Used as a colorimetric indicator in complexometric titrations, particularly for the detection of trivalent metal ions such as iron (Fe³⁺), aluminum (Al³⁺), and chromium (Cr³⁺). It is especially effective in acidic to slightly acidic pH conditions where it forms stable, intensely colored complexes with these metals, changing color from yellow to red or violet upon binding. Commonly employed in EDTA titrations when direct or back-titration methods are applied to determine metal ion concentration in analytical chemistry. Also utilized in environmental testing and industrial quality control for metal ion analysis in water and chemical samples.