Volatile Polonium and Tellurium Species in the Marine Environment

在这个项目中，特拉华大学的研究人员将研究海洋环境中挥发性钚(Po)和碲(Te)物种的形成。通过与天然放射性核素210Po及其稳定的XVI族同系物Te的比较，这两种元素可以提供海-气类金属逃逸的度量。钚和碲的基本化学性质表明，烷基化将通过常见的反应发生，而且有强有力的现场证据表明，海洋环境中这两种元素的挥发性物种的产生。然而，在海洋系统中还没有直接观察到挥发性物种。研究人员假设，稳定的烷基化合物钋和碲有助于它们跨越海洋大气边界的挥发性通量。这一假设将通过分析开发、实验室反应、微生物甲基化分析和现场采样研究进行验证，从而首次在海洋环境中鉴定出直接挥发性物种。将开发分析方法，包括用于物种分离和鉴定的GC-ICPMS技术。实验室研究将测试非生物甲基化反应的烷基化产物，以及为生物产生挥发性碲和钚物种而培养的微生物培养物。最后，将对自然沉积物批量孵化的顶空分析和预期甲基化活性的海洋区域顺风向顶空分析进行抽样，以检测自然产生的挥发性产物钋和碲。更广泛的影响：该项目将处理全球重要的生物地球化学过程，包括潜在的污染物转移和海洋生物胁迫。研究生和研究生将获得开发下一代分析技术来解决这些过程的经验。本科生将参与NSF赞助的研究，通过接触NSF-REU(面向本科生的研究经验)计划下的建议研究，获得教育和专业经验。

ABSTRACTOCE-0425199In this project, researchers at the University of Delaware will study the formation of volatile polonium (Po) and tellurium (Te) species in marine environments. These two elements may provide a metric of air-sea metalloid evasion using the natural radionuclide 210Po by comparison to its stable Group XVI congener Te. The basic chemical properties of polonium and tellurium suggest that alkylation will occur via common reactions, and strong field evidence exists for the production of volatile species of both elements in marine environments. However, volatile species have not yet been directly observed in marine systems. The researchers hypothesize that stable alkyl species of polonium and tellurium contribute to their volatile flux across the marine atmospheric boundary. This hypothesis will be tested through analytical development, laboratory reactions, microbial methylation assays, and field sampling studies leading to the first direct volatile species identification in the marine environment. Analytical methods will be developed including GC-ICPMS technologies for species separation and identification. Laboratory studies will test for alkylated products of abiotic methylation reactions, and microbial cultures grown for biotic generation of volatile tellurium and polonium species. Finally, both head space analysis in batch incubation of natural sediments and downwind of marine areas with expected methylation activity will be sampled for naturally occurring volatile products of polonium and tellurium. Broader Impacts: This project will deal with globally significant biogeochemical processes that include potential pollutant transfer and marine biotic stress. Graduate and post-graduate students will gain experience developing next generation analytical techniques to address such processes. Undergraduate students will participate in the NSF-sponsored research resulting in educational and professional experiences by exposure to the proposed research under the NSF-REU (Research Experience for Undergraduates) program.