Separation and Spectral Determination of Cd(II) as a Chelation Complexes in Aqueous Solution and Food Samples by Using 4-((4-hydroxyquinolin-3-yl) diazenyl) benzene sulfonamide and 3-((1H-indol-5-yl) diazenyl )quinolin-4-ol

Abstract

This study reports on a cloud point extraction (CPE) method devised for the thorough separation, preconcentration, and spectrophotometric estimation of cadmium (Cd(II)) from solutions and food matrices using azo derivatives as complexing agents. The research problem under study concerns the sensitive and selective determination of Cd(II), a heavy metal recognized as toxic due to its profound environmental and health dangers. The specific aim was to optimize and check CPE method reproducibility for the more stable chelation complexes of cadmium (II) 4-((4-hydroxyquinolin-3-yl)diazenyl)benzenesulfonamide (HQDBS) and 3-((1H-indol-5-yl)diazenyl)quinolin-4-ol (IDQ). The optimization was performed by testing the following fundamental parameters: pH, type and volume of surfactant (Triton X-100), extraction temperature, and duration of heating. The maximum absorptions (λmax) of both examined complexes of cadmium with HQDBS and IDQ were found at 478 nm and 499 nm respectively. The spectroscopic methods and field emission scanning electron microscopy (FE-SEM) were applied to structural characterization of the extracted complexes. The developed method was applied to food samples and validated with Flame Atomic Absorption Spectroscopy (FAAS). It was showed that the methods gave highly sensitive and good selective responses which had a strong correlation with the FAAS results. F-test statistical calculations showed that the differences between techniques are insignificant, thus proving the reliability of CPE methodology expected for Cd(II) analytical chemistry. The CPE technique is recommended for determining the presence of Cd(II) in food and environmental samples since it is easy, economical, and less harmful to the environment.