Gschwind Sabrina, Aja Montes Maria de Lourdes, Günther Detlef
Department of Chemistry and Applied Biosciences, Laboratory of Inorganic Chemistry, ETH Zurich, Vladimir-Prelog Weg 1, 8093, Zürich, Switzerland.
Anal Bioanal Chem. 2015 May;407(14):4035-44. doi: 10.1007/s00216-015-8620-7. Epub 2015 Mar 22.
In 2011, the European Commission introduced new regulations on how nanomaterials are defined. Since then, researchers have emphasized that more complete characterization of nanoparticles (NPs) includes not just mass and size determinations, but also the determination of the particle number concentrations. In this study, two different sample introduction approaches for the analysis of NP suspensions with inductively coupled plasma mass spectrometry (ICP-MS) were investigated: pneumatic nebulization (sp-ICP-MS) and microdroplet generation (MDG-ICP-MS). These approaches were compared for the determination of particle number concentrations (PNCs) of gold and silver NP suspensions diluted in either ultra-pure water or citrate solution. For accurate sp-ICP-MS analysis, it is crucial to know the transport efficiency of nebulized sample into the plasma. Here, transport efficiencies, measured by the waste collection method, were 11-14 % for Ag suspensions and 9-11 % for Au. In contrast, the droplet transport efficiency of MDG-ICP-MS was 100 %. Analysis by sp-ICP-MS yielded a lower particle number concentration than expected (only 20-40 % of the expected value), whereas MDG-ICP-MS had NP recoveries up to 80 %. This study indicates that NP reference materials are of major importance for particle number determination and detailed results on particle number concentrations for different suspensions with respect to storage time are discussed.
2011年，欧盟委员会出台了关于纳米材料定义的新规定。自那时起，研究人员强调，对纳米颗粒（NP）更全面的表征不仅包括质量和尺寸测定，还包括颗粒数浓度的测定。在本研究中，对两种用于电感耦合等离子体质谱（ICP-MS）分析NP悬浮液的不同进样方法进行了研究：气动雾化（sp-ICP-MS）和微滴生成（MDG-ICP-MS）。比较了这两种方法用于测定稀释在超纯水或柠檬酸盐溶液中的金和银NP悬浮液的颗粒数浓度（PNC）。对于准确的sp-ICP-MS分析，了解雾化样品进入等离子体的传输效率至关重要。在此，通过废物收集法测得的传输效率，银悬浮液为11 - 14%，金悬浮液为9 - 11%。相比之下，MDG-ICP-MS的液滴传输效率为100%。sp-ICP-MS分析得到的颗粒数浓度低于预期（仅为预期值的20 - 40%），而MDG-ICP-MS的NP回收率高达80%。本研究表明，NP标准物质对于颗粒数测定至关重要，并讨论了不同悬浮液在储存时间方面颗粒数浓度的详细结果。
