DEVELOPMENT OF SORPTION-SPECTROPHOTOMETRIC DETERMINATION OF COBALT IONS IN ENVIRONMENTAL OBJECTS

Abstract

The complexation of cobalt(II) ions with immobilized 4-((2-hydroxy-3-nitroso-1-naphthyl)azo)benzenesulfonic acid (HNNBSA) on a synthesized polyacrylonitrile sorbent (PPD). Optimal conditions for immobilization of the reagent and complexation with cobalt ions have been established. The analytical properties of the immobilized reagent were studied by spectrophotometric, spectroscopic, X-ray fluorescence and scanning electron microscopy methods. It is established that the analytical procedure based on the HNNBSA–PPD system is characterized by high selectivity, accuracy and reproducibility. The maximum spectral signals of the immobilized reagent and its complex with cobalt(II) ions are observed at 475 and 575 nm, respectively. The detection limit of cobalt is 0.02 μg/mL. The developed method is characterized by simplicity of sorbent regeneration and high expressiveness and can be used to determine cobalt ions in environmental objects.