Used in analytical chemistry as a reagent for the detection and determination of certain metals, particularly cobalt and nickel, due to its ability to form colored complexes. It also serves as an intermediate in the synthesis of dyes and pharmaceuticals, where its functional groups allow for further chemical modifications. Its nitroso and carboxylic acid groups contribute to chelating properties, making it useful in studies involving metal ion coordination. Additionally, it has been explored in research related to antioxidant and antimicrobial activity, showing potential for application in medicinal chemistry.