Background and overview[1]
The 2,4-dinitrophenylhydrazine (DNPH) colorimetric method is a classic method for determining the carbonyl content of proteins. The oxidized protein carbonyl content increases, and the carbonyl group can react with 2,4-dinitrophenylhydrazine to form 2,4-dinitrophenylhydrazone, 2,4-dinitrophenylhydrazone is a reddish-brown precipitate. After dissolving the precipitate with guanidine hydrochloride, the absorbance value at 370nm can be read on a spectrophotometer to determine the protein. The carbonyl content. 2,5-Dimethylbenzaldehyde-2,4-DNPH is a chemical substance with the molecular formula C15H14N4O4, which can be used as a pharmaceutical synthesis intermediate. If 2,5-dimethylbenzaldehyde-2,4-DNPH is inhaled, please move the patient to fresh air; if there is skin contact, take off contaminated clothing and wash the skin thoroughly with soap and water. If there is any discomfort If you feel sick, seek medical attention; if eye contact occurs, separate eyelids, rinse with running water or saline, and seek medical attention immediately; if ingested, rinse mouth immediately, do not induce vomiting, and seek medical attention immediately.
Highly selective reaction of DNPH with carbonyl compounds such as 2,5-dimethylbenzaldehyde-2,4-DNPH allows detection of derivatized carbonyl compounds. Second, the characteristic loss of the hydroxyl radical used to trigger MS3 cleavage is only observed in the positive ionization of aminonitroaromatics, allowing selective detection and cleavage of DNPH-derived carbonyl groups. Finally, the presence of specific fragment ions minimizes possible false positive identifications due to the presence of derivatizing agents such as 2,5-dimethylbenzaldehyde-2,4-DNPH. Studies have used DNPH with carbonyl compounds (e.g., 2,5-dimethylbenzaldehyde-2,4-DNPH) to characterize toxic and genotoxic carbonyl compounds produced by specific exposures and to monitor the endogenous formation of carbonyl compounds. Examples include carbonyl compounds derived from inflammatory processes associated with lipid peroxidation and oxidative stress.
Main reference materials
[1] A High Resolution/Accurate Mass (HRAM) Data-Dependent MS3 Neutral Loss Screening, Classification, and Relative Quantitation Methodology for Carbonyl Compounds in Saliva