1989 Volume 38 Issue 11 Pages 652-654
Malonaldehyde(MA) reacted with phenylhydrazines to form pyrazole derivatives. The behavior of the three hydrazines, 2, 4-dinitrophenyl-(DNPH), p-nitrophenyl-(NPH) and phenyl-(PhH), in the reaction with MA was compared by HPLC. A Shimadzu LC-5A HPLC equipped with a UV detector (315 nm for DNPH-MA and NPH-MA, 265 nm for PhH-MA) was used for the analysis. A metal column (25 cm×4.6 mm i.d.) was packed with 5-μm Develosil ODS (Nomura Chemical Co., Ltd., Japan). Elution was carried out with CH3CN-0.01 M HCl (40: 60, v/v) at a flow rate of 1.5 ml/min. The reaction of MA with DNPH required a strongly acidic condition, while NPH and PhH reacted well with MA in a weakly acidic medium. The highest peak of the three derivatives was observed from reaction with NPH. The results above showed NPH to be quite useful for estimating a trace amount of free MA in a mild condition.
