Application of ionic-liquid-supported magnetic dispersive solid-phase microextraction for the determination of acaricides in fruit juice samples

In this study, ionic liquid (IL) supported magnetic dispersive solid-phase microextraction was developed and a systematic investigation was conducted on imidazolium ILs for their extraction performance. This nano-based pretreatment procedure was then applied for the determination of acaricides in fruit juice samples for the first time. A feature of this technique is that the commonly laborious chemical modification of magnetic nanoparticles (MNPs) was skillfully circumvented. Because of the combination of ILs, dispersive liquid-liquid microextraction, and dispersive MNP solid-phase microextraction, the extraction efficiency can be significantly improved using commercial MNPs. Parameters of the extraction method were investigated by one-factor-at-a-time approach. The optimal experimental conditions were as follows: emulsification for 2 min by sonication with the addition of 50 μL [C₆MIM][NTf₂] in the dispersive liquid-liquid microextraction step and vortexing for 90 s after adding 40 mg spherical barium ferrite nanoparticles (20 nm). The desorption time was 2 min. Good linearity (0.5-500 ng/mL) and detection limits within the range of 0.05-0.53 ng/mL were achieved. The application of the proposed method was demonstrated by the analysis of real fruit juice samples, in which recoveries between 85.1 and 99.6% were obtained.