European Commission, Joint Research Centre (JRC), 2440, Geel, Belgium.
European Commission, EUROSTAT, 2920, Luxembourg, Luxembourg.
Anal Bioanal Chem. 2021 Jan;413(1):141-157. doi: 10.1007/s00216-020-02984-z. Epub 2020 Oct 13.
A new certified reference material (CRM) for size and shape analysis of elongated nanoparticles has been developed by the European Commission's Joint Research Centre. The CRM consists of titanium dioxide nanorods dispersed in 1-butanol, was coded ERM-FD103 and has been certified for different electron microscopy-based operationally defined measurands such as the modal and median values of the particle number-weighted distributions of the minimum and maximum Feret diameter, the maximum inscribed circle diameter, the area-equivalent circular diameter and the aspect ratio. The nanorods have nominal dimensions of 15 nm in width and 55 nm in length. Homogeneity and stability measurements were performed using transmission electron microscopy. The relative standard uncertainty for homogeneity ranged from 0.3 to 1.7%. No significant instability was detected for a shelf life of 18 months and a storage temperature of 18 °C. The certified values have been determined from the results of an interlaboratory comparison in which qualified expert laboratories participated with scanning and transmission electron microscopy. The certified values are traceable to the unit of length in the International System of Units, the metre, and the relative expanded uncertainties (confidence level of approximately 95%) range from 4 to 6%. These properties allow the CRM to be used for quality assurance and calibration of electron microscopy methods for nanoparticle size and shape analysis in ranges relevant for the implementation of EU legislation related to nanomaterials. The presented study discusses the purpose and results of the different steps that were followed to turn an industrially relevant raw titanium dioxide nanorod material into a fit-for-purpose CRM.Graphical abstract.
欧盟委员会联合研究中心开发了一种新的认证参考物质 (CRM)，用于分析长形纳米粒子的大小和形状。该 CRM 由分散在 1-丁醇中的二氧化钛纳米棒组成，编号为 ERM-FD103，并已针对不同基于电子显微镜的操作定义可测量值进行了认证，例如最小和最大 Feret 直径、最大内切圆直径、面积等效圆形直径和纵横比的颗粒数加权分布的模态值和中位数。纳米棒的标称尺寸为 15nm 宽和 55nm 长。使用透射电子显微镜进行了均匀性和稳定性测量。均匀性的相对标准不确定度范围为 0.3 至 1.7%。在 18°C 的储存温度和 18 个月的货架寿命下，未检测到明显的不稳定性。认证值是从具有扫描和透射电子显微镜资格的专家实验室参与的实验室间比较的结果中确定的。认证值可追溯到国际单位制中的长度单位米，相对扩展不确定度（置信水平约为 95%）范围为 4 至 6%。这些特性允许 CRM 用于纳米粒子大小和形状分析的电子显微镜方法的质量保证和校准，这些方法适用于实施与纳米材料相关的欧盟法规的相关范围。本研究讨论了将工业相关的原始二氧化钛纳米棒材料转化为适用的 CRM 所遵循的不同步骤的目的和结果。
