High-sensitivity tracing of stable isotope labeled Ag nanoparticles in environmental samples using MC-ICP-MS
High-sensitivity tracing of stable isotope labeled Ag nanoparticles in environmental samples using MC-ICP-MS
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DOI：
10.1039/c8ja00358k
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发表时间：
2019-06-01
影响因子：
3.4
通讯作者：
Laycock, Adam
中科院分区：
文献类型：
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作者：
Junk, Tabea;Rehkamper, Mark;Laycock, Adam
银纳米颗粒（Ag NPs）是最广泛使用的工程纳米材料之一，这需要进一步研究它们在环境中的行为和归宿。为了支持这项工作，我们开发了新的技术，用于有效追踪从富集的Ag-109（Ag-En）产生并因此标记的Ag NPs。该方法包括从样品基质中一步阴离子交换分离Ag，并通过多收集器ICP-MS精确测定Ag-109/Ag-107比率和Ag-109丰度。样品制备程序的Ag产率为104 +/- 13%（1 SD），程序Ag空白小于7 pg，从而能够分析仅含痕量Ag的样品。银溶液和实际样品的分析表明，仔细校正记忆效应是至关重要的，以确保数据质量。使用适当的程序，Ag-109/Ag-107比率的样品含有Ag-En可以确定的精度和正确度优于约0.5%，当超过0.5 ng Ag可用于分析。即使Ag仅以50 pg或更少的量存在，样品的Ag同位素比和Ag-En浓度也可以测量到优于5 - 10%。因此，所述方法能够在含有低至10 pg和高达1 ng天然Ag的样品中分辨1 pg Ag-En的存在。因此，即使存在高度可变量的Ag-En和天然Ag，该技术也允许对环境样品中的Ag-En进行稳健的检测和定量。因此，新的方法能够使用稳定同位素示踪来研究银纳米颗粒在复杂环境系统中的命运，其剂量浓度与预测的环境浓度相似，并且对于非常小的样品，同时还提供高的样品通量。
Silver nanoparticles (Ag NPs) are among the most widely used engineered nanomaterials and this warrants further investigation of their behaviour and fate in the environment. To support such work, we developed new techniques for efficient tracing of Ag NPs that are produced from, and hence labelled with, enriched Ag-109 (Ag-En). The methods encompass a one-step anion exchange separation of Ag from the sample matrix and precise determination of Ag-109/Ag-107 ratios and Ag-109 abundances by multiple-collector ICP-MS. The sample preparation procedure has an Ag yield of 104 +/- 13% (1 SD) and a procedural Ag blank of less than 7 pg, enabling analysis of samples with only trace Ag contents. Analyses of Ag solutions and realistic samples show that careful correction of memory effects is paramount for ensuring data quality. Using appropriate procedures, the Ag-109/Ag-107 ratios of samples containing Ag-En can be determined to a precision and trueness of better than about 0.5%, when more than 0.5 ng Ag are available for analysis. Even if Ag is only present at 50 pg or less, the Ag isotope ratios and Ag-En concentrations of samples can be measured to better than 5 to 10%. The methods are therefore able to resolve the presence of 1 pg of Ag-En in samples that contain as little as 10 pg and to up to 1 ng of natural Ag. As such, the techniques allow robust detection and quantification of Ag-En in environmental samples even when highly variable quantities of Ag-En and natural Ag are present. The new methodology thus enables the use of stable isotope tracing to investigate the fate of Ag NPs in complex environmental systems at dosing concentrations similar to the predicted environmental concentrations and for very small samples, whilst also providing high sample throughput.