Determination of Mercury (II) and Nitrate Concentrations in Natural Waters Using Ion-Selective Electrodes and Atomic Emission Spectroscopy

Date of Graduation

Summer 2006

Degree

Master of Science in Chemistry

Department

Chemistry and Biochemistry

Committee Chair

Erich Steinle

Abstract

With the danger that mercury (II) ions pose to living organisms and the excessive algae growth in natural waters caused by nitrate (NO3-) ions, having fast and reliable detection methods for each ion would be beneficial. Ion-selective electrodes have the potential to be effective sensors because they are relatively inexpensive as compared to other instruments and are portable. These electrodes become selective to certain ions within a compound, called an ionophore, is added to the polymer membrane located in the tip of the electrode. Ionophores bind to certain ions more readily than others, providing a way for specific ions to enter the organic membrane from the aqueous sample solution. The voltage difference created as a result of this transfer process can be correlated directly to ion concentration. The first part of this research project will be to determine with ionophore is most selective for each ion and to construct electrodes based on those results. Water samples will then be collected from sites near coal power plants, which are a source of mercury emissions. Other sites of interest in the Springfield area will also be examined for both ions of interest. The samples will be tested using the constructed electrodes and observed mercury concentrations will be compared with an established method, atomic emission spectroscopy. If these new electrodes are accurate, examinations of local waters could be much faster with fewer steps as compared to standard methods.

Keywords

electrode, mercury, nitrate, ionophore, ion-selective electrode, ICP-AES

Subject Categories

Chemistry

Copyright

© Christopher Kabonic

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Dissertation/Thesis

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