Collaborative Research: Changing the manganese paradigm

该项目由特拉华大学和俄勒冈健康与科学大学的研究人员合作开展，将开发一种灵敏的方法，用于在含氧环境和还原区测量海水中亚纳摩尔水平的总锰和锰（III）浓度。该方法是对已有方法的改进，具有nM灵敏度。这项为期一年的项目的主要目标是提高该方法的检测限，并证明其在环境水平（0.5 nM）下测量Mn（III）的能力。将调查两种不同的方法，初步证据表明这两种方法都是可行的选择。使用长路径光学电池将增加当前检测系统的灵敏度，而预浓缩是另一种可以使用的方法。另一种选择是使用荧光检测，这也将进行研究。将使用参考材料对各种方法进行测试，包括在最近的海洋学相互校准活动中收集的参考材料。此外，这些方法将在短途巡航和实验室培养实验中进行测试。更广泛的影响：锰氧化还原化学影响许多全球生物地球化学循环，因此了解这些相互作用具有广泛的意义。该项目将培训研究生，其成果将通过若干教育和公共宣传活动传播。这项研究将继续在以前资助的工作中开展的国际合作。

The project, a collaboration between investigators at the University of Delaware and Oregon Health and Science University, will develop a sensitive method for measuring the concentration of total Mn and Mn(III) at sub-nanomolar levels in ocean waters, both in oxic environments and in reduced zones. The proposed method is a modification of a published method, which has nM sensitivity. The improvement in the detection limit of this method and the demonstration of its ability to measure Mn(III) at environmental levels (0.5 nM)is the major goal of this one year project. Two different approaches will be investigated, and preliminary evidence suggests that both approaches are viable alternatives. Use of a long path optical cell will increase sensitivity of the current detection system, and preconcentration is another approach that can be used. An alternative is the use of fluorescence detection, and this will also be investigated. The various methods will be tested using referrence materials, including those collected during recent oceanographic intercalibration exercises. Additionally, the methods will be tested during short cruises and through laboratory culture experiments.Broader Impacts: Manganese redox chemistry impacts a number of global biogeochmeical cycles, and therefore understanding these interactions has broad implications. The project will train graduate students, and the results will be desseminated through a number of educational and public outreach activities. This research will continue international collaborations developed during previously funded work.