Collaborative Research: Changing the manganese paradigm

University Of Delaware, Newark DE

Investigators

Abstract

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.