Evaluation of the effect of reactive sulfide on the acute toxicity of silver (I) to Daphnia magna. Part 2: Toxicity results
Evaluation of the effect of reactive sulfide on the acute toxicity of silver (I) to Daphnia magna. Part 2: Toxicity results
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活性硫化物对银（I）对大型溞急性毒性影响的评价。
DOI：
10.1002/etc.5620210626
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发表时间：
2002
影响因子：
4.1
通讯作者：
C. Wood
中科院分区：
文献类型：
--
作者：
A. Bianchini;K. Bowles;C. Brauner;J. Gorsuch;J. R. Kramer;C. Wood
研究了活性硫化物对AgNO 3对大型蚤（Daphnia magna）幼仔毒性的保护作用。急性（48-h）毒性试验是在缺氧条件下，在不存在（<5 nM）和存在低浓度（> 25 nM）和高浓度（> 250 nM）硫化锌簇的情况下进行的。在存在和不存在硫化物的情况下，与计算中使用的标称银浓度相比，测量时观察到较低的平均致死浓度（LC 50）值。这反映了以下事实：由于实验期间观察到溶液中的银损失，测得的总银浓度低于标称浓度。高浓度（约250 nM）的硫化物可完全防止毒性，直至测试的最高银浓度（2 μg/L [19 nM]），并测量了银数据。在接受沃茨中存在环境现实水平的硫化物（≤ 25 nM）的情况下，急性银毒性降低约5.5倍。然而，当仅考虑过滤后（0.45 μm）的银浓度时，在不存在（0.22 μg/L）和存在（0.28 μg/L）硫化物的情况下，毒性（48 h LC 50）相似。测得的总银和过滤后的银之间的差异归因于金属硫化物化学吸附到膜过滤器上，并提供证据表明银的毒性部分是未与硫化物结合的部分。银的积累是更大的水蚤暴露于银在硫化物的存在下比在它的情况下，即使在这些条件下没有观察到的毒性作用。在这种情况下，银似乎是由水蚤结合而不是仅仅吸附在表面上。我们的研究结果指出，需要将硫化物纳入急性生物配体模型，并评估其潜在的巨大作用，在预防慢性毒性。
The protective effect of reactive sulfide against AgNO3 toxicity to Daphnia magna neonates was studied. Acute (48‐h) toxicity tests were performed in the absence (<5 nM) and presence of low (∼25 nM) and high (∼250 nM) concentrations of zinc sulfide clusters under oxic conditions. In both the presence and the absence of sulfide, lower mean lethal concentration (LC50) values were observed when measured as opposed to nominal silver concentrations were used in calculations. This reflected the fact that measured total silver concentrations were lower than nominal concentrations due to losses of silver from solution observed during the experiment. High concentration (∼250 nM) of sulfide completely protected against toxicity up to the highest silver concentration tested (2 μg/L [19 nM]) with measured silver data. In the presence of environmentally realistic levels of sulfide (∼25 nM) in receiving waters, acute silver toxicity was reduced by about 5.5‐fold. However, when filtered (0.45 μm) silver concentrations alone were considered, toxicity (48‐h LC50) was similar in the absence (0.22 μg/L) and presence (0.28 μg/L) of sulfide. The difference between measured total and filtered silver was attributed to chemisorption of the metal sulfide onto the membrane filter and provides evidence that the toxic fraction of silver is that which is unbound to sulfide. Accumulation of silver was greater in daphnids exposed to silver in the presence of sulfide than in its absence, even though a toxic effect was not observed under these conditions. In this case, silver appears to be incorporated by daphnids rather than merely adsorbed on the surface. Our results point out the need to incorporate sulfide into the acute biotic ligand model and to assess its potentially large role in preventing chronic toxicity.