Investigation of the physicochemical properties of Alizarin Red S-immobilized sorbent for the determination of Zn(II) ions

Abstract

The development of efficient sorption materials for the selective determination of metal ions remains an important area of analytical chemistry and environmental monitoring. In the present study, the physicochemical properties of an Alizarin Red S-immobilized sorbent were investigated with the aim of evaluating its suitability for the determination of Zn(II) ions in aqueous media. Alizarin Red S, a widely used chromogenic reagent containing hydroxyl and sulfonic functional groups, was immobilized onto a solid support to obtain a stable sorption system with enhanced analytical performance. The prepared sorbent was characterized using physicochemical and spectroscopic methods to assess its structural features, surface properties, and interaction mechanisms with Zn(II) ions. Particular attention was given to the influence of immobilization on the functional groups of the reagent and the stability of the resulting sorbent. The sorption behavior of Zn(II) ions was investigated under different experimental conditions, including solution pH, contact time, and initial metal ion concentration. The sorption efficiency and analytical characteristics of the immobilized system were also evaluated. The results demonstrated that immobilization of Alizarin Red S onto the solid matrix produced a chemically stable sorbent possessing a high affinity toward Zn(II) ions. The sorption process was strongly influenced by the acidity of the solution, with maximum sorption observed in the weakly alkaline medium. The immobilized reagent retained its complex-forming ability and exhibited favorable physicochemical characteristics, including good stability, reproducibility, and sorption capacity. Spectroscopic investigations confirmed the participation of hydroxyl and carbonyl functional groups in the formation of Zn(II)-Alizarin Red S complexes on the sorbent surface. The obtained findings indicate that the Alizarin Red S-immobilized sorbent can serve as an effective material for the preconcentration and determination of Zn(II) ions. The combination of selective complex formation, high sorption efficiency, and favorable physicochemical properties makes the developed sorbent a promising analytical tool for environmental, industrial, and laboratory applications involving zinc ion determination.