24dinitrophenylhydrazin

2,4-Dinitrophenylhydrazine, commonly abbreviated DNPH, is an organic compound consisting of a hydrazine moiety attached to a 2,4-dinitrobenzene ring. It exists as the free base or, more commonly, as the hydrochloride salt, which offers greater stability for laboratory use. The compound is a yellow to orange solid that is sensitive to heat and shock.

In analytical chemistry, DNPH is used as a derivatizing reagent for carbonyl compounds. Aldehydes and ketones react with DNPH in acidic media to form hydrazone derivatives, which are typically colored and can be detected by UV-visible spectroscopy or separated by chromatography. This DNPH-based test is widely employed to identify and quantify carbonyl groups in a range of samples, including foods, environmental materials, and biological specimens.

Preparation and handling: DNPH is sold commercially, often as the hydrochloride salt. In the lab, DNPH solutions are prepared under acidic conditions and used promptly due to limited stability of the reagent in some media. It is incorporated into various spectrophotometric, TLC, or chromatographic workflows to assess carbonyl contents.

Safety: DNPH is toxic and acts as an irritant to skin, eyes, and the respiratory tract. It should be handled in a well-ventilated area with appropriate personal protective equipment, including gloves and eye protection, and waste must be disposed of as hazardous chemical material. Nitroaromatic compounds require careful handling to minimize hazards such as shock sensitivity and environmental impact.