Used as a colorimetric reagent for the determination of metal ions, particularly in analytical chemistry. It forms highly colored complexes with metals like zinc, cadmium, magnesium, cobalt, nickel, and copper, enabling their detection and quantification in various samples via spectrophotometry. Applied in environmental testing to monitor water quality by identifying trace metal contaminants. Also utilized in biochemical research for studying metal ion interactions with proteins and enzymes. Its sensitivity and selectivity make it valuable in laboratory analysis and industrial quality control processes.