Deep eutectic solvent-modified magnetic NiFe₂O₄ polyamidoamine dendrimers for the simultaneous separation and extraction of naproxen and nabumetone and determination by HPLC: isotherm and thermodynamic study

A novel dispersive magnetic micro-solid-phase extraction (DM-µ-SPE) method based on the magnetic NiFe₂O₄ polyamidoamine dendrimers modified with deep eutectic solvent sorbent has been developed for the extraction of naproxen and nabumetone. The extracted analytes were quantified by a high-performance liquid chromatographic (HPLC) method with UV detection at 280 nm. The linearity was in the range of 1–400 µg L⁻¹ for naproxen and 3–400 µg L⁻¹ for nabumetone. The developed DM-µ-SPE/HPLC–UV method has been characterized by excellent intra- and inter-day repeatability of 2.3, 3.3, and 2.5, 4.0%, respectively, for naproxen and nabumetone at the concentration level of 70.0 µg L⁻¹ (n = 5). Enhancement factors of 157.7 and 151.8 and limit of detections of 0.15 µg L⁻¹ and 0.26 µg L⁻¹ for naproxen and nabumetone were achieved, respectively. The sorption isotherm study illustrated that the experimental data of NAP fitted better to the Langmuir isotherm with a maximum monolayer sorption capacity of 76.92 mg g⁻¹, while the NAB data fitted to the Temkin isotherm model. The method was successfully applied to the determination of non-steroidal anti-inflammatory drug analytes in water and milk samples.