GEOC 5 |
| Richard D Foust Jr., Molly S Costanza-Robinson, Anne-Marie Compton, and Grant Evans. Department of Chemistry, Northern Arizona University, Flagstaff, AZ 86011-5698 |
| We have investigated the biogeochemical transformations of arsenic in Montezuma Well by collecting organisms from each trophic level and analyzing for total arsenic by atomic absorption spectroscopy and ICP-MS. Sediment, soil, Potamogeton illinoiensis roots, P. illinoiensis leaves, Berula erecta roots, B. erecta leaves, Fissidens grandifrons, Hyallela montezuma, H. azteca, Ranatra montezuma, Telebasis salva, Belostoma bakeri, Motobdella montezuma and DW-rinsed M. montezuma were collected and analyzed. Total arsenic values ranged from 1.0 to 2,810 μg/g (dw). Biodiminution of total arsenic in the littoral zone food web was observed. Total root arsenic levels were higher than leaf arsenic levels. Organisms show different mechanisms for coping with the elevated levels of arsenic found in the Well. The forms of arsenic in the organisms of Montezuma Well as determined by X-ray absorption near edge spectroscopy (XANES) will be reported. Recent work with arbuscular mycorrhizal fungi, and their role in the arsenic uptake in arsenic tolerant plants, will also be discussed. |
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Chemistry of Metals in Terrestrial and Aquatic Systems
8:00 AM-11:25 AM, Sunday, March 28, 2004 Marriott -- Marquis NE, Oral
Division of Geochemistry |