Determination of organochlorine pesticide residues in food by polystyrene coated silica magnetic microspheres combined with gas chromatography-mass spectrometry

Abstract

In this work, a sample pre-treatment technology, based on magnetite-silica-polystyrene (Fe3O4@SiO2@PS) composite as the adsorbent, combined with Gas Chromatography-Mass Spectrometry (GC–MS) has been developed and used for the trace analysis of organochlorine pesticide residues in food. SEM, TEM, FI-IR, VSM, XPS, BET, TGA and XRD techniques were used to characterize the synthetic adsorbent material, the adsorbent had excellent magnetic separation properties (saturation magnetization values with 32.7 emu g−1) and adsorption properties (adsorption capacity with 16.67 mg g−1 to 20.53 mg g−1), and the adsorption performance of Fe3O4@SiO2@PS aligned with the pseudo-second-order kinetics. Under the optimal conditions, the developed method showed satisfactory performance within a range of 0.01 to 4 mg L−1 (R2 ≥ 0.9971), the low detection limits (LOD) were from 0.05 to 0.20 μg kg−1, and the quantification limits (LOQ) were from 0.16 to 0.67 μg kg−1, respectively. The spiked recovery rates ranged from 74.7 % and 93.7 %, with relative standard deviations (RSD) from 2.09 % to 6.43 %. Thus, the developed adsorbent and method offer an efficient alternative to the commonly used SPE-based approach.