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

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.