Widely used as a sensitive indicator in complexometric titrations for the detection of copper ions. It forms a stable, colored complex with copper, showing a distinct color change from blue to red or pink at the endpoint, making it highly effective for trace copper analysis. Commonly applied in water quality testing, pharmaceutical analysis, and industrial process control where precise determination of copper content is required. Its selectivity for copper in the presence of other metal ions enhances its reliability in mixed-metal systems, especially when combined with masking agents. Suitable for use in slightly acidic to neutral pH ranges, it is preferred in titrations involving EDTA or similar chelating agents.