Zoic acid (DTNB) which is then read at 412 nm. Determination of lipid peroxidation product (malondialdehyde, MDA) in brain tissue homogenate This method is based on the determination of malondialdehyde (MDA), an end product of lipid peroxidation, which reacts with thiobarbituric acid to yield a pink coloured trimethine complex exhibiting a maximum absorbance at 530-532 nm [28]. HPLC determination