Application of deep eutectic solvent functionalized cobalt ferrite nanoparticles in dispersive micro solid phase extraction of some heavy metals from aqueous samples prior to ICP-OES

In this study, a simple and sensitive analytical method was developed for the determination of some heavy metal ions in aqueous samples using inductively coupled plasma-optical emission spectrometry. In this method, firstly, cobalt ferrite nanoparticles were synthesized before they were functionalized with a deep eutectic solvent. The used functionalization solvent was prepared by mixing choline chloride and p-aminophenol. The obtained new nanoadsorbent was used for the extraction of Zn(II), Ni(II), Cu(II), Pb(II), and Hg(II) from the sample solutions by dispersive micro solid phase extraction. The effect of some important parameters such as the sorbent amount, ionic strength, pH, agitation mode and time, and elution solvent type and volume on the extraction efficiency of the method was investigated. Broad linear ranges (1.83–200 ng mL−1) with low limits of detection in the range of 0.54–1.3 ng mL−1 were obtained. The accuracy of the developed method was investigated by determination of the analytes in a certified reference material (SPS-WW2 Batch 108 water). The extraction recoveries of the analytes were obtained in the range of 72–90%. Finally, the developed method was successfully applied to determine the selected ions in different water and fruit juice samples, and the relative recoveries were obtained in the range of 85–104%.