One‐step hydrothermal synthesis of magnetic nitrogen‐doped graphene for magnetic solid‐phase extraction of nonsteroidal anti‐inflammatory drugs in environmental water samples

Abstract Graphene oxide has received extensive attention because of its unique properties and potential applications. In this study, magnetic nitrogen‐doped graphene was prepared by one‐step hydrothermal reaction using urea as the dopant and reductant, and ferroferric oxide nanoparticles were in situ deposited on the surface of the nanohybrids. The magnetic nitrogen‐doped graphene was characterized using various physical and chemical methods. It was used as a new adsorbent for the magnetic solid‐phase extraction of four nonsteroidal anti‐inflammatory drugs from the river water. The parameters influencing the extraction efficiency were optimized in detail. Under optimal conditions, this method provided a wide linear range (5–200 ng/mL). The limits of detection were in the range of 1.07–5.10 ng/mL. The recoveries varied from 81.2 to 121.5% with relative standard deviations of less than 10.8%. Overall, we can conclude that the proposed method offers an efficient pretreatment and enrichment and can be successfully applied for the extraction and determination of nonsteroidal anti‐inflammatory drugs in complex matrices.