Metal fingerprinting and chemothermal isolation methods to quantify natural and engineered carbon nanoparticles

CBET-1336794概述：PI寻求开发使用热分离技术和金属含量特征来量化、指纹和区分天然和工程碳纳米颗粒的方法。PI基于成熟的量化黑碳(BC)碳烟的热方法，提出了一种基于其不同的热稳定性来区分非纳米颗粒天然有机物、单壁碳纳米管(SWCNTs)和BC(最普遍的天然碳纳米颗粒)的技术。初步结果表明，天然有机物、碳纳米管和碳纳米管具有独特的氧化范围，可以通过顺序氧化结合元素分析来区分和定量。在这里，我们旨在证明，这些热稳定性在空气、水、沉积物和土壤的复杂混合物中保持不变，因此，可以用于定量描述环境基质中的纳米颗粒(例如，天然和工程)。此外，通过完全酸消化和质谱学测定的大宗金属含量应该为来源解析提供一条途径。这种方法的优点包括低成本、可获得性、高通量能力，以及这种方法所需的最少的样品处理(例如提取)，这减少了分析过程中分析物损失和转化的可能性。智力价值：美国国家研究委员会2012年EHS纳米技术研究战略报告将分析技术列为第一研究重点。目前测量工作场所(和大气)中含碳纳米颗粒(CNP)的方法主要依赖于光散射颗粒测量仪，它提供了纳米尺寸颗粒的体积测量。然而，随着合成方法形成工程碳纳米颗粒(即碳纳米管和石墨烯)的已知共同产生天然纳米颗粒(即烟尘)，目前的结果报告自然加工程纳米颗粒暴露。因此，不可能定量地确定职业暴露在工程纳米颗粒中。此外，还没有方法来评估向大气中释放的工程纳米颗粒，这可能是CNP向环境输送的一个载体。这对正在进行的纳米粒子研究产生了严重的后果：(1)命运模型缺乏有效的来源数据，(2)既不能评估也不能强制执行职业暴露，以及(3)在必要的情况下不能减轻环境释放。项目完成后，将首次可能对天然和工程碳纳米颗粒(NPs)进行定量区分，从而能够准确评估暴露于工程NPs的情况，与天然NPs相比，工程NPs具有独特的性质、形态和毒性。这些目标是在团队内实现的？S接触并依赖于负担得起的、可获得的技术。广泛的影响：私人投资机构及其研究小组积极参与由杜克大学纳米技术对环境的影响中心(CEINT)主办的外展工作，以及那里的其他科学丰富活动，包括女性在数学工程和科学方面表现更出色(女性)(100%女性来自代表性不足的群体)志愿科学研讨会。作为拟议工作的一部分，私人投资机构将建立一个纳米分析的K-12教育模块(CSI是真的吗？快速纳米取证？)，这将作为NanoDays、Femmes的一部分教授，然后分发给CEINT的K-12教育工作者网络。此外，该节目将针对更高级的受众(如公共图书馆和老年中心)进行修改，进行现场直播，并录制视频以供网络传播。

CBET - 1336794Overview:The PIs seek to develop methodology to quantify, fingerprint, and distinguish natural and engineeredcarbonaceous nanoparticles using thermal separation techniques and metal content signatures.Building on well-established thermal methods to quantify black carbon (BC) soot, the PIspropose a technique that distinguishes non-nanoparticulate natural organic matter, single-walledcarbon nanotubes (SWCNTs), and BC (the most ubiquitous, natural carbonaceous nanoparticle)based on their distinct thermal stabilities. Preliminary results suggest that natural organicmatter, SWCNTs, and BC have unique oxidation ranges and could be distinguished and quantifiedfollowing sequential oxidations coupled with elemental analysis. Here, we aim to demonstratethat these thermal stabilities are preserved in complex mixtures of air, water, sediments,and soil, and as a result, can be used to quantitatively delineate the nanoparticles (e.g.,natural vs. engineering) in environmental matrices. Furthermore, bulk metal contents determinedvia complete acid digestion and mass spectrometry should provide a route toward source apportionment.Advantages of this approach include the low cost, accessibility, high-throughput capabilities,and minimal sample processing (e.g., extraction) required for this method, which reduces thepotential for analyte loss and transformation during analysis.Intellectual Merit :The National Research Council 2012 EHS Nanotechnology Research Strategy report listed analyticaltechniques as the first research priority. Current approaches for measuring carbonaceousnanoparticles (CNPs) in the work place (and atmosphere) primarily rely on light-scatteringparticle sizers, which provide a bulk measure of nano-sized particles. However, as syntheticapproaches to form engineered carbonaceous nanoparticles (i.e, carbon nanotubes and graphene)are known to co-produce natural nanoparticles (i.e., soot), current results are reportingnatural plus engineered nanoparticle exposure. Thus, it is not possible to quantitativelydetermine occupational exposure to engineered nanoparticles. In addition, there are no methodsto assess release of engineered nanoparticles to the atmosphere, which is a likely vectorfor CNP transport to the environment. This has severe consequences for ongoing nanoparticleresearch: (1) fate models lack validated source data, (2) occupational exposure can be neitherassessed nor enforced, and (3) environmental release can not be mitigated where necessary.Upon project completion, quantitatively differentiation of natural and engineered carbonaceousnanoparticles (NPs) will be possible for the first time, allowing accurate assessment of exposureto engineered NPs, which have unique properties, morphologies, and toxicities compared tonatural NPs. These goals are within the team?s reach and rely on affordable, accessible technologies.Broader Impacts :The PIs and their research groups are actively involved in the outreach efforts hosted bythe Center for the Environmental Implications of Nano-technology (CEINT) at Duke University,as well as other science enrichment activities there, including Females Excelling More inMath Engineering and Science (FEMMES) (100% females from underrepresented groups) volunteerscience workshops. As part of the proposed work, the PIs will establish a nano-analyticalK-12 education module (Is CSI for real? Rapid Nano-forensics?), and this will be taught aspart of NanoDays, FEMMES, and later distributed to the CEINT network of K-12 educators. Additionally,the program will be modified for a more advanced audience (e.g., public library and seniorcenter), delivered live, and videotaped for web distribution.