Used as an intermediate in the synthesis of dyes and pigments, particularly for producing azo dyes with high color fastness. It improves solubility and stability in dye formulations. Also employed in the development of fluorescent whitening agents for textiles and paper. Plays a role in analytical chemistry as a derivatizing agent for detecting amines and amino acids. Its sulfonate groups enable use in water treatment as a dispersant for organic and inorganic particles.