DIFFERENTIAL DETERMINATION METHODS OF Cu²⁺ AND Zn²⁺ IONS BASED ON SPECTROSCOPIC PARAMETERS (λmax, ε).

Abstract

 Accurate and selective determination of transition metal ions is of significant importance in analytical chemistry due to their essential biological roles and environmental relevance. In this work, differential spectroscopic approaches were developed for the identification of Cu²⁺ and Zn²⁺ ions based on their characteristic absorption parameters, namely the wavelength of maximum absorption (λ_max) and molar absorptivity (ε). Experimental studies revealed that Cu²⁺ ions exhibit pronounced d–d transitions in the visible region, producing distinct absorption maxima and relatively high molar absorptivity values, while Zn²⁺ ions, as a d¹⁰ system, lack d–d transitions and are instead characterized by weaker ligand-to-metal charge-transfer bands in the ultraviolet region. Comparative analysis of spectral parameters allowed reliable differentiation of these ions, even in mixed solutions. The proposed methodology demonstrates high sensitivity, reproducibility, and analytical selectivity, making it suitable for practical applications in environmental monitoring, water quality assessment, and industrial effluent analysis.