Used primarily as a fluorescent derivatization reagent for the detection of nitrite and other nitrogen oxides in environmental and biological samples. It reacts with nitrite under acidic conditions to form a highly fluorescent compound, naphthotriazole, which can be measured using fluorometry or HPLC with fluorescence detection. This makes it valuable in monitoring nitrite levels in water, food products, and biological fluids like blood and urine. Also employed in analytical chemistry for the determination of nitric oxide in gaseous samples. Its high sensitivity and selectivity in fluorescence-based assays make it suitable for trace-level analysis. Additionally, it serves as a precursor in the synthesis of dyes, polymers, and pharmaceuticals due to its aromatic amine functionality.