Wasmuth Claus, Rüdel Heinz, Düring Rolf-Alexander, Klawonn Thorsten
Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Auf dem Aberg 1, 57392 Schmallenberg, Germany.
Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Auf dem Aberg 1, 57392 Schmallenberg, Germany.
Chemosphere. 2016 Feb;144:2018-23. doi: 10.1016/j.chemosphere.2015.10.101. Epub 2015 Nov 12.
The OECD guidance document No. 29 was designed to determine the rate and extend to which metals can produce soluble available ionic metal species. This transformation/dissolution protocol was applied to silver nanomaterials. The results prove that concentrations of released Ag(+) at pH 8 were nearly similar at all three different loadings. At pH 6, the concentration of Ag(+) was almost the same at loadings of 10 and 100 mg L(-1) AgNPs. However, the study showed changes in concentrations of nanoparticles and aggregates (operationally defined as the fraction passing a 0.2 µm filter). At the higher pH both the concentrations in the test medium of Ag(+) and of AgNPs (fraction < 0.2 µm) decreased. After 7 days of test duration, 71 µg L(-1) of Ag(+) was found in pH 6 medium (initial loading of 100 mg L(-1)). In pH 8 medium a maximum concentration of 29 µg L(-1) Ag(+) was measured (initial loading of 10 mg L(-1)). The maximum transformation from AgNPs to Ag(+) was 2.7% (27 µg L(-1)) in pH 8 medium (loading of 1 mg L(-1)) after 7 days. At an initial loading of 100 mg L(-1) AgNPs in medium at pH 8, only 0.03% (30 µg L(-1)) were transformed to Ag(+) after 7 days. At the loading of 1 mg L(-1) AgNPs all silver concentrations remain relatively constant for the duration of the test after 7 until 28 days. The results reveal that only low concentrations of Ag(+) are released from AgNPs under the applied conditions.
经合组织第29号指导文件旨在确定金属产生可溶性可用离子金属物种的速率和程度。该转化/溶解方案应用于银纳米材料。结果证明，在所有三种不同负载量下，pH值为8时释放的Ag(+)浓度几乎相似。在pH值为6时，10和100 mg L(-1) AgNPs负载量下的Ag(+)浓度几乎相同。然而，该研究显示了纳米颗粒和聚集体浓度的变化（操作上定义为通过0.2 µm过滤器的部分）。在较高pH值下，测试介质中Ag(+)和AgNPs（部分<0.2 µm）的浓度均降低。测试持续7天后，在pH值为6的介质中（初始负载量为100 mg L(-1)）发现了71 µg L(-1)的Ag(+)。在pH值为8的介质中，测得的Ag(+)最大浓度为29 µg L(-1)（初始负载量为10 mg L(-1)）。7天后，在pH值为8的介质中（负载量为1 mg L(-1)），从AgNPs到Ag(+)的最大转化率为2.7%（27 µg L(-1)）。在pH值为8的介质中，初始负载量为100 mg L(-1) AgNPs时，7天后只有0.03%（30 µg L(-1)）转化为Ag(+)。在1 mg L(-1) AgNPs的负载量下，在7至28天的测试期间，所有银浓度保持相对恒定。结果表明，在所应用的条件下，只有低浓度的Ag(+)从AgNPs中释放出来。
