Magnetic solid phase extraction of non-steroidal anti-inflammatory drugs from water samples using a metal organic framework of type Fe3O4/MIL-101(Cr), and their quantitation by UPLC-MS/MS

The authors describe a method for magnetic solid phase extraction (MSPE) combined with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the quantitation of eight non-steroidal anti-inflammatory drugs (NSAIDs) in wastewater and environmental water samples. Specifically, the NSAIDs were directly extracted by using a magnetic nanocomposite of type Fe 3 O 4 /MIL-101(Cr) (Matérial Institute Lavoisier, MIL) from 50 mL water samples without any further cleanup. The effects of the amount of adsorbent, pH value, salt concentration, ultrasonic extraction time, desorption solvent nature and volume and desorption time were investigated. Under the optimal conditions, UPLC-MS/MS based detection resulted in the following figures of merit: (a) Linear calibration plots that typically extend from 0.1 (0.2, 0.05, 0.02) to 50 μg·L −1 , depending on the compound; (b) detection limits between 3 to 60 ng·L −1 ; and (c), recoveries varying from 81.2% to 116.8% with relative standard deviations between 0.4% and 10.8%. The adsorption of NSAIDs on Fe 3 O 4 /MIL-101(Cr) was characterized by adsorption isotherms, kinetics and thermodynamics studies and provides a deeper insight into the adsorption mechanism. Compared to other method for pretreatment and preconcentration of NSAIDs, the new method is more rapid, sensitive, accurate and eco-friendly. The method was successfully applied to the determination of the NSAID residues in a variety of real environmental and wastewater samples. Schematic of a method for determination of non-steroidal anti-inflammatory drugs (NSAIDs) in environmental water by magnetic solid phase extraction based on Fe 3 O 4 /MIL-101(Cr) combined with UPLC-MS/MS. The adsorption mechanism of NSAIDs on Fe 3 O 4 /MIL-101(Cr) was studied.