Double-functionalised magnetic nanoparticles for efficient extraction of bisphenol A from river water

Environmental context Conventional pre-treatment methods are usually ineffective for the extraction of bisphenol A (BPA) from environmental water samples. We report that a novel magnetic nanoparticle with double-functionalisation is an excellent solid-phase adsorbent for extracting BPA from river water samples. This study provides a simple but efficient approach for extraction of low-concentration pollutants from water samples. Abstract In this study, double functionalised magnetic nanoparticles (DFMNPs) for extraction of bisphenol A (BPA) in an aqueous phase were designed and prepared. In the preparation of DFMNPs, amide and pyridine groups were simultaneously introduced into the surface of magnetic nanoparticles. A new dispersed solid-phase extraction (DSPE) method adopting DFMNPs as the adsorbents was developed for separating and enriching BPA from river water samples. This DSPE method showed fast magnetic response, high binding efficiency to target BPA, and short experimental time. The recovery of BPA in spiked river water was 94.4% with the DSPE method, which was much higher than those with traditional solid-phase extraction (SPE) methods. The high performance of DFMNPs on extraction of BPA from river water was attributed to the synergistic function of the amide and pyridine groups. The hydrophilic amide groups caused DFMNPs to disperse well in water, whereas the alkaline pyridine groups bound BPA effectively by ionic bonds. Our DSPE was particularly superior to conventional SPE in the pre-treatment of large-volume water samples as the time taken could be remarkably reduced.