Used as a derivatizing agent in analytical chemistry to detect and quantify carbonyl compounds such as aldehydes and ketones. It reacts with carbonyl groups to form hydrazone derivatives, which are often crystalline and suitable for identification by melting point analysis or chromatography. Commonly applied in the determination of keto sugars and steroids. Also employed in the synthesis of heterocyclic compounds and dyes. Its nitro group allows for easy detection by UV-Vis spectroscopy, enhancing sensitivity in assay methods.