Used primarily as a derivatizing agent in analytical chemistry, especially for the detection and quantification of amines and amino acids. Its high reactivity toward primary and secondary amines allows it to form stable sulfonamide derivatives, which are easily detectable by UV-Vis or fluorescence spectroscopy due to the nitro-aromatic chromophore. Commonly employed in HPLC analysis to enhance sensitivity and separation efficiency. Also utilized in the synthesis of dyes and pharmaceutical intermediates where selective sulfonation is required. Due to its moisture sensitivity, it is typically handled under anhydrous conditions in controlled environments.