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2006 Annual Science Report

University of Hawaii, Manoa Reporting  |  JUL 2005 – JUN 2006

Analysis Software for in Situ Voltammetry

4 Institutions
3 Teams
0 Publications
0 Field Sites
Field Sites

Project Progress

In situ measurements are necessary to understand dynamic environments where chemical speciation can change within seconds, or millimeters as a result of chemical, biological, or physical processes. Recent efforts have produced reliable techniques for using voltammetric micro-electrodes to measure a variety of redox species in real time from a variety of environments, including hydrothermal vents, microbial mats and biofilms, coastal sediments, estuarine and oceanic water columns and laboratory environments. Each redox species produces a current peak that can be discriminated from others in one potential scan from —0.1 V to —2.0 V (analogous to varying wavelength and measuring absorbance with spectroscopy). Dr. Brian Glazer, a UH-NAI postdoctoral fellow, is an expert on in situ electrochemical voltammetric techniques.

Although extremely valuable, these techniques have in the past required many hours of human analysis. Each micro-electrode must be calibrated over a range of known measurements, requiring a human to identify peaks and measure peak heights for each calibration point. A human must also identify peaks and heights in field data, and weed out any flawed data. All of these processes are time-consuming and prone to inconsistencies due to slight variations in peak identification and measurement heuristics between researchers.

In this project, we have built a system to automate this process as much as possible. The system quickly identifies peaks and peak heights in a consistent manner, and performs micro-electrode calibrations, while also allowing a researcher to intervene and identify flawed data. Two MSc students in the Information and Computer Sciences Department have developed the first version of this software, which will be tested and expanded over the next six months. The next stage is to build on-board software, to do a partial analysis of the data during collection, so that the device can automatically re-take problematic data, or focus in on areas of particular interest.