Binding of methylmercury compounds by humic and fulvic acids
Binding of methylmercury compounds by humic and fulvic acids
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腐殖酸和黄腐酸与甲基汞化合物的结合
DOI：
10.1007/bf01189760
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
R. D. Evans
中科院分区：
文献类型：
--
作者：
H. Hintelmann;P. Welbourn;R. D. Evans
腐植酸和黄腐酸是从安大略省的 Fawn Lake 中分离出来的，并通过膜透析研究了它们结合 CH3Hg+ 的能力。通过测量甲基汞化合物在透析膜内外的分布，首次可以计算出 CH3Hg+ 和腐殖酸的结合能力和条件稳定性常数。内部和外部透析溶液在24小时内达到平衡，腐殖溶液中的CH3Hg+没有损失。随着系统中总 CH3Hg+ 水平的降低，结合与未结合 CH3Hg+ 的比率增加。游离甲基汞化合物的百分比随着pH值的降低而增加。小鹿湖腐植酸显示出两个不同的结合位点。较强位点的条件稳定常数经计算为 1.3 × 1012。该位点每毫克腐殖酸能够结合 0.2 ng CH3Hg+。
Humic and fulvic acids were isolated from Fawn Lake in Ontario and investigated by membrane dialysis for their ability to bind CH3Hg+. By measuring the distribution of methylmercury compounds in and outside of the dialysis membrane, for the first time, binding capacities and conditional stability constants for CH3Hg+ and humic acids could be calculated. Equilibrium between inner and outer dialysis solution was reached within 24 hours without losses of CH3Hg+ in humic solution. The ratio of bound to unbound CH3Hg+ increased with decreasing total CH3Hg+ levels in the system. The percentage of free methylmercury compounds increased with decreasing pH. Fawn Lake humic acid showed two different binding sites. The conditional stability constant of the stronger site was calculated as 1.3 × 1012. This site was able to bind 0.2 ng CH3Hg+ per mg of humic acid.