Copper (Cu) Ligand Distribution Across Multiple Detection Windows in Natural Waters: Influence of pH, DOC Abundance, and Ligand Composition

摘要本奖项由2009年美国复苏与再投资法案（公法111-5）资助。这是第一个在两个湖泊中测量从非常弱到非常强的整个强度范围内的Cu结合配体丰度的研究，将涵盖pH、DOC（溶解有机碳）的数量和组成、营养状况和流域发展水平（包括清洁和污染地点）的范围。化学形态控制金属？自然水域的环境行为和生物有效性。在水生系统中，物种形成主要由金属结合配体控制，金属结合配体通过形成稳定的金属配合物来降低游离（水）金属离子浓度。我假设，天然存在的铜结合水生配体的丰度（[CL]）和稳定性（K?）之间的关系遵循以下形式[CLi] &amp；#61621；K ?i-n，这是由基于O， N和s元素的官能团的相对丰度和强度引起的。这种趋势的分散是由pH和DOC量的变化引起的。CL和K的关系？对强弱配体的相对重要性、游离活性铜（Cu2+）的浓度以及铜的环境行为、毒性和生物利用度都有深远的影响。我将在配体强度(logK？从5到15)，通过一系列分析方法具有多个检测窗口（≥ 5）。DOC组成（O， N， S），还原S配体的重要性，DOC- cl可能的相关性，以及pH的影响都将被测量。最后，我希望评估伪极谱在淡水中测量铜结合配体的效用。

Proposal 0838404AbstractThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This first study to measure Cu binding ligand abundance across the full range of strength from very weak to very strong in two lakes would cover a range of pH, DOC (dissolved organic carbon) amount and composition, trophic status, and level of watershed development (both clean and contaminated sites). Chemical speciation controls a metal?s environmental behavior and biological availability in natural waters. Speciation is largely controlled in aquatic systems by metal-binding ligands that decrease the free (aquo) metal ion concentration through the formation of stable metal complexes. I hypothesize that the relationship between abundance ([CL]) and stability (K?) of naturally occurring, copper-binding, aquatic ligands follows the form [CLi]  K?i-n, and that this is caused by the relative abundance and strength of functional groups based on the elements O, N, and S. Scatter around this trend is introduced by variations in pH and amount of DOC. The relationship between CL and K? has a profound influence on the relative importance of strong and weak ligands, the concentration of free reactive copper (Cu2+), and the environmental behavior, toxicity, and bioavailability of copper. I will test these hypotheses across the full range of ligand strength (logK? from 5 to 15) with multiple detection windows (≥ 5) via a range of analytical methods. DOC composition (O, N, S), the importance of reduced S ligands, a possible DOC-CL correlation, and the influence of pH will all be measured as well. Finally, I hope to evaluate the utility of pseudopolarography for measuring Cu binding ligands in fresh waters.