Development of a SPE/GC-MS method for the determination of organophosphorus pesticides in food samples using syringe filters packed by GNP/MIL-101(Cr) nanocomposite.

In this study, we report the synthesis and application of a nanocomposite comprising metal-organic framework MIL-101(Cr) and graphene nanopowder (GNP) as a promising sorbent for the extraction of organophosphorus pesticides (OPPs) in juices, water, vegetables and honey samples. A syringe filter, for the first time, was used to host the synthesized nanocomposite and extract the OPPs followed by GC-MS analysis. Different characterization methods including XRD, FTIR, TGA, BET and SEM were employed to confirm the formation of studied nanocomposite. The results indicated that the GNP/MIL-101(Cr) could provide higher capacity for adsorption of OPPs and lower detection limit compared to pristine MIL-101(Cr). The detection limits were 0.005 to 15.0 µg/Kg and the linear range found between 0.05 and 400 µg/Kg. The proposed method showed very good repeatability with the RSD values ranging from 2.9% to 7.1%. The recoveries were between 84% -110% with the spiked levels of 2.0-100.0 µg/Kg.