Fabrication of functionalized magnetic microspheres based on monodispersed polystyrene for quantitation of allyl-benzodioxoles coupled with gas chromatography and mass spectrometry.

Monodispersed magnetic microspheres were synthesized by the magnetization of the aminized polystyrene cores and the subsequent polymerization of allyl glycidyl ether, divinylbenzene and N-vinyl-2-pyrrolidone, which exhibited excellent monodispersity in aqueous solution and high efficiency for allyl-benzodioxoles extraction. Various techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry (VSM) were employed to characterize the composites. Coupled with gas chromatography-mass spectrometry (GC-MS), a sensitive and simple magnetic solid phase extraction (MSPE) procedure based on the prepared microspheres was established for determination of allyl-benzodioxoles in cola-flavoured drinks. The factors affecting the extraction procedure, such as pH value, adsorbent amount, adsorption time, desorption solution and desorption time were optimized. The developed method was characterized by a high recovery (spiked at 5 μg L-1, 25 μg L-1 and 250 μg L-1), a low detection limit (0.05 μg L-1 for safrole and 0.08 μg L-1 for myristicin), a good linearity (correlation coefficients higher than 0.9990 for both) and a satisfactory repeatability (relative standard deviation below 3.7% for both, n = 3). The approach proposed here was confirmed to be fast and reliable for quantitative analysis of allyl-benzodioxoles in cola samples, especially at a trace level.