Used primarily as a fluorescent reagent for the detection and quantification of nitrite in environmental and biological samples. When reacted with nitrite under acidic conditions, it forms a highly fluorescent compound called naphthotriazole, which can be measured using fluorometry. This makes it valuable in water quality testing, where monitoring nitrite levels is essential for assessing pollution and ensuring safe drinking water. It is also applied in biochemical research to study nitrogen metabolism and in analytical chemistry for trace analysis of nitrosating agents. Due to its sensitivity, it is effective at detecting low concentrations of nitrite in complex matrices.