Institute of Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA, Leiden, the Netherlands.
Institute of Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA, Leiden, the Netherlands.
Environ Pollut. 2019 Dec;255(Pt 2):113304. doi: 10.1016/j.envpol.2019.113304. Epub 2019 Sep 26.
Suitable methods and fit-for-purpose techniques are required to allow characterization of carbon-based nanomaterials (CB-NMs) in complex matrices. In this study, two methods were developed; a method for extraction and characterization of CB-NMs in biological media and a method for fractionation of natural organic matter (NOM) coated CB-NMs in environmental matrices. The former method was developed by extracting carbon nanotubes (CNTs: sized 0.75 × 3000 nm) and nanoplastics (sized 60, 200 and 600 nm) from eggshells and characterizing the extracted CB-NMs in terms of particle size distribution using asymmetrical flow field-flow fractionation (AF4) coupled with multi-angle light scattering (MALS). The latter method was developed using AF4-MALS to fraction NOM-coated CNT (sized 0.75 × 3000 nm) and nanoplastics (sized 60, 200 and 300 nm) in a simulated natural surface water and provide information about the size distribution of the CB-NM-NOM complexes. The developed AF4-MALS method successfully fractioned the CB-NM-NOM complexes based on hydrodynamic size and provided the size distribution of the complexes. The NOM corona did not shift significantly the median size of the CB-NMs. It influenced however the size distribution of the nanoplastics and CNTs. The sample preparation method failed to extract the CNTs (recovery < 20%) from the matrices of the eggshells while being successful for extracting the nanoplastics (recoveries > 60%). The AF4-MALS fractogram showed that the extraction method did not significantly influence the size distribution of the nanoplastics of 60 and 200 nm size, whereas the peak of 600 nm nanoplastics shifted towards a smaller hydrodynamic size. In conclusion, the developed sample preparation method followed by the developed AF4-MALS method can be applied for extraction, separation and characterization of CB-NMs in biological and environmental matrices. Thus, the methods have a high potential to be methods of choice to investigate CB-NMs in future studies.
需要合适的方法和适用技术来对碳基纳米材料（CB-NMs）在复杂基质中的特性进行描述。本研究开发了两种方法；一种是用于从生物介质中提取和表征 CB-NMs 的方法，另一种是用于对环境基质中天然有机物（NOM）涂覆的 CB-NMs 进行分级的方法。前者的方法是通过从蛋壳中提取碳纳米管（CNT：尺寸为 0.75×3000nm）和纳米塑料（尺寸为 60、200 和 600nm），并使用不对称流场流分离（AF4）与多角度光散射（MALS）联用，对提取的 CB-NMs 的粒径分布进行表征来开发的。后者的方法是使用 AF4-MALS 来对模拟天然地表水中涂覆有 NOM 的 CNT（尺寸为 0.75×3000nm）和纳米塑料（尺寸为 60、200 和 300nm）进行分级，并提供有关 CB-NM-NOM 复合物的粒径分布信息。开发的 AF4-MALS 方法成功地根据流体力学尺寸对 CB-NM-NOM 复合物进行了分级，并提供了复合物的粒径分布。NOM 冠层没有显著改变 CB-NM 的中值粒径。然而，它影响了纳米塑料和 CNT 的粒径分布。该样品制备方法无法从蛋壳基质中提取 CNT（回收率<20%），但成功提取了纳米塑料（回收率>60%）。AF4-MALS 馏分图显示，该提取方法并未显著影响 60nm 和 200nm 尺寸的纳米塑料的粒径分布，而 600nm 纳米塑料的峰则向较小的流体力学尺寸移动。总之，所开发的样品制备方法结合所开发的 AF4-MALS 方法可用于生物和环境基质中 CB-NMs 的提取、分离和表征。因此，这些方法具有很高的潜力成为未来研究中选择的 CB-NMs 研究方法。
