Microwave-assisted preparation of poly(ionic liquids)-modified polystyrene magnetic nanospheres for phthalate esters extraction from beverages.

The fabrication of novel poly(ionic liquids)-modified polystyrene (PSt) magnetic nanospheres (PILs-PMNPs) by a one-pot miniemulsion copolymerization reaction was achieved through an efficient microwave-assisted synthesis method. The morphology, structure, and magnetic behavior of the as-prepared magnetic materials were characterized by using transmission electron microscopy, vibrating sample magnetometry, etc. The magnetic materials were utilized as sorbents for the extraction of phthalate esters (PAEs) from beverage samples followed by high-performance ultrafast liquid chromatography analysis. Significant extraction parameters that could affect the extraction efficiencies were investigated particularly. Under optimum conditions, good linearity was obtained in the concentration range of 0.5-50 (dimethyl phthalate), 0.3-50 (diethyl phthalate), 0.2-50 (butyl benzyl phthalate), and 0.4-50 μg/L (di-n-butyl phthalate), with correlation coefficients R2  > 0.9989. Limits of detection were in the range 125-350 pg. The proposed method was successfully applied to determine PAEs from beverage samples with satisfactory recovery ranging from 77.8 to 102.1% and relative standard deviations ranging from 3.7 to 8.4%. Comparisons of extraction efficiency with PSt-modified MNPs as sorbents were performed. The results demonstrated that PILs-PMNPs possessed an excellent adsorption capability toward the trace PAE analytes.