[Modification of the determination of lipid peroxidation products in a reaction with thiobarbituric acid].

The aim of the study was to choose the optimal conditions for spectrophotometry of the blood serum lipid peroxidation (LPO) products by the thiobarbituric acid (TBA) test. LPO products have been measured in trichloroacetic acid filtrate and in lipoprotein sediment by spectrophotometry and fluorometry. The optimal conditions for spectrophotometry of TBA-active LPO products are as follows: the proteins are sedimented with 20% solution of phosphotungstic acid, stabilizing the pH values in 1.3-1.5 range; the incubation temperature is 99-100 degrees C; the optic density of the aqueous extract is measured spectrophotometrically at wavelengths 535 and 580 nm. The suggested method permits spectrophotometry of LPO products without additional extraction with butanol, and its results are compatible with those of fluorometry. The coefficient of convergence variations is 3.42%, the repeatability factor 3.31%.