Jezequel-Cuer M, Le Moël G, Covi G, Lepage S, Peynet J, Gousson-Evstigneeff T, Laureaux C, Troupel S
Laboratoire de biochimie A, hôpital Bichat, Paris, France.
Ann Biol Clin (Paris). 1994;52(4):271-6.
Incomplete and controversial data exist concerning vitamin E or alpha-tocopherol stability in biological samples. Recent clinical interest in the protective function of alpha-tocopherol provided another reason for the setting-up of a multicenter study by the Sociéte Française de Biologie Clinique. Our purpose was to examine the effects on alpha-tocopherol stability, firstly, of collection and transportation of blood samples, and, secondly, of the temperature (-20 degrees C and -80 degrees C) and period of storage of serum or plasma. alpha-tocopherol was determined in serum or plasma by isocratic liquid chromatography with UV detection at 292 nm. Our results established that alpha-tocopherol was extremely stable in blood, serum or plasma over 8 hours without special handling conditions (light, temperature). Pools of serum or plasma were stable for at least 3 months at -20 degrees C and -80 degrees C. They are suitable for use in the quality control of alpha-tocopherol. On the other hand, in some samples, we observed great variability in the rate of alpha-tocopherol degradation. However, there was lesser degradation when these plasma samples were stored at -80 degrees C instead of -20 degrees C. We therefore do not advise storing serum or plasma for more than 1 month at -20 degrees C for more than 3 months at -80 degrees C. This latter temperature is recommended in epidemiological studies.
关于生物样本中维生素E或α-生育酚的稳定性，存在不完整且有争议的数据。近期临床对α-生育酚保护功能的关注，为法国临床生物学协会开展多中心研究提供了另一个理由。我们的目的是，首先研究血样采集和运输对α-生育酚稳定性的影响，其次研究血清或血浆在-20℃和-80℃温度下的储存温度及储存时间对其稳定性的影响。采用等度液相色谱法，于292nm波长处进行紫外检测，测定血清或血浆中的α-生育酚。我们的结果表明，在无特殊处理条件（光照、温度）下，α-生育酚在血液、血清或血浆中8小时内极其稳定。血清或血浆样本在-20℃和-80℃下至少3个月稳定。它们适用于α-生育酚的质量控制。另一方面，在一些样本中，我们观察到α-生育酚降解速率存在很大差异。然而，当这些血浆样本储存在-80℃而非-20℃时，降解较少。因此，我们不建议在-20℃下将血清或血浆储存超过1个月，在-80℃下储存超过3个月。在流行病学研究中推荐使用后一种温度。
