Detection of engineered nanomaterials in drinking water, food, commercial product

描述(申请人提供)：纳米技术正在迅速导致纳米材料(NMS)的生产，这些材料将用于从牙膏到杀虫剂的一切领域，但研究界缺乏足够的技术来测量纳米材料的大小和浓度，即使是最简单的环境和生物样本，其水平可能与人类接触有关。包括NIEHS在内的国家纳米技术倡议和其他组织将开发方法对饮用水、商业产品、血液和其他生物基质中的纳米材料进行量化的必要性列为首要任务。我们拟议工作的目的有两个：首先，我们的目标是为国际科学、医疗和监管机构开发最先进的纳米材料暴露评估工具；其次，我们将根据公布的毒理学数据确定并量化可能有害的暴露水平与使用当前技术的非标记商业纳米材料可以达到的方法检测限值之间的计量差距。无机和碳质纳米材料的合成具有广泛的尺寸、形状和各种表面涂层或功能。因此，人们可能很快就会在工作场所或其他日常活动中接触到数千种不同类型的纳米材料。由于缺乏足够的检测能力，这些暴露的风险评估受到阻碍。虽然电子显微镜和其他技术可以对样品中的NMS进行成像，但它们无法量化NMS的大小、数量浓度和质量浓度，而这些被认为是理解正确评估NM暴露和影响的关键。我们假设，两个基本的仪器平台(离子耦合等离子体质谱和液相色谱质谱)可以与样品前处理方法相结合，包括从环境和生物样品中提取、分离和/或浓缩NMS，以定量目前最广泛使用的无机NMS(银、二氧化钛、Au)和碳质NMS(富勒烯和官能化富勒烯)的尺寸、数量浓度和质量浓度。为了支持这一假设，我们将利用最初开发的技术来量化天然水生胶体(即NMS)和有机污染物。具体地说，实时单粒子电感耦合等离子体质谱(RTSP-MS)将用于区分金属或金属氧化物纳米材料与溶解的离子形式的基础纳米材料。碳质NMS将以与有机化学品类似的方式进行处理，方法是根据溶解性和疏水性特征对其进行前处理和分析(LC/MS)。通过与广泛使用的一系列NMS合作，这些方法将立即得到广泛应用。将制定NM分析技术和提取方案的标准操作程序。调查人员与NMS合作多年，熟悉NMS的采购、表征、溶解和处理。使用可靠的统计方法，将验证程序(检测下限、精密度、准确度、重复性、回收率等)。一旦得到验证，这些前处理方法和分析技术将用于对饮用水、食品、消费品和生物液体(包括全血、血浆、血清、尿液和母乳)中的工程纳米材料进行量化。我们的团队在分析这些基质中的人造污染物方面拥有丰富的经验。由于目前环境中对工程NMS的暴露很低，可能除了二氧化钛外，我们预计不会在我们存档的生物液体或饮用水样本中检测到这些类型的材料。在验证了这一假设之后，我们将分别用已知的和不断增加的不同工程NMS的浓度来加强等量的血液、母乳和尿液，直到检测成为可能。除了验证程序外，这项工作还将确定NMS(或缺乏NMS)在人类中的当前身体负担，并将有助于确定需要何种水平的这些材料才能利用最先进的技术实现对工程NMS的检测。开发的所有方案都将发表在同行评议的期刊上，并作为循序渐进的程序在互联网上免费提供，以使美国和国外的其他实验室和研究人员能够使用这些新的人类暴露评估工具。在我们的数据分析和解释中，我们将比较可实现的方法检测限值和毒性阈值信息，以评估使用这些新工具进行环境暴露评估和保护人类健康的前景。 公共卫生相关性：该项目将向新兴的纳米环境和健康影响社区提供有充分文件记录的分析技术和方法，用于量化基质(水、食品、生物液体)中工程纳米材料的尺寸、数量浓度和质量浓度。这些信息对于在体内或体外健康效应研究期间评估纳米材料的剂量和暴露至关重要。这项研究使此类研究能够在亚致命性暴露下进行，过去由于分析方法不充分，这在很大程度上是复杂的。

DESCRIPTION (provided by applicant): Nanotechnology is rapidly resulting in the production of nanomaterials (NMs) that will be used in everything from toothpaste to pesticides, yet the research community lacks adequate techniques to measure the size and concentration of nanomaterials in even the simplest of environmental and biological samples at levels which may be relevant to human exposures. The National Nanotechnology Initiative, including NIEHS, and other organizations ranks as a top priority the need to develop methods to quantify nanomaterials in matrices including drinking water, commercial products, blood and other biological matrices. The purpose of our proposed work is two-fold: first, we aim to develop state-of-the- art exposure assessment tools for nanomaterials for the international scientific, medical and regulatory community; second, we will identify and quantify the metrology gap between what exposure levels may be potentially harmful based on published toxicological data and the method detection limits that can be achieved for non-labeled commercial nanomaterials with current technology. Inorganic and carbonaceous nanomaterials are being synthesized in a wide range of sizes, shapes and with various surface coatings or functionalities. Consequently, people may soon be exposed to thousands of different types of nanomaterials in their workplace or during other daily activities. Risk assessments from these exposures are hampered by the lack of adequate detection capabilities. While electron microscopy and other techniques can image NMs in samples, they fall short of being able to quantify the size, number concentration and mass concentration of NMs which are thought to be crucial for understanding to properly assess NM exposures and effects. We hypothesize that two basic instrumentation platforms (ion coupled plasma mass spectroscopy and liquid chromatography mass spectroscopy) can be developed in conjunction with sample pretreatment methods, involving extraction, separation and or concentration of NMs from environmental and biological samples, to quantify the size, number concentration and mass concentration of the currently most widely used inorganic NMs (Ag, TiO2, Au) and carbonaceous NMs (fullerenes and functionalized fullerenes). To support this hypothesis we will exploit techniques initially developed to quantify natural aquatic colloids (i.e., NMs) and organic pollutants. Specifically, real time single particle ICP mass spectroscopy (RTSP-MS) will be used to differentiate metal or metal oxide NMs from dissolved ionic forms of the base NM material. Carbonaceous NMs will be handled in a similar fashion as organic chemicals, by pre-treating and analyzing (LC/MS) them based upon solubility and hydrophobicity characteristics. By working with a range of widely employed NMs the methods will be immediately and widely applicable. Standard operating procedures for NM analytical techniques and extraction protocols will be developed. The investigators have been working with NMs for many years, and are familiar with purchasing, characterizing, solubilizing and handling NMs. Using robust statistical approaches, the procedures (detection limits, precision, accuracy, reproducibility, recovery rate, etc) will be validated. Once validated, the pretreatment methods and analytical techniques will be used to quantify engineered nanomaterials in drinking water, food, consumer products and biological fluids (including whole blood, blood plasma, blood serum, urine and human milk). Our team has extensive experience in the analysis of manmade pollutants in these matrices. Due to a presumably low present ambient exposure to engineered NMs, except perhaps for TiO2, we do not expect to detect these types of materials in our archived samples of biological fluids or drinking waters. After testing this hypothesis, we will fortify aliquots of pools of blood, human milk and urine, respectively, with known and increasing concentrations of diverse engineered NMs, until detection becomes possible. In addition to validating the procedures, this work will establish the present body burden in humans of NMs (or lack thereof) and will help to define what levels of these materials are required in order to achieve detection of engineered NMs with state of the art techniques. All protocols developed will be published in peer- reviewed journals and made freely available on the Internet as step-by-step procedures to enable other laboratories and researchers in the U.S. and abroad to utilize these new human exposure assessment tools. In our data analysis and interpretation, we will compare achievable method detection limits with toxic threshold information to evaluate the prospects of using these novel tools for environmental exposure assessment and for protecting human health. PUBLIC HEALTH RELEVANCE: This project will provide to the emerging nano environmental and health effects community well documented analytical techniques and methodologies for quantifying the size, number concentration and mass concentration of engineered nanomaterials within matrices (water, food, biological fluids). This information is critical to assessing nanomaterial dosage and exposure during in vivo or in vitro health effects studies. The research enables such studies to be conducted at sub lethal exposures, which have largely been complicated in the past due to inadequate analytical methods.