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

概述：pi寻求开发方法来量化，指纹，并使用热分离技术和金属含量特征区分天然和工程碳纳米颗粒。在已建立的量化黑碳（BC）烟灰的热方法的基础上，研究人员提出了一种基于其独特的热稳定性来区分非纳米颗粒天然有机物质、单壁碳纳米管（SWCNTs）和BC（最普遍的天然碳质纳米颗粒）的技术。初步结果表明，天然有机物、SWCNTs和BC具有独特的氧化范围，可以通过结合元素分析的顺序氧化来区分和定量。在这里，我们的目标是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，自然与工程）。此外，通过完全酸消化和质谱法测定的大量金属含量应该为来源分配提供一条途径。该方法的优点包括低成本，可及性，高通量能力，以及该方法所需的最小样品处理（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。智力优势：国家研究委员会2012 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）中碳纳米颗粒（CNPs）的方法主要依赖于光散射粒度仪，它提供了纳米颗粒的大量测量。然而，由于已知形成工程碳质纳米颗粒（即碳纳米管和石墨烯）的合成方法可以共同产生天然纳米颗粒（即烟灰），目前的结果是报告天然加工程纳米颗粒暴露。因此，不可能定量地确定职业性暴露于工程纳米颗粒。此外，目前还没有方法来评估工程纳米颗粒向大气中的释放，而大气可能是CNP向环境运输的载体。这对正在进行的纳米颗粒研究造成了严重的后果：(1)命运模型缺乏经过验证的源数据，(2)既不能评估也不能强制职业性暴露，(3)在必要时不能减轻环境释放。项目完成后，将首次有可能定量区分天然和工程碳纳米颗粒（NPs），从而准确评估工程NPs的暴露情况，与天然NPs相比，工程NPs具有独特的性质、形态和毒性。这些目标是团队内部的吗？我们依靠的是可负担的、可获得的技术。更广泛的影响：pi和他们的研究小组积极参与杜克大学纳米技术环境影响中心（CEINT）的推广工作，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更出色（FEMMES）（100%来自代表性不足群体的女性）志愿者科学研讨会。作为拟议工作的一部分，pi将建立一个纳米分析k -12教育模块(CSI是真的吗？快速纳米取证？)，这将作为纳米日，FEMMES的一部分教授，后来分发给K-12教育工作者的CEINT网络。此外，该计划将为更高级的观众（例如公共图书馆和老年人中心）进行修改，现场直播，并录制视频以供网络分发。

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.