Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria.
Free Radic Res. 2013 Aug;47(8):651-6. doi: 10.3109/10715762.2013.812205. Epub 2013 Jul 2.
Malondialdehyde (MDA) is considered to be a biomarker for enzymatic degradation and lipid peroxidation of polyunsaturated fatty acids. Usually, MDA determination from different biological materials is performed by reaction with thiobarbituric acid (TBA) followed by high-performance liquid chromatography (HPLC) analysis and fluorometric detection. As this method lacks specificity and sensitivity, we developed a gas chromatography-mass spectrometry (GC-MS) method based on derivatization of MDA with 2,4-dinitrophenylhydrazine. Representative ions in negative ion chemical ionization (NICI) mode were recorded at m/z 204 for MDA and at m/z 206 for the deuterated analogon (MDA-d₂) as internal standard. This stable and precise GC-MS method showed good linearity (r² = 0.999) and higher specificity and sensitivity than the HPLC method and was validated for both total MDA (t-MDA) and free MDA (f-MDA). Within-day precisions were 1.8-5.4%, between-day precisions were 4.8-9.2%; and accuracies were between 99% and 101% for the whole calibration range (0.156-5.0 μmol/L for t-MDA and 0.039-0.625 μmol/L for f-MDA). Although comparison of t-MDA levels from GC-MS and HPLC results using Passing-Bablok regression analysis as well as Bland-Altman plot showed a correlation of the data, a tendency to increased results for the HPLC values was detectable, due to possible formation of unspecific products of the TBA reaction.
丙二醛（MDA）被认为是多不饱和脂肪酸酶解和脂质过氧化的生物标志物。通常，通过与硫代巴比妥酸（TBA）反应，然后进行高效液相色谱（HPLC）分析和荧光检测，从不同的生物材料中测定 MDA。由于该方法缺乏特异性和灵敏度，我们开发了一种基于 MDA 与 2,4-二硝基苯肼衍生化的气相色谱-质谱（GC-MS）方法。在负离子化学电离（NICI）模式下，记录到 MDA 的代表性离子为 m/z 204，氘代类似物（MDA-d₂）为内标，m/z 206。该稳定且精确的 GC-MS 方法具有良好的线性（r²=0.999），比 HPLC 方法具有更高的特异性和灵敏度，并且对总 MDA（t-MDA）和游离 MDA（f-MDA）均进行了验证。日内精密度为 1.8-5.4%，日间精密度为 4.8-9.2%；在整个校准范围内（t-MDA 为 0.156-5.0 μmol/L，f-MDA 为 0.039-0.625 μmol/L），准确度在 99%-101%之间。虽然使用 Passing-Bablok 回归分析和 Bland-Altman 图比较 GC-MS 和 HPLC 结果的 t-MDA 水平显示数据相关，但由于 TBA 反应可能形成非特异性产物，可检测到 HPLC 值的结果增加趋势。
