Institute of Environmental Sciences (CML), Leiden University, Leiden 2300 RA, the Netherlands.
College of Environment, Zhejiang University of Technology, Hangzhou 310032, PR China.
Ecotoxicol Environ Saf. 2022 Sep 1;242:113920. doi: 10.1016/j.ecoenv.2022.113920. Epub 2022 Jul 26.
The goal of the current study was to quantify the trophic transfer of copper nanoparticles (CuNPs) in a food chain consisting of the microalga Pseudokirchneriella subcapitata as the representative of primary producer, the grazer Daphnia magna, and the omnivorous mysid Limnomysis benedeni. To quantify the size and number concentration of CuNPs in the biota, tissue extraction with tetramethylammonium hydroxide (TMAH) was performed and quantification was done by single particle inductively coupled plasma mass spectrometry (sp-ICP-MS). The bioconcentration factor (BCF) of the test species for CuNPs varied between 10 - 10 L/kg dry weight when expressing the internal concentration on a mass basis, which was lower than BCF values reported for Cu (10 - 10 L/kg dry weight). The particle size of CuNPs determined by sp-ICP-MS ranged from 22 to 40 nm in the species. No significant changes in the particle size were measured throughout the food chain. Moreover, the measured number of CuNPs in each trophic level was in the order of 10 particles/kg wet weight. The calculated trophic transfer factor (mass concentration basis) was > 1. This indicates biomagnification of particulate Cu from P. subcapitata to L. benedeni. It was also found that the uptake of particulate Cu (based on the particle number concentration) was mainly from the dietary route rather than from direct aqueous exposure. Furthermore, dietary exposure to CuNPs had a significant effect on the feeding rate of mysid during their transfer from daphnia to mysid and from alga through daphnia to mysid. This work emphasizes the importance of tracing the particulate fraction of metal-based engineered nanoparticles when studying their uptake and trophic transfer.
本研究的目的是量化食物链中铜纳米粒子（CuNPs）的营养传递，该食物链由微藻假鱼腥藻作为初级生产者，食草动物大型溞和杂食性糠虾Limnomysis benedeni 组成。为了量化生物体内 CuNPs 的大小和数量浓度，采用四甲基氢氧化铵（TMAH）进行组织提取，并通过单颗粒电感耦合等离子体质谱（sp-ICP-MS）进行定量。当以质量为基础表达内部浓度时，测试物种对 CuNPs 的生物浓缩因子（BCF）在 10 - 10 L/kg 干重之间变化，低于报道的 Cu 的 BCF 值（10 - 10 L/kg 干重）。sp-ICP-MS 测定的 CuNPs 粒径在物种中范围为 22 至 40nm。在整个食物链中，未测量到粒径的显著变化。此外，在每个营养级测量到的 CuNPs 数量均为 10 个/公斤湿重。计算的营养传递因子（质量浓度基础）大于 1。这表明从假鱼腥藻到糠虾的颗粒状 Cu 的生物放大作用。还发现，基于颗粒数浓度的颗粒状 Cu 的吸收主要来自饮食途径，而不是直接水暴露。此外，膳食暴露于 CuNPs 对糠虾从大型溞到糠虾以及从藻类通过大型溞到糠虾的转移过程中的摄食率有显著影响。这项工作强调了在研究金属基工程纳米粒子的摄取和营养传递时，追踪金属基工程纳米粒子的颗粒部分的重要性。
