Study on Adsorption of Two Functionalized Conjugated Microporous Polymers: Extraction of Carbendazim and Thiabendazole in <i>Ophiopogon japonicus</i>

In this study, two novel conjugated microporous polymers modified with functional groups were synthesized. Meanwhile, static and dynamic adsorption tests were conducted on the obtained materials. To achieve the best extraction efficiency, the parameters of the pipette-tip solid-phase extraction procedure were optimized, including the amount of adsorbent, the type and amount of washing solvent, and the elution solvent. The results demonstrate that the adsorption performance of the sulfonated conjugated microporous polymer is remarkably superior to that of the aminated conjugated microporous polymer. Under the optimal conditions, the linear range for targets was 0.05-10.00 µg/g using this method, the limits of detection were 0.009 µg/g for carbendazim and 0.004 µg/g for thiabendazole, and the recoveries were in the range of 80.7%-108.3% for carbendazim and 87.4%-119.2% for thiabendazole, which was successfully applied to the analysis of target residues in actual samples. In addition, the adsorption capacity of material prepared in this study was superior to that of several commercially available adsorbents. Therefore, a method for the determination of target residues in Ophiopogon japonicus by pipette-tip solid-phase extraction coupled with high-performance liquid chromatography using the material adsorbent was established. This method is important for detecting target residues.