TITLE:
The Extractive Spectrophotometric Determination of Cu(II) Ions in Environmental and Industrial Samples
AUTHORS:
Todjiyev Jamoliddin, Turaeva Gulzoda, Turabov Nurmukhammat, Khayrullayeva Shahinabonu, Kholiyorova Rano, Tuliev Bekhruz
KEYWORDS:
Extractive Spectrophotometry, Copper(II), Organic Analytical Reagents, Chromogenic Ligands, Complex Formation, Liquid-Liquid Extraction, Trace Metal Analysis, Environmental Monitoring, Green Chemistry
JOURNAL NAME:
Open Access Library Journal,
Vol.13 No.5,
May
22,
2026
ABSTRACT: This review article summarizes and analyzes modern approaches to the extractive spectrophotometric determination of copper(II) ions in natural waters, ores, environmental, and industrial samples. The quantitative determination of Cu(II) ions is of great importance for scientific and medical research, as well as for environmental monitoring. In recent years, numerous methods have been developed to ensure high accuracy, rapid analysis, and high sensitivity in their determination. Particular attention has been devoted to the development and application of organic analytical reagents capable of forming intensely colored, stable, and selectively extractable complexes with Cu(II) ions. The paper discusses the physicochemical properties, environmental behavior, and toxicological significance of Cu(II) ions, emphasizing the necessity of their sensitive and selective monitoring in natural waters, wastewater, soils, food products, and pharmaceutical samples. In addition, the historical development of organic reagents in inorganic analysis and the role of coordination chemistry in advancing spectrophotometric methods are also highlighted. A wide range of chromogenic reagents-including hydrazones, thiosemicarbazones, azo compounds, triazoles, and Schiff bases-is reviewed. For each system, key analytical characteristics such as optimal pH, complex stoichiometry, extraction conditions, absorption maxima (λmax), molar absorptivity (ε), linear dynamic ranges, limits of detection, limits of quantification, stability constants, and interference effects are comparatively analyzed. The advantages of extractive spectrophotometry-high sensitivity, simplicity, cost-effectiveness, and applicability to trace-level determination-are highlighted in comparison with instrumental techniques such as atomic absorption spectrometry. Overall, spectrophotometric techniques stand out among analytical methods due to their high precision, rapid operation, and low reagent consumption, making them effective tools in environmental and biomedical research.