Determination of selected pesticides by GC-FID after CNO/MOF nanocomposites-based dispersive solid phase extraction coupled with liquid microextraction

A nanocomposite based on carbon nano onion and ZIF67 metal-organic framework has been synthesized and was characterized by X-ray diffraction spectroscopy, scanning electron microscopy, and Furrier-transformed infrared spectroscopy. The extraction performance of organochlorine and organophosphorus pesticides by the synthesized nanocomposite was evaluated. The prepared sorbent was used as a sorbent in the dispersive solid-phase extraction method, and then dispersive liquid-liquid microextraction was executed for more cleanup and preconcentration. The final extracted analytes were analyzed by gas chromatography. In this combined method, the analytes were extracted with only 10 mg of sorbent and 20 μL of tetrachloride carbon as extraction solvent. The affecting parameters on the extraction efficiency were thoroughly investigated by one parameter at a time approach. The precision of the method was measured through intra-day and inter-day (n = 5) repetitive experiments that showed RSD values lower than 6.9 %. The combination of the optimized dispersive solid-phase extraction with dispersive liquid-liquid microextraction followed by gas chromatography provided a powerful procedure for pesticide analysis in real samples.