Montaño Manuel D, Cuss Chad W, Holliday Haley M, Javed Muhammad B, Shotyk William, Sobocinski Kathryn L, Hofmann Thilo, Kammer Frank von der, Ranville James F
Department of Environmental Sciences, Western Washington University, Bellingham, Washington 98225, United States.
Department of Renewable Resources, University of Alberta, Edmonton T6G 2H1, Alberta, Canada.
ACS Earth Space Chem. 2022 Apr 21;6(4):943-952. doi: 10.1021/acsearthspacechem.1c00350. Epub 2022 Apr 4.
Nanogeochemistry is an emerging focus area recognizing the role of nanoparticles in Earth systems. Engineered nanotechnology has cultivated advanced analytical techniques that are also applicable to nanogeochemistry. Single particle inductively coupled plasma ICP-time-of-flight-mass spectrometry (ICP-TOF-MS) promises a significant step forward, as time-of-flight mass analyzers enable simultaneous quantification of the entire atomic mass spectrum (∼7-250 / ). To demonstrate the utility of this approach, samples were collected and analyzed from a large, boreal river, and its surrounding tributaries. These samples provided us with a diversity of particle compositions and morphologies, while their interconnected nature allowed for an examination of the various nanogeochemical processes present in this system. To further expand on this effort, we combined this high-throughput technique with AF4-ICPMS, focusing on major carriers of trace elements. Using spICP-TOF-MS, Al, Si, and Fe were grouped into classes having all combinations of one or more of these elements. Particle-by-particle ICP-TOF-MS analysis found chemically heterogeneous populations, indicating the predominance of diverse mineralogy or heteroaggregates. The importance of suspended Fe and Mn for the speciation of Pb was observed by single particle ICP-TOF-MS and complemented by AF4-ICPMS analysis of dissolved organic matter and nanoparticulate Fe/Mn. Our study exploits the combination of spICP-TOF-MS and AF4-ICP-MS for studying isotopic and elemental ratios (mineralogy) of individual nanoparticles, which opens the door to further explore the mechanisms of colloid facilitated transport of trace elements.
纳米地球化学是一个新兴的重点研究领域，它认识到纳米颗粒在地球系统中的作用。工程纳米技术催生了先进的分析技术，这些技术也适用于纳米地球化学。单颗粒电感耦合等离子体质谱仪（ICP-TOF-MS）有望向前迈出重要一步，因为飞行时间质量分析仪能够同时对整个原子质谱（约7-250 / ）进行定量分析。为了证明这种方法的实用性，我们从一条大型北方河流及其周边支流采集并分析了样本。这些样本为我们提供了多样的颗粒组成和形态，同时它们的相互连接性质使我们能够研究该系统中存在的各种纳米地球化学过程。为了进一步拓展这项工作，我们将这种高通量技术与AF4-ICPMS相结合，重点关注微量元素的主要载体。使用spICP-TOF-MS，将铝、硅和铁分为含有这些元素中一种或多种元素所有组合的类别。逐颗粒ICP-TOF-MS分析发现了化学性质不均匀的群体，这表明存在多种矿物学或异质聚集体。单颗粒ICP-TOF-MS观察到悬浮的铁和锰对铅形态的重要性，并通过对溶解有机物和纳米颗粒铁/锰的AF4-ICPMS分析得到补充。我们的研究利用spICP-TOF-MS和AF4-ICP-MS的组合来研究单个纳米颗粒的同位素和元素比率（矿物学），这为进一步探索微量元素胶体促进传输的机制打开了大门。
