Thomas M J, Robison T W, Samuel M, Forman H J
Department of Biochemistry, Wake Forest University Medical Center, Winston-Salem, NC 27157-1016, USA.
Free Radic Biol Med. 1995 Mar;18(3):553-7. doi: 10.1016/0891-5849(94)e0121-x.
The detection of aldehydes has become an important measure of lipid oxidation in biological milieu. Aldehyde 2,4-dinitrophenylhydrazones are easily prepared and readily purified by HPLC and/or TLC and have proven useful for the detection of aldehydes. The lower limit of detection for dinitrophenylhydrazones was significantly reduced by using gas chromatography-mass spectrometric (GC-MS) techniques. Individual dinitrophenylhydrazones were readily separated by GC and detected by both positive and negative ion MS. The two major ions in negative ion spectra were the 182 m/z fragment ion and the molecular ion. Positive ion spectra showed strong ions corresponding to the protonated molecular ion and a protonated iminium ion. The greatest sensitivity was obtained with negative ion detection (10 pg per injection). However, more structural information was obtained from analysis of the positive ion spectra. Dinitrophenylhydrazones of hydroxyaldehydes, like 4-hydroxynonenal, were analyzed after converting the dinitrophenylhydrazones into trimethylsiloxylethers. GC-MS with negative ion detection was used to identify and quantitate the release of 4-hydroxynonenal by alveolar macrophages exposed to nitrogen dioxide.
醛的检测已成为生物环境中脂质氧化的一项重要指标。醛的2,4-二硝基苯腙易于制备，且通过高效液相色谱法（HPLC）和/或薄层色谱法（TLC）很容易纯化，已被证明可用于醛的检测。通过使用气相色谱 - 质谱联用（GC-MS）技术，二硝基苯腙的检测下限显著降低。单个二硝基苯腙很容易通过气相色谱分离，并通过正离子和负离子质谱进行检测。负离子光谱中的两个主要离子是182 m/z碎片离子和分子离子。正离子光谱显示出与质子化分子离子和质子化亚胺离子相对应的强离子。负离子检测获得了最高灵敏度（每次进样10 pg）。然而，从正离子光谱分析中获得了更多的结构信息。在将二硝基苯腙转化为三甲基硅氧基醚后，对羟基醛（如4-羟基壬烯醛）的二硝基苯腙进行了分析。采用负离子检测的GC-MS用于鉴定和定量暴露于二氧化氮的肺泡巨噬细胞释放的4-羟基壬烯醛。
