Determination of Mn(II) ions in soil samples by means of a sensitive sorption-spectroscopic method

Manganese (Mn(II)) is an essential micronutrient but becomes toxic at elevated concentrations, posing significant risks to human health and ecosystems. Current methods for detecting Mn(II) in environmental samples often lack sensitivity, selectivity, or cost-effectiveness. Addressing these limitations, this study focuses on developing a sensitive and efficient sorption-spectroscopic method for Mn(II) determination in soil and water samples. The need for a reliable, low-cost, and high-performance analytical technique to monitor Mn(II) levels in contaminated environments is critical for environmental and public health protection. (88 words) RESULTS: We immobilized nitroso-R-salt onto a polyethylene polyamine-modified polyacrylonitrile (PPF) fibrous sorbent, creating a highly efficient matrix for Mn(II) detection. The method exhibited a linear detection range of 5-50 mg L^-1, a detection limit of 0.003 mg L^-1, and an adsorption efficiency of 96-97 %. Optimal conditions included a pH of 3-4 and a maximum absorption wavelength of 500 nm. Quantum chemical calculations confirmed the stability of the nitroso-R-salt/PPF complex and its interaction with Mn(II). The method was validated using soil samples from industrial zones, showing strong agreement with ICP-MS results (R² = 0.9979). (125 words) SIGNIFICANCE: This work presents a novel, cost-effective, and highly sensitive sorption-spectroscopic method for Mn(II) detection, overcoming limitations of conventional techniques. Its applicability to real-world environmental samples and strong correlation with standard methods underscore its potential for widespread use in monitoring Mn(II) contamination, contributing to better environmental management and public health safeguards. (50 words).