Ultrasound-assisted surfactant-enhanced emulsification microextraction using a magnetic ionic liquid coupled with micro-solid phase extraction for the determination of cadmium and lead in edible vegetable oils

A novel ultrasound-assisted surfactant-enhanced emulsification microextraction (UASEME) using a magnetic ionic liquid (MIL) coupled with micro-solid phase extraction was developed for the preconcentration of cadmium and lead in edible vegetable oils prior to analysis by graphite furnace atomic absorption spectrometry. MIL [C4mim] [FeCl4] was used as the extractant, non-ionic surfactant Triton X-100 as the emulsifier and Fe3O4 nanoparticles as the sorbent, while ultrasound was applied to assist the dispersion of the extractant and accelerate the mass transfer process. By mixing Fe3O4 nanoparticles with the MIL after UASEME, the phase separation time was shortened and the separation can be simplified by applying an external magnetic field. Under the optimized conditions, the proposed method was validated and the results demonstrated that the method can produce satisfactory linearity, sensitivity, reproducibility and recovery for the analytes. Finally, the method was successfully applied for the determination of Cd and Pb in edible vegetable oil samples.