A nanohybrid composed of polyoxotungstate and graphene oxide for dispersive micro solid-phase extraction of non-steroidal anti-inflammatory drugs prior to their quantitation by HPLC.

A nanohybrid was prepared from polyoxotungstate anion and graphene oxide (POT/GO) and characterized in terms of porosity by applying Fourier transform infrared and transmission electron microscopy. The nanohybrid was applied as a sorbent for the dispersive micro solid-phase extraction of the non-steroidal anti-inflammatory drugs (NSAIDs) ibuprofen, diclofenac, and naproxen. Different types of sorbents were compared, and the POT/GO nanohybrid was found to have the best adsorption affinity. The NSAIDs were quantified via HPLC with UV detection. Under the optimum conditions, the limits of detection (at an S/N ratio of 3) range between 0.02-0.03 ng.mL, and the linear response ranges extend from 0.08-200 ng.mL, respectively. The relative standard deviations (RSDs) for five replicates at three concentration levels (0.1, 5 and 100 ng.mL) of NSAIDs ranged from 4.1 to 6.1%. The applicability of the method was confirmed by analyzing spiked real water samples, and satisfactory results were obtained, with recoveries between 95.6 and 99.6%. Graphical abstract Schematic representation of the polyoxotungstate/graphene oxide nanohybrid preparation.