Rapid screening plate of cadmium-chelating activity based on a quaternary complex of Cd(II)-Chrome azurol S CAS-2,2′-dipyridyl dipy-cetylpyridinium bromide CPB

Heavy metal ions, such as Cd, Hg, Pb, and As, tend to persist in soil without natural degradation and can be absorbed by crops, leading to the accumulation of agricultural products that pose a significant threat to human health. However, the development of a rapid and efficient technique for identifying heavy metals in agricultural products is essential to ensure health and safety. With the knowledge of the extent of damage caused by heavy metals, it becomes imperative to detect the presence of cadmium in the soil, water, and the environment. This study introduces a novel plate approach for quick and precise colorimetric detection of cadmium ions using the Cd(II)-Chrome Azurol S CAS-2,2′-dipyridyl dipy-Cetylpyridinium Bromide CPB quaternary complex. Our innovative method has shown that at a reaction solution pH of 11, the optimal concentration ratio is CAS (5 × 10⁻³ M): dipy (0.1 M): CPB (1.0 × 10⁻³ M) = 4 mL: 1 mL: 1 mL. The most significant fading alert was observed when the ethylenediaminetetraacetic acid (EDTA) chelator was added dropwise to the CAS detection plate, indicating strong chelation of Cd by EDTA. This laboratory-based study established a foundation for future applications in real environmental sample analysis.