Investigating Novel Halogenated Organic Compounds in the Ocean

在动物组织中发现的几种不同的卤代有机化合物（HOCs）被认为是工业或天然来源，但没有确凿的证据支持这两种来源。作为帮助确定海洋中这些化合物来源的一种手段，伍兹霍尔海洋研究所的研究人员将在该项目中得到支助，继续开发一种采用分子水平放射性碳（14 C）和稳定氮同位素分析的多同位素示踪方法。放射性碳是确定这些化合物来源的理想示踪剂，因为所有最近的天然产物都应该预先标记至少一些14 C。相比之下，几乎完全由石化原料合成的工业化合物不含可测量的14 C。先前支持的初步研究表明，这是一种可行的方法。许多HOC在每个分子中含有两个原子。如果14 C数据表明是天然来源，则将使用分子水平的稳定氮分析来确定生物合成的营养水平。现在可以获得样本，并且分析方法也已得到很好的开发。许多卤代联吡咯将是目标化合物。后者将从被发现搁浅在北美太平洋和大西洋沿岸沿着的海洋哺乳动物中分离出来。就更广泛的影响而言，确定这些HOC的来源显然具有社会经济重要性。例如，如果其中一些化合物确实来自人类活动，则需要认真考虑其来源和生产方式，以及是否能够或应该控制其排放。PI积极为博士后，研究生和本科暑期学生提供咨询。拟议的研究计划将形成两个博士学位的基础。学位论文这项研究的结果也将纳入麻省理工学院-世界卫生组织海洋学联合方案的课程。

Several different halogenated organic compounds (HOCs) found in animal tissues have been suggested to have either industrial or natural sources, yet there is no conclusive evidence supporting either source. As a means to help identify the sources of these compounds in the ocean, researchers at the Woods Hole Oceanographic Institution will be supported in this project to continue development of a multi-isotopic tracer approach employing molecular-level radiocarbon (14C) and stable nitrogen isotope analysis. Radiocarbon is an ideal tracer for establishing the origin of these compounds since all recent natural products should be pre-labeled with at least some 14C. In contrast, industrial compounds, which are almost exclusively synthesized from petrochemical feedstock, contain no measurable 14C. Initial studies from previous support have shown that this is a viable approach. Many of these HOCs contain two atoms in each molecule. If the 14C data indicates a natural source, molecular-level stable nitrogen analyses will used to determine the trophic level of biosynthesis. Access to samples is now available and analytical methods have been well developed. Numerous halogenated bipyrroles will be the targeted compounds. The latter will be isolated from marine mammals found stranded along the Pacific and Atlantic coasts of North America. In terms of broader impacts, it is clear that establishing the origin of these HOCs is of socioeconomic importance. For example, if some of these compounds indeed turn out to derive from anthropogenic activity, careful consideration would need to be given to their source and mode of production and to whether their emissions can or should be controlled. The PI is active in advising postdoctoral, graduate and undergraduate summer students. The proposed research program will form the foundation for two Ph.D. dissertations. Findings from this study will also be incorporated into the curriculum of the MIT-WHOI Joint Program in Oceanography.