Solid phase extraction of bisphenol A using magnetic core-shell (Fe3O4@SiO2) nanoparticles coated with an ionic liquid, and its quantitation by HPLC

Core-shell nanoparticles (NPs) of the type Fe3O4@SiO2 were prepared, coated with 3 different ionic liquids, and tested for their capability of extracting bisphenol A (BPA). The results showed BPA is best extracted by NPs of the type Fe3O4@SiO2@[OMIM] (where OMIM stands for 1-octyl-3-methylimidazole hexafluorophosphate). Following desorption with methanol, BPA was quantified by HPLC with fluorescence detection in the UV. The following figures of merit were found under optimal conditions: A linear range from 0.5 to 2.0 x 104 mu g center dot LaEuro3/4(1), a detection limit of 90 ng center dot LaEuro3/4(1), a relative standard deviation of 1.2 % (for n = 3 and 10 mu g center dot LaEuro3/4(1)), and a pre-concentration factor of 25. The NPs can be re-used up to 10 times. The method was successfully applied to the determination of BPA in plastic tableware.