Kinetic behaviour of the malonaldehyde-thiobarbituric acid reaction. kinetic-fluorimetric determination of malonaldehyde in human serum

For the first time a fluorimetric-kinetic method for the determination of malonaldehyde (MLD) is proposed. The fluorescence emission of the thiobarbituric acid (TBA)-MLD reaction product has been monitored at 553 nm (excitation wavelength 515 nm), and the instrumental and experimental variables have been studied. A selective and fast kinetic-fluorimetric determination of malonaldehyde is proposed. The sensitivity of the method is very high, the detection limit is 0.30 ng ml−1, the application range is between 1.1 and 50 ng ml−1, and the determination time per sample is 500 s. The kinetic-fluorimetric method has been applied in the determination of two types of pathological human serum: rheumatic and hyperlipemic serum. In both cases, perchloric acid is used to precipitate the proteins.