Utilization of magnetic solid phase materials comprised of deep eutectic solvents and spent mushroom biochar for the extraction of pyrethroids in water.

Pyrethroids are crucial for crop protection, but their abuse has led to significant concerns for threatening human health. Here, two new types of dispersed magnetic solid-phase adsorbents with high adsorption performance for pyrethroids were designed and synthesized. Spent mushroom substrate (SMS) was first pyrolyzed into biochar and magnetic particles were then introduced. Non-ionic and ionic deep eutectic solvents (DESs) were selected as functional monomers to modify magnetic spent mushroom substrate biochar (MSBC). The adsorbents prepared were characterized. Turns out: under the optimum conditions, MSBC loaded with non-ionic DES synthesized with Menthol: Capric acid = 2:1 (DES1@MSBC) and MSBC loaded with ionic DES synthesized with Tetrabutylammonium bromide: Capric acid = 1:2 (DES2@MSBC) exhibited high adsorption performance; DES1@MSBC and DES2@MSBC achieved a recovery range of 88.97 %-97.81 % and 85.72 %-91.80 % for six pyrethroids, respectively; characterization results confirmed the successful loading of magnetic particles and DESs onto the surface of biochar. Finally, a method for detecting pyrethroids in water samples was established, demonstrating high linearity within the range of 0.5-2.5 μg/mL, with a limit of detection (LOD) of 0.15 μg/mL and a limit of quantification (LOQ) of 0.5 μg/mL (R > 0.99). These two magnetic solid-phase adsorbents have the advantages of high efficiency, environmental friendliness, and time-saving operation, while also providing a new strategy for the removal of pyrethroids in water.