Utilization of hydrazide-based silica sorbent for ultrasound-assisted dispersive micro solid phase extraction of some heavy metals in water, milk, and fruit juice

In this study, (E)-N’((2-butyl-4-chloro-1H-imidazol-5-yl)methylene)isonicotinohydrazide was first synthesized, and this ligand was supported on the silica surface. The obtained hydrazide-based sorbent was used for ultrasonic-assisted dispersive micro solid phase extraction of Co(II), Cd(II), Ni(II), Pb(II), and Zn(II). The metal ions after extraction were analyzed by flame atomic absorption spectrometry. For the optimization of the method, parameters such as ligand concentration, type and volume of elution solvent, pH of sample solution, amount of sorbent, and extraction time were optimized in this study. Under the determined optimum conditions for all metal ions, the extraction recovery was ˃95 %. In the optimum conditions, the linear range was 5–500 µg L for Co(II), Pb(II), Zn(II), 10–500 µg L⁻¹ for Cd(II) and Ni(II). The limit of detections obtained for Co(II), Cd(II), Ni(II), Pb(II), and Zn(II) were 1.48, 2.97, 3.17, 1.62, and 1.55 µg L⁻¹, respectively. The preconcentration coefficient for all metal ions was obtained as 40. Intra-day and inter-day relative standard deviation values (between 1.22 % and 3.53 %) determined with 10 and 50 µg L⁻¹ metal concentrations showed that the results were repeatable. The suggested method was successfully performed on two different water, milk, and fruit juice samples.