Magnetic cork composites as biosorbents in dispersive solid-phase extraction of pesticides in water samples

This study assessed the use of magnetic biosorbents in dispersive solid-phase extraction with a gas chromatograph-electron capture detector for the determination of trifluralin, chlorothalonil, transfluthrin, bromopropylate, and bifenthrin in water samples. To our knowledge, this is the first time that magnetic cork composites are used as an adsorbent in dispersive solid-phase extraction. The advantages of magnetic cork composites include their density regulation and high surface areas. The magnetic composites can be recovered using a magnetic field for desorption purposes, which can improve the operation process and reduce the extraction time. Moreover, the parameters affecting the extraction performances were optimized. The method has a limit of detection between 0.30 and 2.02 μg L^-1. Good linearities (R² > 0.99) were obtained in the linear range of 1.00 to 2000 μg L^-1. The relative recoveries of the analytes in tap water, river, and lake water samples spiked at different concentrations ranged between 90% and 104%, and the relative standard deviations were less than 7.1%. Therefore, this study showed that Fe₃O₄/cork magnetic composites can be used as efficient and eco-friendly biosorbents in dispersive solid-phase extraction for the determination of pesticides in water samples. The use of these composites contributes to the current trend of green chemistry.