Magnetic mixed hemimicelles dispersive solid-phase extraction based on ionic liquid-coated attapulgite/polyaniline-polypyrrole/Fe 3 O 4 nanocomposites for determination of acaricides in fruit juice prior to high-performance liquid chromatography-diode array detection.

In this research, a novel method using magnetic mixed hemimicelles dispersive solid-phase extraction (MMHDSPE) based on C16 mimBr-coated attapulgite/polyaniline-polypyrrole/Fe3 O4 (ATP/PANI-PPY/Fe3 O4 ) nanocomposites were investigated for enrichment and separation of three acaricides in fruit juice. In this method, we combined the simplicity and speed of dispersive solid-phase extraction, the advantages of mixed hemimicelles and the facility of the phase separation of the magnetic nanoparticles to develop a simple, rapid, sensitive, and effective method for detecting target analytes from the juice samples. ATP/PANI-PPY/Fe3 O4 nanocomposites were successfully synthesized using a one-pot method. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The experimental factors affecting the extraction efficiency including the sorbent type, amount of ATP/PANI-PPY/Fe3 O4 nanocomposites, volume of ILs, sonication time, pH, and desorption conditions were optimized. Under the optimal conditions, good linearity was observed for all target analytes, with correlation coefficients (r2 ) ranging from 0.9994 to 0.9999; the limits of detection (LOD) were in the range of 0.16-0.57μgL-1 , and the recoveries of analytes using the proposed method ranged between 88.67% and 95.10%. The sorbents exhibited excellent repeatability in the range of 1.83-4.24% in extracting the three target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.19-6.24% and 2.23-8.36%, respectively. The method was successfully applied to analyze fruit juice samples by rapid preconcentration of acaricides.