A Miniature Monitor for Time-Resolved Airborne Particle Chemistry

描述(申请人提供)：我们的母项目旨在开发一种小型、轻便、电池供电的收集器，适用于对空气中颗粒物的化学成分进行时间分辨的个人和微环境监测。这份修订意见书旨在通过开发一种对超细和纳米颗粒以及细颗粒有效的空气对空气颗粒浓缩器来加强这项技术。该浓缩器可以作为母项目下正在开发的微型颗粒收集器的合适入口；这也将适用于许多其他曝光、毒理学和超细颗粒表征应用。该方法利用了我们的专利水冷凝技术，其中小至0.003 5m的颗粒可以被包裹在3-5m的水滴中，形成差异扩散的层流。一旦扩大，液滴就会通过尖端小孔内汇聚的气流在空气动力学上进行聚焦。由于液滴的停留时间很短，化学伪影被减少到最小。使用这种方法，我们预计小至0.008 5米的颗粒的聚焦和10倍的空气对空气浓度。 公共卫生相关性：超细和细颗粒物在我们的环境中无处不在，但流行病学研究表明，它们的浓度与发病率和死亡率之间存在统计上的显著关系。超细颗粒被明确地牵连其中。建议开发一种仪器来浓缩空气中的超细颗粒物和细颗粒物，这将有助于评估它们的毒性和我们呼吸的空气中的颗粒物水平。

DESCRIPTION (provided by applicant): Our parent project aims to develop a small, lightweight, battery-powered collector suitable for time-resolved personal and micro-environmental monitoring of the chemical constituents of airborne particles. This revision submission aims to enhance that technology through the development of an air-to-air particle concentrator that is effective for ultrafine and nanometer-sized particles as well as fine particles. This concentrator can serve as a suitable inlet for the miniature particle collector being developed under the parent project; and that will also be suitable for many other exposure, toxicology and ultrafine particle characterization applications. The approach utilizes our patented water condensation technology, wherein particles as small as 0.003 5m can be encapsulated in a 3-5m water droplet in a differentially- diffusive, laminar flow. Once enlarged the droplets are aerodynamically focused through converging flow in a sharp-edged orifice. Because residence times of the droplets are short, chemical artifacts are minimized. With this approach we anticipate the focusing and 10-fold air-to-air concentration of particles as small as 0.008 5m. PUBLIC HEALTH RELEVANCE: Ultrafine and fine particles are ubiquitous in our environment, yet epidemiological studies have shown statistically significant relationships between their concentrations and rates of morbidity and mortality. Ultrafine particles are specifically implicated. Proposed is the development of an instrument to concentrate ultrafine and fine airborne particles that will aid in the assessment their toxicity and their levels in the air we breathe.