Development of a Microfluidic Paper Analytical Device (uPAD) for Airborne Metals

描述（由申请人提供）：本研究的主要目的是开发新技术来表征工作场所空气中金属的个人暴露。第二个目标是提高空气中金属暴露评估的灵敏度和时间分辨率。这项工作的关键是一种名为微流控纸分析装置（5pad）的创新技术，它以低成本、高灵敏度的形式将采样与分析结合在一起。我们的中心假设是，5pad可以集成到个人气溶胶采样器中，用于量化个人暴露于空气中金属的采样和分析时间不到一小时。为了验证这一假设，我们提出了以下具体目标：(1)构建一个用于金属分析的单分析物微流控纸分析装置（5PAD），该装置与现有的尺寸选择性个人气溶胶采样器兼容；(2)构建多分析物5PAD分析空气中Pb、Cu、Mn、Ni的浓度；(3)现场验证多分析物5PAD的性能。成功完成上述目标将为工业卫生学家提供一种敏感的原位技术，以评估工作场所空气中的金属危害。这种技术代表了接触评估领域的一种范式转变，因为它有可能取代样品运输和实验室分析的传统做法（这两种做法都是时间和资源密集型的），采用灵敏度和时间分辨率更高的直接现场分析技术。本研究通过开发一种新的廉价仪器（跨部门主题）来评估工人暴露于空气中金属（影响运输/公用事业、制造业和建筑业）（跨部门主题），为国家职业研究议程（NORA）做出了贡献。与传统的ICP-MS或AES技术相比，5PAD样品的化学分析预计至少要便宜一个数量级（每个样品约5美元）。此外，将5PAD整合到现有的气溶胶取样装置（即可吸入过滤器取样器）将提高执业职业卫生专业人员对其的接受程度。这项技术可能为气溶胶暴露评估的新领域打开大门，因为5pad可以用于检测和量化许多金属、有机或无机化合物。

DESCRIPTION (provided by applicant): The primary objective of this research is to develop new technology to characterize personal exposure to airborne metals in the workplace. The secondary objective is to improve upon the state-of-the-art in both sensitivity and time-resolution of airborne metals exposure assessment. Key to this effort is an innovative technology called microfluidic paper analytical devices (5PADs) that integrate sampling with analysis in a low cost, high sensitivity format. Our central hypothesis is that 5PADs can be integrated into personal aerosol samplers for quantification of personal exposure to airborne metals with sampling and analysis times of less than one hour. To test this hypothesis, we propose the following specific aims: (1) Construct a single-analyte microfluidic paper analytical device (5PAD) for metal analysis that is compatible with existing, size-selective personal aerosol samplers; (2) Construct a multi-analyte 5PAD for analysis of Pb, Cu, Mn, and Ni concentrations in air; (3) Validate the performance of the multi-analyte 5PAD in the field. Successful completion of the above aims will provide industrial hygienists with a sensitive, in-situ technique to assess airborne metal hazards in the workplace. Such technology represents a paradigm shift in the field of exposure assessment, as it has the potential to replace the traditional practice of sample shipment and laboratory analysis (both of which are time and resource intensive) with a direct, field analysis technique with improved sensitivity and time-resolution. This research contributes to the National Occupational Research Agenda (NORA) by developing a new and inexpensive instrumentation (a cross-sector theme) for assessing worker exposure (a cross-sector theme) to airborne metals (affecting the transportation/utilities, manufacturing, and construction sectors). Chemical analysis of a 5PAD sample is expected to be at least an order of magnitude less expensive (around 5$ per sample) than analysis with traditional ICP-MS or AES techniques. Furthermore, integrating the 5PAD into existing aerosol sampling devices (i.e., inhalable filter samplers) will enhance its acceptance by practicing occupational health professionals. This technology may open the door to a new realm of aerosol exposure assessment, as 5PADs can be adapted to detect and quantify many metal, organic, or inorganic compounds. PUBLIC HEALTH RELEVANCE: The primary purpose of exposure assessment is to identify and prevent workplace conditions likely to cause injury and disease. Exposure assessment methods rely on the ability to make quantitative measurements of health hazards with little or no uncertainty, an assumption that is lacking for many emerging respiratory hazards in the workplace (e.g., beryllium, cadmium, and engineered nanoparticles). The sampling technology proposed here (5PAD) will help reduce this uncertainty by providing industrial hygienists with detection limits low enough to make informed decisions on protecting worker health and by aiding occupational epidemiologists in the detection of respiratory diseases without a proportionate increase in exposure assessment costs.