Ferrozine mono-sodium salt hydrate is widely used as a sensitive chromogenic reagent for the detection and quantification of iron ions, especially Fe²⁺, in various samples. It forms a stable magenta-colored complex with ferrous ions, which can be measured spectrophotometrically at 562 nm, enabling precise determination of iron concentration in environmental, biological, and industrial samples. It is commonly applied in assays to measure iron content in serum, cellular extracts, and pharmaceuticals due to its high selectivity and sensitivity. The reagent is also used in studies of iron metabolism, oxidative stress, and metal chelation. Additionally, it helps in monitoring iron contamination in water and food products. Its ability to form water-soluble complexes makes it suitable for use in aqueous-based analytical procedures without the need for organic solvents.