Assay of Brain Endogenous Formaldehyde With 2, 4-Dinitrophenylhydrazine Through UV-HPLC*: Assay of Brain Endogenous Formaldehyde With 2, 4-Dinitrophenylhydrazine Through UV-HPLC*

Chronic impairments of brain caused by accumulation of endogenous formaldehyde as ageing is thought as one of the risk factors for sporadic age-related dementia.Thus,it is necessary to determine the endogenous concentration of formaldehyde in brain.Using 2,4-dinitrophenylhydrazine(2,4-DNPH) in the assay, the concentrations of formaldehyde in parietal lobe,frontal lobe,temporal lobe,occipital lobe,hippocampus, cerebellum and brainstem of porcine brain(n=5) were measured through UV-HPLC.Homogenizing brain tissues with 10% trichloroacetic acid(pH =1.0) not only avoided the disturbance from contaminated protein and other compounds,but also eliminated the step extraction of FA-DNPH derivative(2,4-dinitrophenylhydrazone) and improve the methodological sensitivity(P 0.05).The porcine brain formaldehyde was 75.5～83.4 μmol/kg fresh brain tissues measured by this improved method.Recoveries of spiked formaldehyde at low and high level were 95.96%～102.04% with relative standard deviations less than 10%.This suggests that the modified 2,4-DNPH method is effective enough to measure the endogenous formaldehyde in brain tissues.