Optimization of vortex-assisted magnetic nanofluid based liquid phase microextraction for fast, green and reliable extraction of ibuprofen from real samples: Multivariate approach

In this research, the vortex-assisted magnetic nanofluid based liquid phase microextraction (VA-MNF-LPME) procedure was optimized using Box–Behnken Design (BBD) for the selective and reliable extraction of ibuprofen from aqueous solutions. Three MNFs were prepared and tested for the selective extraction of ibuprofen. Ultraviolet–visible spectrophotometry (UV–Vis) was used to determine the amount of ibuprofen and measurements were made at a wavelength of 238 nm. The effects of pH, MNF volume, vortex time, volume of back extraction solvent were optimized using BBD. Separation of the MNF phase containing the ibuprofen in aqueous solution was achieved using a neodymium magnet without the need for centrifugation step. Using optimized parameters (pH = 3.4, 690 μL of MNF, 100 s vortex and 230 μL of ethanol), the detection limit and working range of the V-MNF-LPME procedure were 0.6 ng mL−1 and 2–180 ng mL−1, respectively. Relative standard deviations and recovery (for 25 ng mL−1 of ibuprofen solution, N = 5) were 2.8% and 94.1%. Key validation parameters of the method were studied in detail and calculated under optimized conditions. The VA-MNF-LPME procedure was successfully applied to some drugs, baby lettuce and grape leaf samples in ten stages with a standard-addition approach, and quantitative recoveries were obtained (91.4–98.7%).