Collaborative Research: A GEOTRACES Intercalibration of Collection, Handling and Analysis Methods for Mercury Species in Seawater

汞在公海中的浓度很低（fM-pM），并受到复杂的地球化学循环的影响。为了了解这种循环，有必要确定海洋中发现的主要汞种类（汞离子、元素汞、单甲基汞和二甲基汞;分别为Hg（II）、Hgº、MMHg和DMHg），但这会带来巨大的分析挑战。这些形式可以是挥发性的和光敏的，它们的低浓度使得即使少量的污染也是毁灭性的。但是，研究海洋中的汞也有重要的益处，包括加深对有毒金属的来源和生物累积动力学的了解，海洋中有机金属化合物（包括锗、硒、磷、砷）的形成，评估一种生物活动元素的影响，以及可能开发一种古生产力代用指标。在该奖项的资助下，伍兹霍尔海洋学研究所、康涅狄格大学、巴特尔纪念研究所和赖特州立大学的研究人员将参加即将举行的GEOTRACES相互校准巡航，以启动一项全面的、多调查员/实验室比较，确定海水中的汞（Hg）种类。这种相互校准是全面开展GEOTRACES巡航活动之前至关重要的第一步，以便在该项目范围内研究汞的化学海洋学的各种调查人员可以比较他们的结果，该项目旨在分散进行，其范围之广，任何一个实验室都不可能完成全部工作。该项目将包括海岸和实地（参加两次航行）两个部分。在实验室中，该小组将测试由聚四氟乙烯以外的塑料制成的瓶子的清洁度，以及长期储存在巡航期间收集的样品用于总量和物种测量的前景。该奖项将仅支持该项目的实地部分，其余工作将由其他来源的持续支持提供便利。这项工作以及随后的GEOTRACES研究的更广泛影响包括更好地了解MMHg在鱼类中积累的形式对人类和生态系统健康的严重威胁。此外，与GEOTRACES一般情况一样，这次相互校准活动将建立和保持国际合作的纽带。最后，在这项工作中的四个PI参与，并在许多情况下寻求额外的杠杆资金，以帮助支持，在本科，研究生和研究生水平的教育工作。

Hg is present at very low concentrations in the open ocean (fM - pM) and is subject to a complex biogeochemical cycling. To understand this cycling, determination of the major species of Hg found in the ocean (mercuric ion, elemental Hg, monomethylHg and dimethylHg; Hg(II), Hgº, MMHg and DMHg, respectively), is necessary but poses daunting analytical challenges. These forms can be volatile and photoactive, and their low concentrations make even small amounts of contamination ruinous. But there are important benefits to studying Hg in the ocean, including increased understanding of the source and bioaccumulation dynamics of a toxic metal, the formation of organometallic compounds (including those of Ge, Se, Po, As) in the ocean, assessing the impact of an anthropogenically mobilized element, and the possible development of a paleoproductivity proxy. With funding from this award, researchers at the Woods Hole Oceanographic Institution, University of Connecticut, Battelle Memorial Institute, and Wright State University will participate in the upcoming GEOTRACES Intercalibration cruises in order to initiate a comprehensive, multi-investigator/laboratory comparison of the determination of mercury (Hg) species in seawater. Such an Intercalibration is a critical first step prior to full fledged GEOTRACES cruise activities, so that the various investigators studying the chemical oceanography of Hg in the context of that project, which is intended to be decentralized and of such scope that no one lab would likely be capable of completing the whole effort, may compare their results. The project will consist of both a shore based and field (participation in the two cruises) components. In the laboratory, the team will test the cleanliness of bottles made from plastics other than Teflon, and the prospects of long-term storage of samples collected during the cruises for total and speciation measurements. This award will support only the field component of the project, with the remaining effort facilitated by on-going support from other sources. The broader impacts of this work, and that of the subsequent GEOTRACES studies, include a greater understanding of a serious human and ecosystem health threat in the form of MMHg accumulation in fish. In addition, and as with GEOTRACES in general, this Intercalibration exercise will forge and maintain bonds of international collaboration. Finally, the four PIs in this effort are engaged in, and in many cases seeking additional leveraging funds to help support, educational efforts at the undergraduate, graduate and post-graduate level.