Collaborative Research: Chemical Changes Accompanying Petroleum Weathering in the Coastal Ocean

沿海海洋中石油碳氢化合物的风化是海洋化学家和环境化学家三十多年来一直感兴趣的现象。虽然已经有无数关于这一主题的研究，但由于传统分析技术提供的分析窗口狭窄，导致基本问题没有得到解答，因此进展停滞不前。在这个项目中，加州大学圣巴巴拉分校和伍兹霍尔海洋研究所的研究人员将以一种新的方式来研究这个问题，通过协同应用两种先进的方法：全面的二维气相色谱法和傅立叶变换离子回旋共振质谱法，为数百到数千种石油碳氢化合物的风化提供前所未有的详细信息。具体来说，这项研究将确定和分配与石油风化有关的光解、蒸发、溶解和生物降解的作用，在加州圣巴巴拉的自然石油渗漏中，每年有超过500万升的石油渗入海洋。这项工作直接解决了美国国家研究委员会2003年报告《海洋石油III》的建议，并将受到两个主要假设的推动：(1)长期浮油中的碳氢化合物质量损失主要是蒸发、生物降解、溶解和光氧化；(2)石油中的高分子量和极性化合物主要在浅层沉积物中通过微生物作用转化，产生高分子量溶解有机分子和残余焦油。这些假设将通过收集和分析圣巴巴拉渗漏的石油样本来解决。每个样品中分子分布的变化将作为环境暴露的函数进行评估，以提供假设的检验。新的数据分析工具也将被开发和验证。更广泛的影响：本研究的结果将广泛有助于理解地球系统中的石油风化和碳循环，并将通过流行渠道广泛传播。从这项研究中获得的知识也将直接转化为联邦机构，包括国家海洋和大气管理局的评估和恢复司，这些信息对石油泄漏后的短期和长期决策至关重要。本研究对教育的直接影响包括本科生和研究生的培养和教育。

The weathering of petroleum hydrocarbons in the coastal ocean is a phenomenon that marine chemists and environmental chemists have been interested in for more than three decades. While there have been countless studies on this topic, advances have stalled due to the narrow analytical windows provided by traditional analytical techniques, leaving fundamental questions unanswered. In this project, researchers at the University of California at Santa Barbara and the Woods Hole Oceanographic Institution will look at this problem in a new way through a concerted application of two advanced approaches: comprehensive, two-dimensional gas chromatography and Fourier transform ion cyclotron resonance mass spectrometry, to provide an unprecedented level of detail on the weathering of hundreds to thousands of petroleum hydrocarbons. Specifically, this research will identify and apportion the role of photolysis, evaporation, dissolution, and biodegradation associated with oil weathering at the natural oil seeps off Santa Barbara, CA, where more than 5 million liters of oil seep annually into the ocean. This effort directly addresses recommendations by the US National Research Council's 2003 report Oil in the Sea III, and will be driven by two overarching hypotheses: (1) Hydrocarbon mass loss in chronic oil slicks is dominated by evaporation biodegradation dissolution photo-oxidation; and (2) High-molecular-weight and polar compounds in petroleum are transformed primarily in shallow sediments by microbiological processes, yielding high molecular weight dissolved organic molecules and a residual tar. These hypotheses will be addressed by collecting and analyzing oil samples from the Santa Barbara seeps. Changes in the distribution of molecules within each sample will be assessed as a function of environmental exposure to provide tests of the hypotheses. New data analysis tools will also be developed and validated. Broader Impacts: Results from this research will contribute broadly to an understanding of petroleum weathering and carbon cycling in the Earth system, and will be broadly disseminated through popular outlets. Knowledge gained from this research will also be translated directly to federal agencies including the National Oceanic and Atmospheric Administration's Assessment and Restoration Division where such information is critical for short and long-term decision making following oil spills. Direct educational impacts of this research include the training and education of undergraduate and graduate students.