Used as an analytical reagent for the detection and determination of metal ions, particularly in spectrophotometric analysis. It acts as a selective chromogenic reagent, forming stable, colored complexes with certain transition metals, which allows for sensitive measurement in environmental and industrial samples. Its structure enables strong chelation with metals like copper and nickel, making it useful in qualitative and quantitative metal assays. Also applied in research for developing sensors and in studies involving coordination chemistry due to its distinct color change upon metal binding.