Used primarily in analytical chemistry for the detection and quantification of carbonyl compounds such as aldehydes and ketones. It reacts with these compounds to form nitrophenylhydrazones, which are often colored and easily detectable by spectrophotometric methods. This makes it valuable in pharmaceutical analysis and quality control for identifying impurities or degradation products in drugs. Also employed in the synthesis of dyes and heterocyclic compounds due to its reactivity as a hydrazine derivative. Handle with care due to its potential toxicity and sensitivity to heat and shock.