Microwave assisted magnetic solid phase extraction using a novel amino-functionalized magnetic framework composite of type Fe3O4-NH2@MIL-101(Cr) for the determination of organochlorine pesticides in soil samples

Abstract

In this research, microwave assisted magnetic solid phase extraction (MAE-MSPE) coupled with GC-ECD have been successfully used for the determination of eight organochlorine pesticides in soil samples. Specially, the novel Fe3O4-NH2@MIL-101(Cr) composites as the MSPE sorbent played a role of selective enrichment and purification towards the targets. The MAE-MSPE procedure was optimized focusing on microwave extraction temperature and time, solution pH, the amount of sorbent, ultrasonic extraction time, ionic strength, elution solvent type, elution solvent volume, and elution time. The parameters of the analytical method were evaluated. Under the optimal condition, the detection limits of α-HCH, β-HCH, γ-HCH, δ-HCH, p,p′-DDE, p,p′-DDD, o,p′-DDT, and p,p′-DDT were in the range of 0.15–0.28 ng g−1. Satisfactory recoveries were obtained in the range of 71.2–102.4% with the RSDs less than 10.0%. The obtained results demonstrated that the method was suitable for the trace analysis of OCPs. Additionally, molecular docking was employed to calculate the molecular interactions and free binding energies between MIL-101(Cr) and the organochlorines.