1991 Volume 40 Issue 3 Pages 143-147
The determination of malondialdehyde (MDA) which is an end product of the hydrolysis of 1, 1, 3, 3-tetramethoxypropane (TMP) was investigated spectrophotometrically. TMP in aqueous solution, adjusted pH to 1, was completely hydrolyzed, after 5h at 25°C. The rate constant of hydrolysis was 2.78×10-4s-1. The determination of MDA is carried out as follows: take 1ml of a sample solution, which contain less than 6.5×10-6M of MDA, add 12ml of a solution, which has 6.9×10-2M thiobarbituric acid dissolved in 5×10-2M sodium hydroxide; after adjusting pH to 1 with hydrochloric acid, dilute this solution with water to a 15ml; put the sample in boiling water for 15min and after cooling for 2h at room temperature, read the absorbance value. The calibration curve was prepared from MDA obtained by the hydrolysis of TMP. The linear relationship between the concentration of MDA and the absorbance was in the range of 0.5×10-6M to 6.5×10-6M. The molar extinction coefficient was 1.4×105l mol-1cm-1 at the wavelength of 532nm. This procedure can be applied to the determination of hydroxy radical.
