Determination of malonaldehyde in oxidized biological materials by high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) method was used to determine the level of malonaldehyde (MA) in materials containing unsaturated fatty acids and rat liver microsomes peroxidized in vitro. The detection limit was 8.3 pmol for fatty acid samples and 25 pmol for microsomal samples. The method was specific to MA and the relative standard deviation was 4.34-5.14%. The recovery of MA was about 100%. In general, the MA values in oxidized materials obtained by the proposed HPLC method were lower than those obtained by the thiobarbituric acid method, although similar results were obtained with both methods for microsomal samples oxidized by NADPH. The effect of temperature on the HPLC results was investigated and it was found that the MA values obtained by derivatization at 25 degrees C, followed by separation using HPLC, reflected the situation of the peroxidation more accurately.