Direct detection of silver nano particles in biological and environmental samples

纳米技术在研究和工业上仍然是一个新兴的领域，到目前为止，数百种不同的消费产品都使用了纳米材料。大约五分之一的消费产品含有纳米银。银纳米颗粒经常被添加到化妆品、卫生和保健产品以及食品和食品接触材料中。它们的广泛应用需要对银进行新的评估，即纳米银对人类健康和环境的风险。但是，官方机构无法根据现有的数据给出明确的意见。为此，必须获得更多的数据，并研究大量的样本序列。在这种背景下，迫切需要可靠和稳健的纳米颗粒检测分析方法，特别是在复杂样品基质和大样品系列中。此外，从2014年12月起，欧盟将强制要求食品中的纳米材料贴标签。因此，控制这一义务将需要适当的分析方法。目前有几种方法是研究的对象，并在本建议的最新情况中进行了详细讨论。在计划中的项目中，将开发一种新方法，允许快速和经济有效地筛选大量样品系列，以确定银纳米颗粒的存在。特别是，开发的方法将能够直接和选择性地检测固体复杂基质中的银纳米颗粒，而无需详细的样品制备。这将通过应用直接固体取样高分辨率连续源石墨炉原子吸收光谱法来实现。在初步实验中，我们可以证明，雾化延迟和雾化速率是银纳米粒子存在的重要指标。在计划的项目中，将进一步研究这种方法，以开发一种新的方法来检测和区分相关固体和复杂液体样品中的银纳米粒子和银离子。这种方法的优点是显而易见的：分析过程缩短，因为样品制备减少到样品均质化。从基质中提取或分离纳米颗粒是不必要的。因此，实现了更高的样品吞吐量，不需要试剂，也不会发生化学废物的处理。这使得该方法经济和生态效益（绿色分析化学；可持续性）。此外，在分析过程中，没有对原始样品进行任何操作，从而最大限度地减少了纳米颗粒的不期望转化。

Nanotechnology is still an emerging area in research and industry and so far several hundreds of different consumer products include nanomaterials. About a fifth of all consumer products comprise silver nanoparticles. Silver nanoparticles are often added to cosmetics, hygiene, and health care products as well as in food and food contact materials. Their broad application requires a new assessment of silver, i.e. silver nanoparticle risk to human health and environment. However, official bodies are unable to give a definite opinion on basis of the currently available data. For this purpose more data has to be gained and large sample series are to be studied. In this context, there is an urgent need for reliable and robust analytical methods for nanoparticle detection, especially in complex sample matrices and large sample series. In addition, from December 2014 on, labelling of nanomaterials in food will be mandatory in the EU. Hence, controlling this obligation will require suitable analytical methods. Several approaches are currently objects of research and are discussed in detail in the state-of-the-art of the present proposal. In the planed project, a new method will be developed, allowing fast and cost-effective screening of large sample series for the presence of silver nanoparticles. In particular the developed method will be able to detect directly and selectively silver nanoparticles in solid complex matrices without elaborative sample preparation. This will be achieved by application of direct solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry. In preliminary experiments we could show that atomisation delay and atomisation rate are significant indicators for the presence of silver nanoparticles. In the planed project this approach will be further pursued in order to develop a new method for detection and distinction of silver nanoparticles and silver ions in relevant solid and complex liquid samples. The advantages of such an approach are obvious: The analytical process is shortened, because sample preparation is minimised to sample homogenisation. Extraction or separation of nanoparticles from the matrix is unnecessary. Hence, a higher samples throughput is achieved, no reagents are required and no chemical wastes for disposal occur. This makes the method economical and ecological beneficial (green analytical chemistry; sustainability). Moreover, no manipulation of the original samples occurs which minimises undesired transformation of the nanoparticles in the course of the analytical procedure.