This document discusses several methods for assessing malondialdehyde (MDA) levels in the body, including gas chromatography of expired breath compounds, analysis of age-related pigments, and spectrophotometry of conjugated dienes. The most widely used method is colorimetry or fluorimetry of the thiobarbituric acid (TBA) reaction, which produces a stable pink to red product that absorbs maximally at 532 nm. This TBA reaction method is faster and less expensive than high-performance liquid chromatography (HPLC) analysis, though both can be used to measure MDA and other reaction products.

1. METHODS OF ASSESSING MDA
LEVELS IN BODY

2. METHODS
 Gas chromatography of ethane, ethene, and
pentane in expired breath
 Analysis of age-related
pigments(e.g., lipofuscin, ceroid) based on
characteristic fluorescence and emission spectra
 Spectrophotometry of conjugated dienes at 233 nm
 Colorimetry and fluorimetry of MDA and other
chromogens based on the thiobarbituric acid (TBA)
reaction
 The measurement of various products by high
performance liquid chromatography (HPLC)

3.  The ThioBarbituric Acid (TBA) reaction, quantified by
colorimetry or fluorimetry, is the method most widely
used for studying lipid peroxidation in both laboratory
animals and in humans with disorders
 The reaction products were also analyzed for MDA by
high-performance liquid chromatography (HPLC)

4. MDA + 2 TBA Stable Pink to Red
colour that
absorbs maximally at
532 nm

6.  Sensitivity:
Fourfold greater than that of Yagi’s
 Specificity:
Same specificity problems as Yagi’s
 Practicability:
More practicable and better adapted
to measurements of large series of samples
 Faster than the HPLC technique and less
expensive.