Determination of malondialdehyde by capillary electrophoresis, application to human plasma and relation of its levels with prematurity

Malondialdehyde (MDA) is considered as the most important marker for monitoring lipid peroxidation, which is strongly associated with the development of serious diseases in adults and premature neonates. In this paper we report a method for determination of free MDA in human plasma using capillary zone electrophoresis. MDA was separated and determined as conjugate with tetrabutylammonium hydrogen sulphate (TBAS). Analysis was performed using 20 mM borare, pH = 9.3, as operating buffer and detection of the MDA-TBAS adduct at 267 nm. The method has a linear range up to 80 microM with a detection limit of 0.2 microM. The method was applied to the analysis of MDA in plasma of healthy adults, normal-gestation infants and of preterm neonates. Plasma proteins were successfully removed following centrifugation through a centricon-3 membrane. Results showed that the method can be easily and accurate applied for the determination of MDA in human plasma and that the level of MDA in pretern neonates is significantly higher (p <or= 0.001) as compared to the two Other cases. This suggests that MDA analysis may be useful to monitor the development and process of diseases related to lipid peroxidation, oxidative stress and prematurity.