Separation, Extraction and Spectrophotometric Determination of Palladium(II), Iridium(III) and Ruthenium(III) from Alloys Assisted by ۲-(۲-(۱-(Thiophene-۲-yl) Ethylidene) Hydrazinyl) Benzoic Acid

A novel extractive spectrophotometric method has been developed for the determination of palladium(II), iridium(III), and ruthenium(III) using ۲-(۲-(۱-(thiophene-۲-yl) ethylidene) hydrazinyl) benzoic acid (TEHBA) as a selective complexing agent. In acidic medium palladium(II), iridium(III), and ruthenium(III) react with ۲-(۲-(۱-(thiophene-۲-yl) ethylidene) hydrazinyl) benzoic acid (TEHBA) and form stable complexes that are quantitatively extracted into a suitable extracting solvent. The absorption spectrum of these complexes was taken in the wavelength range of ۲۰۰-۴۰۰ nm. Beer’s law is obeyed between the concentration range ۲-۲۰ μg mL-۱, ۱۰-۶۰ μg mL-۱ and ۱۰-۵۰ μg mL-۱ in the final solution of palladium(II), iridium(III) and ruthenium(III) subsequently. Molar absorptivity and Sandel’s sensitivity values were also calculated for respective metal ions. The stoichiometry of the Ir(III)-TEHBA and Ru(III)-TEHBA complexes was computed as ۱:۱. However, the ratio of the Pd(II)-TEHBA complex was calculated as ۱:۲ by using the mole ratio method. These metal to ligand complexes are highly stable and selective, showing negligible interference from common metal ions even in a large excess. The unique binding properties of the ligand and the observed metal-ligand stoichiometry, supported by UV-Visible spectral analysis, reveal new insights into these complexes' electronic interactions and geometry. The high selectivity and stability of these systems underscore their potential for practical use in analytical and environmental chemistry. Developed methods offer low-cost, sensitive, and reproducible approach for Pd(II), Ir(III), and Ru(III) quantification in environmental synthetic samples. Additionally, the developed procedures illustrate a sequential extraction and separation of palladium(II), iridium(III) and ruthenium(III) and boast their simplicity of use.

کلیدواژه ها:

Solvent extraction ، Sequential separation ، UV-visible spectrophotometry ، TEHBA