Aramendía Maite, Leite Diego, Resano Javier, Resano Martín, Billimoria Kharmen, Goenaga-Infante Heidi
Department of Analytical Chemistry, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain.
Department of Computer Sciences and Systems Engineering (DIIS), Aragón Institute of Engineering Research (I3A), University of Zaragoza, C/Mariano Esquillor SN, 50018 Zaragoza, Spain.
Nanomaterials (Basel). 2023 Aug 22;13(17):2392. doi: 10.3390/nano13172392.
This paper describes methodology based on the application of isotope dilution (ID) in single-particle inductively coupled plasma time-of-flight mass spectrometry (spICP-ToFMS) mode for the mass determination (and sizing) of silver nanoparticles (AgNPs). For this purpose, and considering that the analytical signal in spICP-MS shows a transient nature, an isotope dilution equation used for online work was adapted and used for the mass determination of individual NPs. The method proposed measures NP isotope ratios in a particle-to-particle approach, which allows for the characterization of NP mass (and size) distributions and not only the mean size of the distribution. For the best results to be obtained, our method development (undertaken through the analysis of the reference material NIST RM 8017) included the optimization of the working conditions for the best precision and accuracy in isotope ratios of individual NPs, which had been only reported to date with multicollector instruments. It is shown that the precision of the measurement of these ratios is limited by the magnitude of the signals obtained for each NP in the mass analyzer (counting statistics). However, the uncertainty obtained for the sizing of NPs in this approach can be improved by careful method optimization, where the most important parameters are shown to be the selection of the spike isotopic composition and concentration. Although only AgNPs were targeted in this study, the method presented, with the corresponding adaptations, could be applied to NPs of any other composition that include an element with different naturally available isotopes.
本文描述了基于同位素稀释（ID）在单颗粒电感耦合等离子体飞行时间质谱（spICP-ToFMS）模式下用于银纳米颗粒（AgNPs）质量测定（和尺寸分析）的方法。为此，考虑到spICP-MS中的分析信号具有瞬态性质，对用于在线工作的同位素稀释方程进行了调整，并用于单个纳米颗粒的质量测定。所提出的方法以逐个颗粒的方式测量纳米颗粒的同位素比率，这不仅能够表征纳米颗粒质量（和尺寸）分布的平均值，还能对其分布进行表征。为了获得最佳结果，我们的方法开发（通过对参考物质NIST RM 8017的分析进行）包括优化工作条件，以实现单个纳米颗粒同位素比率的最佳精度和准确性，迄今为止这仅在多接收器仪器上有报道。结果表明，这些比率测量的精度受质量分析器中每个纳米颗粒获得的信号强度（计数统计）限制。然而，通过仔细的方法优化可以提高这种方法中纳米颗粒尺寸分析的不确定性，其中最重要的参数是加标同位素组成和浓度的选择。尽管本研究仅针对AgNPs，但所提出的方法经过相应调整后，可应用于任何其他包含具有不同天然可用同位素元素的纳米颗粒。
