Rapid Magnetic Solid-Phase Extraction Based on Graphene Oxide/Magnetite Nanoparticles for the Determination of Non-Steroidal Anti-Inflammatory Drugs and Bisphenol-A in Tap Water

A simple and rapid magnetic solid-phase extraction based on reduced graphene oxide/ferroferic oxide (rGO/Fe3O4) coupled with high performance liquid chromatography-diode array detector (HPLC-DAD), was proposed for the determination of naproxen and diclofenac sodium of non-steroidal anti-inflammatory drugs (NSAIDs) and bisphenol-A residue in tap water sample. Fe3O4 was assembled with graphene oxide by facile method. Several important parameters, such as extraction time, desorption time and desorption solvent were studied and optimized. Optimal conditions were then used for the extraction of NSAIDs and bisphenol-A from real samples, prior to HPLC-DAD analysis using C18 column. The proposed method provides good linearity in the range of 1.0-5.0 mg L-1 (R2 naproxene = 0.9983, R2 diclofenac = 0.9960) for NSAIDs and R2 = 0.9919 for bisphenol-A; limit of detection of 0.031 mg L-1 and 0.023 mg L-1 for naproxen and diclofenac, respectively and 0.1785 mg L-1 for bisphenol-A; limit of quantification for naproxen and diclofenac were 0.102 and 0.076 mg L-1, respectively and 0.5949 mg L-1 for bisphenol-A; relative recoveries between 66.21 and 105.60 % for diclofenac and naproxen, respectively and 72.74 % for bisphenol-A; and acceptable reproducibility relative standard deviation (RSD, n = 3) of 6.79 and 11.32 % for diclofenac and naproxen, respectively and 0.93 % for bisphenol-A. The method was successfully applied to tap water sample and the results indicates that small residue of bisphenol-A is present the sample while no traces of NSAIDs was detected.