Application of Hydrophobic Magnetic Nanoparticles as Cleanup Adsorbents for Pesticide Residue Analysis in Fruit, Vegetable, and Various Soil Samples.

Abstract

A cleanup procedure based on hydrophobic magnetic nanoparticles for QuEChERS extraction followed by GC-MS method for the simultaneous determination of 16 organochlorine pesticides was developed. The type and amount of cleanup adsorbents (C18/GCB/Fe3O4/Fe3O4@Triton), the volume and polarity of the extraction solvent were optimized. The method was validated according to SANTE/11813/2017 and ICH/2005/Q2/R1 guidelines. Spiked-sample recoveries of 84-108% with RSD below 8% were obtained for all the tested pesticides in strawberry. Quantification was carried out using matrix-matched calibration plots, which displayed good linearity (R2 > 0.99), the limits of quantification being less than the maximum residue limits (MRL) for food. The elaborated procedure with satisfactory results was applied in to determine the pesticides in fruit, vegetable (strawberries, avocadoes, watermelons, radishes, and flesh kiwis) and soil (agricultural, urban and lab-made) samples. The most frequently founded pesticide residues were 4,4'-DDE, 4,4'-DDD, lindane, and 4,4'-DDT, which in all cases were found to be below MRL. The highest concentration of 4,4'-DDT was founded in agricultural and lab-made soils.