St-Germain F, Vachon B, Montgomery J, Des Rosiers C
Département de Nutrition, Université de Montréal, Québec, Canada.
Free Radic Biol Med. 1997;23(1):166-72. doi: 10.1016/s0891-5849(96)00628-4.
A new interface coupled to a mass spectrometer was developed for the direct analysis of volatile organic compounds from small volumes of aqueous samples, including blood or tissue homogenates (St-Germain et al. 1995, Anal. Chem. 67:4536-4541). The greatest advantages of our system are minimal sample treatment, an instantaneous response time coupled with detection limits in the range of < 1 ppb for most compounds. For the analysis of low-molecular weight aldehydes, such as formaldehyde, acetaldehyde, propanal, and hexanal, lower detection limits were obtained when samples were converted to methoxime derivatives prior to injection. The detection limit for hexanal in water or Krebs-Ringer solution was 0.01 microM (10 pmol injected). The reproducibility of replicate injections was 4.4%. The usefulness of our system was illustrated by measuring aldehyde accumulation in peroxidized solutions of polyunsaturated fatty acids and rat tissue homogenates. Data confirmed that peroxidation of omega-3 fatty acids produces propanal, whereas omega-6 fatty acids form hexanal. Peroxidation of heart and brain homogenates formed predominantly propanal. However, the recovery of hexanal after sample treatment with methoxylamine depended on the derivatization time and temperature, suggesting that this aldehyde may form Schiff base linkages. These results show that spray extraction coupled to mass spectrometry provides a quick (< 1 min), clean and reproducible way to detect aldehydes produced from lipid peroxidation in aqueous samples.
开发了一种与质谱仪相连的新接口，用于直接分析少量水性样品中的挥发性有机化合物，这些样品包括血液或组织匀浆（St - Germain等人，1995年，《分析化学》67:4536 - 4541）。我们系统的最大优点是样品处理最少，响应时间即时，且大多数化合物的检测限在< 1 ppb范围内。对于低分子量醛类的分析，如甲醛、乙醛、丙醛和己醛，在进样前将样品转化为甲氧肟衍生物时可获得更低的检测限。水中或 Krebs - Ringer 溶液中己醛的检测限为0.01 microM（进样10 pmol）。重复进样的重现性为4.4%。通过测量多不饱和脂肪酸过氧化溶液和大鼠组织匀浆中的醛积累情况，说明了我们系统的实用性。数据证实，ω - 3脂肪酸过氧化产生丙醛，而ω - 6脂肪酸形成己醛。心脏和脑组织匀浆的过氧化主要形成丙醛。然而，用甲氧基胺处理样品后己醛的回收率取决于衍生化时间和温度，这表明该醛可能形成席夫碱键。这些结果表明，喷雾萃取与质谱联用为检测水性样品中脂质过氧化产生的醛提供了一种快速（< 1分钟）、清洁且可重现的方法。
