State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment ; ‡Lab of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, P. R. China.
Environ Sci Technol. 2013;47(21):12524-31. doi: 10.1021/es403230u. Epub 2013 Oct 24.
Graphene layers are potential candidates in a large number of applications. However, little is known about their ecotoxicological risks largely as a result of a lack of quantification techniques in complex environmental matrices. In this study, graphene was synthesized by means of graphitization and exfoliation of sandwich-like FePO4/dodecylamine hybrid nanosheets, and (14)C was incorporated in the synthesis. (14)C-labeled graphene was spiked to artificial freshwater and the uptake and depuration of graphene by Daphnia magna were assessed. After exposure for 24 h to a 250 μg/L solution of graphene, the graphene concentration in the organism was nearly 1% of the organism dry mass. These organisms excreted the graphene to clean artificial freshwater and achieved roughly constant body burdens after 24 h depuration periods regardless of the initial graphene exposure concentration. Addition of algae and humic acid to water during the depuration period resulted in release of a significant fraction (>90%) of the accumulated graphene, but some still remained in the organism. Accumulated graphene in adult Daphnia was likely transferred to the neonates. The uptake and elimination results provided here support the environmental risk assessment of graphene and the graphene quantification method is a powerful tool for additional studies.
石墨烯层在大量应用中是潜在的候选者。然而，由于缺乏在复杂环境基质中定量的技术，对其生态毒理学风险知之甚少。在这项研究中，通过三明治状 FePO4/十二胺混合纳米片的石墨化和剥离来合成石墨烯，并在合成中掺入 (14)C。将 (14)C 标记的石墨烯添加到人工淡水中，评估了大腹圆顶蚤对石墨烯的吸收和净化。在暴露于 250 μg/L 浓度的石墨烯溶液 24 h 后，石墨烯在生物体中的浓度接近生物体干重的 1%。这些生物体排泄出石墨烯，以清洁人工淡水，并在 24 h 的净化期后，无论初始石墨烯暴露浓度如何，都能达到大致恒定的体负荷。在净化期间向水中添加藻类和腐殖酸会导致积累的石墨烯的很大一部分（>90%）释放，但仍有一些留在生物体中。成年大腹圆顶蚤积累的石墨烯可能转移到幼体中。这里提供的吸收和消除结果支持对石墨烯的环境风险评估，并且石墨烯定量方法是进一步研究的有力工具。
