Ionic liquid-linked dual magnetic microextraction: a novel and facile procedure for the determination of pyrethroids...

A novel and facile microextraction technique, termed as ionic liquid-linked dual magnetic microextraction (IL-DMME), was developed for the determination of pyrethroids in honey samples. The distinct advantage of the proposed method is that high recoveries can be readily achieved through the combination of dispersive liquid-liquid microextraction (DLLME) and dispersive microsolid-phase extraction (D-μ-SPE) with the aid of synthetic ionic liquid and non-modified magnetic nanoparticles (MNPs), respectively. In the first DLLME step, [C6MIM]NTf2 was used to extract the pyrethroids without the addition of any toxic dispersive solvent. In the following D-μ-SPE steps, non-modified MNPs were added to retrieve the ionic liquid. The effect of different variables on the extraction efficiency was studied simultaneously using the response surface methodology. The Plackett-Burman design was first employed to screen for the variables that significantly affected the extraction efficiency. Central composite design (CCD) was then introduced to optimize the significant factors using a polynomial fit. The optimal experimental conditions obtained from this statistical evaluation included: ionic liquid volume, 75 μL; S-BaFe quantity, 60 mg; sonication time, 4 min; vortex time, 100 s; desorption time, 150 s; and no addition of salt. Under the optimal conditions, good linearity in the range of 0.5 μg L(-1)-500 μg L(-1), repeatability (RSD 1.1-3.8%), low LODs (0.03-0.05 μg L(-1)) and good recovery (86.7-98.2%) were obtained. Finally, the developed method was evaluated for the extraction and determination of four pyrethroids in real honey samples.