Magnetic nanoparticles embedded with commercial sorbents as a smart approach for the determination of sulfonamides in water.

Magnetic solid phase extraction with a sorbent nanocomposite made of magnetic nanoparticles (MNPs) embedded in a commercial styrene-divinylbenzene polymeric sorbent (ExtraBond EBH™) is proposed, for the first time, in the extraction and preconcentration of four sulfonamides from different types of water. The importance of using commercial sorbents is that it avoids tedious and complicated synthetic processes and enables intercomparison and harmonization of results. The extraction was carried out with 4 mg of nanocomposite, and assisted by sonication for 1 min. The back-extraction was with 200 μL of methanol for 1 min by sonication, too. The subsequent determination was by liquid chromatography and ultraviolet detection. The limits of detection and quantification were 1.4-3.8 μg L-1 and 4.8-12.6 μg L-1, respectively, with enrichment factors from 5.8 to 13.9. The method was applied to tap and river waters with different salinity and organic matter. The method was considered safe and green enough as well as practical by recently published metrics.