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Updated: Sep 23, 2025
Evaluation of Oxidative Stress in Biological Samples Using the Thiobarbituric Acid Reactive Substances Assay
Published on: May 12, 2020
An Improved GC-MS Method for Malondialdehyde (MDA) Detection: Avoiding the Effects of Nitrite in Foods
Wenjie Wang1,2,3,4, Zhiwen Zhang1,2,3,4, Xiaoying Liu1,2,3,4
1College of Food Science and Technology, Zhejiang University of Technology, Hangzhou 310014, China.
Abstract:
Malondialdehyde (MDA) is one of the representative end products under lipid peroxidation, indicating the degree of lipid oxidation in foods. However, compounds in pickled products, especially the nitrite in salted lean pork can react with MDA under the acidic condition, leads to the loss of MDA and an underestimation on lipid oxidation through the conventional assay. In this study, the quantification for MDA in the sample containing sodium nitrite were found lacking accuracy by the thiobarbituric acid (TBA) assay and chromatography assay based on alkaline hydrolysis as the reaction between them were difficult to be completely inhibited. Among other trials, the improvement GC-MS analysis utilizing deuterium substituted MDA (MDA-d2) as an internal standard and applying perfluorophenylhydrazine (PFPH) as a derivative reagent can reduce the deviations from the presence of nitrite in the salted lean pork meat and the recovery is between 93.9% and 98.4% and coefficient of variation for the intermediate precision is between 1.1 and 3.5% using the method. The advanced gas chromatograph mass spectrometer (GC-MS) assay also has a very low detection limit (0.25 ng/mL) with both hydrolysis types.
Insights
This study introduces an improved GC-MS method for accurately measuring malondialdehyde (MDA), a marker of lipid oxidation, in foods like salted pork. The new technique overcomes issues caused by nitrites, ensuring reliable lipid oxidation assessment.
Area of Science:
- Food Chemistry
- Analytical Chemistry
- Biochemistry
Background:
- Lipid peroxidation, indicated by malondialdehyde (MDA), is crucial for assessing food oxidation.
- Conventional MDA assays are inaccurate in nitrite-containing foods due to reactions that underestimate oxidation.
- Pickled products and salted meats pose challenges for accurate lipid oxidation measurement.
Purpose of the Study:
- To develop a precise method for quantifying MDA in the presence of nitrite.
- To overcome the underestimation of lipid oxidation in salted lean pork.
- To validate an improved analytical technique for food quality assessment.
Main Methods:
- Comparison of thiobarbituric acid (TBA) assay and chromatography with alkaline hydrolysis against a new method.
- Development of an improved Gas Chromatography-Mass Spectrometry (GC-MS) assay.
- Utilizing deuterium-substituted MDA (MDA-d2) as an internal standard and perfluorophenylhydrazine (PFPH) as a derivatizing agent.
Main Results:
- Conventional assays showed inaccuracies due to nitrite interference.
- The improved GC-MS method with MDA-d2 and PFPH demonstrated high recovery rates (93.9–98.4%).
- The method exhibited excellent intermediate precision (coefficient of variation 1.1–3.5%) and a low detection limit (0.25 ng/mL).
Conclusions:
- The enhanced GC-MS assay accurately quantifies MDA in salted lean pork, mitigating nitrite interference.
- This method provides a reliable tool for assessing lipid oxidation in challenging food matrices.
- The improved analytical approach ensures more accurate food quality and safety evaluations.
