Magnetic effervescence-assisted switchable solvent dispersive liquid-liquid microextraction for the determination of pyrethroids in edible fungi

A simple, rapid, effective, and environmental friendly analytical procedure for determining three pyrethroids (tetramethrin, lambda-cyhalothrin and fenvalerate) in edible fungi was developed by high-performance liquid chromatography-diode array detection after magnetic effervescence-assisted switchable solvent dispersive liquid-liquid microextraction (MEA-SHS-DLLME). In the extraction procedure, hexanoic acid and carbon dioxide were used as the extraction and dispersion solvents. The magnetic Fe3O4@ graphene with large specific surface area were used to adsorb the extraction solvent and the target analytes. The optimized conditions were as follows: sodium hexanoate 45 mg, citric acid 90 mg, sodium bicarbonate 60 mg, Fe3O4@ graphene mixing ratio 1:6, and dosage of Fe3O4@ graphene 25 mg. Under these conditions, accuracy and precision were demonstrated at the concentration range of 1.25–125 mg/kg, and the correlation coefficients were between 0.9903 and 0.9998. The limits of detection and quantification were 0.0067–0.0329 mg/kg and 0.0224–0.1096 mg/kg, and the extraction recovery was 81.0–97.4 % with relative standard deviations