Development of magnetic dispersive solid phase extraction of Cd(ii) ions from dairy products using an Fe3O4@ZIF-8@IIP nanocomposite sorbent

Abstract

Based on dispersive micro solid phase extraction, a magnetic ion imprinted polymer–metal organic framework (Fe₃O₄@ZIF-8@IIP) nanocomposite was prepared in this work as a selective and effective sorbent to extract and preconcentrate cadmium(II) ions in dairy samples. An effective extraction process was made possible by the magnetic properties of iron oxide nanoparticles, metal–organic framework's large specific surface area, and ion imprinted polymer's selectivity toward Cd(II) ions. Fourier transform infrared spectrometry and scanning electron microscopy were used to characterize the produced sorbent. Effective optimization factors were examined and optimized, including the volume and type of desorption solvent, the type and duration of stirring, the pH of solution, and the quantity of the sorbent. The limits of detection and quantification under optimal extraction conditions were 0.09 and 0.30 μg L⁻¹, respectively. The linear range, which was 0.30–100 μg L⁻¹, had a coefficient of determination of 0.9927. A satisfactory match was observed in the data collected after testing a certified reference material (NIST SRM 1549 powder milk) to verify the established procedure. When Cd(II) ions were determined at 10 μg L⁻¹ (n = 5), the approach produced relative standard deviation values of ≤3.1%. The developed technique was effectively used to determine Cd(II) ions concentration in several dairy products.