Magnetic multi‐walled carbon nanotubes as a valuable option for the preconcentration of non‐steroidal anti‐inflammatory drugs in water

Abstract

AbstractWater bodies receive a high discharge of drugs, which can behave as pollutants. Sample preparation with new materials and techniques are necessary to achieve adequate selectivity and sensitivity for the determination of these compounds in waters. In this work, magnetic nanoparticles modified with pristine multi‐walled carbon nanotubes have been used as sorbents in a magnetic solid‐phase extraction method for the determination of ibuprofen, naproxen and diclofenac in natural waters. The synthesis and functionalization of the sorbent are achieved in one single step. Liquid chromatography with ultraviolet and fluorescence detectors was used after sample preparation. The main factors that affect the adsorption and desorption were optimized. Limits of detection were 6.0–9.8 μg L−1 and precision was 1.3–6.1% relative standard deviation. The enrichment factors (4.1–4.8) were close to the preconcentration factor (5) with an amount of sorbent as low as 2.5 mg. Extraction recoveries of 81.3–101.5% were obtained in spiked tap, river and dam water samples. The low amount of adsorbent used and its reusability (up to five times) offers a high economy of use and low waste generation.