Utilizing nanoflower-like NiFeO for dispersive micro solid phase extraction of copper at ultratrace level in food and water samples.

Nanoflower-like NiFeO (NFO-NF) was synthesized and employed to develop a dispersive micro solid phase extraction procedure for copper. NFO-NF was characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning transmission electron microscopy (STEM), scanning electron microscopy-dispersive X-ray spectroscopy (SEM-EDX), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD). The optimal conditions for experimental parameters were pH: 8.0, adsorbent dose: 2 mg, both adsorption and desorption times: 60 s, sample volume: 30 mL, and eluent: 1.0 mL of 1.0 mol L HNO₃. An effective enrichment factor (30-fold) for copper was obtained. The limit of detection and limit of quantitation of Cu (II) were 2.1 μg L, 8.5 μg kg and 7.0 μg L, 25.4 μg kg for water and food samples, respectively. The suggested method's accuracy was verified by certified reference materials with recoveries of higher than 90 %. The copper content of food and water samples was successfully determined by using presented method.