Kohlenoxydvergiftung in geschlossenen Garagen

The Science of Nature -     

The kinetics of reductive dehalogenation of a set of halogenated aliphatic hydrocarbons in anaerobic sediment slurries

Disappearance rate constants are reported for the reductive transformation of 17 halogenated aliphatic hydrocarbons in anaerobic sediment-water samples. Statistical experimental design in combination with multivariate chemical characterization of their chemical properties was used to select the compounds. Degradation followed pseudo first-order kinetics through at least two half-lives for 15 of the 17 compounds. Of all the compounds investigated, 1,2,3-trichloropropane and dichloromethane were unique in that they were dehalogenated according to zero-order kinetics. Reductive dehalogenation was the sole transformation reaction taking place.     

高效液相色谱/紫外/大气压化学电离-质谱联用用于聚合物中抗氧化添加剂的分析(二)

3 未知物的鉴定。保留时间可以使有经验的色谱工作者推测在相同的条件下,未知物的峰与一组已知物在结构上有什么差异,但是,鉴定需要更多的信息,而不是只靠所提供的色谱出峰模式．根据UV／VIS数据,我们通常可以推断分子的类别,特别是在我们讨论的化合物中都具有酚基团的化学结构更是如此．UV／VIS谱图可以用于推测,但若不预先掌握重要的相关知识,这种推测还不足以确证鉴定．另一方面,质谱数据具备推测结构细节必须的光谱分辨率,故可实现实际的化学鉴定．以下实例描述了几种情况,其中两个检测器对结构鉴定都是有帮助的．