Optimizing Liquid-Liquid Extraction of Nickel (II) Ions with Azo Derivatives: Analytical Applications and Insights

A liquid-liquid extraction study was conducted to investigate the extraction of nickel (II) ions using the chelating agent 2-[(2,6-dimethylphenyl)azo]-4,5-diphenylimidazole (2,6-DMPADPI). The study explored various factors influencing the extraction percentage and extraction coefficient, including equilibrium time, metal concentration, acidic medium, types of solvents, batch extraction methods, leaching processes, and the effects of positive and negative ions. The optimal conditions for extraction were determined to be an acidity index of 9, an extraction time of 10 minutes, and a temperature of 298 K. Thermodynamic functions (∆G, ∆H, ∆S) were calculated, demonstrating that the extraction reaction is exothermic, spontaneous, and accompanied by an increase in randomness. Additionally, UV-Visible and infrared spectroscopy (FT-IR) studies were performed on the chelating agent to characterize its properties. The study also examined some physical properties of the resulting complex and assessed its specific conductivity. These findings contribute valuable insights into the efficient extraction of nickel (II) ions using 2,6-DMPADPI.