Mass-Independent Fractionation of Mercury Isotopes in Freshwater Systems
Mass-independent fractionation (MIF) of Hg isotopes has the potential to track the environmental transport and fate of Hg. Herein we demonstrate that reducing both the frequency and intensity of light have a large effect on the expression and magnitude of MIF. This strongly supports the magnetic iso...
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| Format: | Dissertation |
| Language: | English |
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ProQuest Dissertations & Theses
01-01-2010
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| Online Access: | Get full text |
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| Summary: | Mass-independent fractionation (MIF) of Hg isotopes has the potential to track the environmental transport and fate of Hg. Herein we demonstrate that reducing both the frequency and intensity of light have a large effect on the expression and magnitude of MIF. This strongly supports the magnetic isotope effect as the mechanism behind MIF observed during aqueous photo-reduction of Hg(II) and MeHg. The ratios of MIF, Δ199Hg/Δ 201Hg, were 1.00 ± 0.04 (2SE) for Hg(II) and 1.35 ± 0.16 (2SE) for MeHg respectively and did not change as incident radiation energy and magnitude of MIF diminished, suggesting the respective MIF pathways remained constant regardless of experimental conditions. Comparable amounts of total photo-reduction were shown to coincide with different magnitudes of MIF depending the wavelength light available for photo-reduction. This confirms there are multiple pathways for photo-reduction in freshwater reservoirs and indicates that quantitatively relating photo-reduction and MIF will be challenging. |
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| ISBN: | 049485460X 9780494854600 |