Formaldehyde 2,4-dinitrophenylhydrazone (DNPH derivative) is primarily used as an analytical standard and reference compound in chromatographic and spectrophotometric methods for the quantification of carbonyl compounds, especially formaldehyde. It serves as a calibration standard in techniques like HPLC and GC-MS for environmental monitoring (e.g., air and water quality), food safety testing, and pharmaceutical analysis. This compound is valued for its stability and characteristic UV absorbance, enabling accurate detection and measurement of trace carbonyl levels. It is also utilized in research to validate methods for studying carbonyl group reactions.