Application of Fe 3 O 4 /RGO Nanocomposite as a Sorbent of Pesticides

In the present study, to extract the residue of seven pesticides (diazinon, chlorpyrifos, ethion, permethrine, cypermethrin, fenvalerate RR and fenvalerate SS) from raisin samples, reduced graphene oxide—Fe3O4 magnetic nanocomposite is applied as an adsorbent and then the preconcentrated pesticides were determined by GC–MS. The application of high adsorption capacity magnetic graphene oxide sheets in pesticides solid phase extraction, provides a fast and easy procedure without filtration or centrifugation. The extraction conditions were optimized by analyzing spiked raisin samples (80 ng mL−1). The parameters affecting the performance of the extraction such as nanoparticles concentration, extraction time, solution pH and desorption conditions were investigated using a univariate optimization process. The maximum adsorption was observed within 15 min at pH 7–8 using 0.4 mg mL−1 of adsorbent with the sample ionic strength of 0.02 M NaCl. Limits of detection and quantification were about 14 and 40 µg kg−1, respectively, for all of pesticides. The validated method was successfully applied for the determination of pesticides in raisin samples.