Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado, USA.
Environ Toxicol Chem. 2012 Jan;31(1):93-9. doi: 10.1002/etc.708.
Increasing manufacture and use of engineered nanoparticles is leading to a greater probability for release of engineered nanoparticles into the environment and exposure to organisms. In particular, zinc oxide (ZnO) is toxic, although it is unclear whether this toxicity is due to the zinc oxide nanoparticles, dissolution to Zn(2+) , or some combination thereof. The goal of this study was to determine the relative solubilities of both commercially available and in-house synthesized ZnO in matrices used for environmental fate and transport or biological toxicity studies. Dissolution of ZnO was observed in nanopure water (7.18-7.40 mg/L dissolved Zn, as measured by filtration) and Roswell Park Memorial Institute medium (RPMI-1640) (∼5 mg/L), but much more dissolution was observed in Dulbecco's modified Eagle's medium, in which the dissolved Zn concentration exceeded 34 mg/L. Moderately hard water exhibited low Zn solubility, likely because of precipitation of a Zn carbonate solid phase. Precipitation of a Zn-containing solid phase in RPMI also appeared to limit Zn solubility. Equilibrium conditions with respect to ZnO solubility were not apparent in these matrices, even after more than 1,000 h of dissolution. These results suggest that solution chemistry exerts a strong influence on ZnO dissolution and can result in limits on Zn solubility from precipitation of less soluble solid phases.
随着工程纳米粒子的制造和使用不断增加，工程纳米粒子释放到环境中并暴露于生物体的可能性也越来越大。特别是氧化锌（ZnO）是有毒的，尽管尚不清楚这种毒性是由于氧化锌纳米粒子、溶解为 Zn(2+)还是两者的某种组合。本研究的目的是确定商业上可获得的和内部合成的 ZnO 在用于环境归宿和传输或生物毒性研究的基质中的相对溶解度。在纳米纯水中观察到 ZnO 的溶解（通过过滤测量的溶解 Zn 为 7.18-7.40 mg/L）和罗格斯大学纪念研究所培养基（RPMI-1640）（约 5 mg/L），但在杜尔贝科改良伊格尔培养基中观察到更多的溶解，其中溶解 Zn 浓度超过 34 mg/L。中等硬度的水表现出低的 Zn 溶解度，可能是因为形成了 Zn 碳酸盐固相。RPMI 中的 Zn 含固相的沉淀似乎也限制了 Zn 的溶解度。即使在溶解超过 1000 小时后，这些基质中仍未出现 ZnO 溶解度的平衡条件。这些结果表明，溶液化学对 ZnO 的溶解有很强的影响，并可能导致由于形成溶解度较低的固相而限制 Zn 的溶解度。
