-TpDAB based method was successfully used to determine phenylurea herbicides in tea drinks and water samples, demonstrating a good alternative for analyzing trace level of phenylurea herbicides in water samples. (c) 2021 Elsevier B.V. All rights reserved. Superscript/Subscript Available

Automated summary

In this study, a core-shell structured magnetic covalent organic framework named M-TpDAB was synthesized and used for preconcentrating phenylurea herbicides before HPLC analysis. The method showed good linearity and detection limits for water and tea drink samples, with satisfactory recoveries. This approach provides a promising alternative for analyzing trace levels of phenylurea herbicides in water samples.