Used as a sensitive metal ion indicator in complexometric titrations, particularly for the detection of trivalent metal ions such as aluminum, iron, and chromium. It forms stable, colored complexes with these metals, showing a distinct color change from yellow to red or violet at the endpoint. Commonly employed in EDTA titrations where precise detection of metal ion concentration is required. Also utilized in analytical chemistry for trace metal analysis in environmental and industrial samples due to its high selectivity and visibility of color transition.