Acetaldehyde 2,4-Dinitrophenylhydrazone is the 2,4-dinitrophenylhydrazone derivative of acetaldehyde, formed by the reaction of acetaldehyde with 2,4-dinitrophenylhydrazine (DNPH). It serves as a reference standard in analytical chemistry for the identification and quantification of carbonyl compounds, particularly acetaldehyde. This compound is commonly used in chromatographic techniques such as HPLC and GC, as well as in spectrophotometric methods, to detect and measure aldehydes in environmental, biological, food, and industrial samples. Its characteristic yellow to orange color, stability, and distinct spectral properties make it valuable for calibration, validation, and qualitative/quantitative analysis in research and laboratory settings.