Used as a sensitive indicator in complexometric titrations, particularly for detecting metal ions such as zinc, lead, bismuth, and rare earth elements. It forms highly colored complexes with these metals, shifting from yellow to red or violet at the endpoint, making it ideal for EDTA titrations. Also employed in spectrophotometric analysis to quantify metal concentrations in environmental, biological, and industrial samples. Its high selectivity in acidic to weakly acidic conditions makes it valuable in analytical chemistry for precise metal ion determination.