A Modified Spectrophotometric Method for the Determination of Hydrazine

Abstract
The method is based on the reaction of p-dimethylaminobenzaldehyde with hydrazine and the formation of p-dimethylaminobenzaldazine, which, in the presence of strong acids, is rearranged into a p-quinoic chromophore structure. It was found that sufficient time must be allowed for the completion of aldazine formation and the most intensive color, proportional to the concentration of hydrazine, is developed in the presence of concentrated glacial acetic acid. The method is extremely sensitive and applicable to the determination of hydrazine in biological material.