Mass Spectrometry of Airborne Nanoparticles

特拉华大学的Murray Johnston教授在化学系的分析和表面化学项目以及大气科学系的大气化学项目的支持下，开发了一种用于气溶胶质谱的纳米颗粒入口，并将其用于实验室和实地研究中空气中纳米颗粒的表征。目前，从环境空气中在线采样纳米颗粒到质谱仪的真空中是低效的，这给研究纳米颗粒的形成和反应性带来了困难。在这项工作中开发的入口将旨在传输大尺寸范围内的纳米颗粒，特别是小于10纳米的颗粒，以便确定它们的组成。这种分析方法将用于研究沿海海洋环境中纳米颗粒的形成和生长，以及研究二次有机气溶胶的形成。该项目将提供关于纳米粒子在环境中的来源和归宿的重要信息，以便评估它们对人类健康和环境的影响。该方法与人类在工作场所暴露于纳米粒子的研究以及生物系统中大分子和大分子组装体的研究有关。研究生和本科生将在这个涉及化学和大气科学的跨学科领域接受教育。实地测量的结果将被用作特拉华大学环境化学课程的案例研究，公众将参与大学赞助的科学推广活动。

Professor Murray Johnston of the University of Delaware is supported by the Analytical and Surface Chemistry Program in the Division of Chemistry and by the Atmospheric Chemistry Program in the Division of Atmospheric Sciences to develop a nanoparticle inlet for use with aerosol mass spectrometry, and to use it for characterization of airborne nanoparticles in laboratory and field studies. At present, on-line sampling of nanoparticles from ambient air into the vacuum of a mass spectrometer is inefficient, making it difficult to study nanoparticle formation and reactivity. The inlet being developed in this work will aim to transmit nanoparticles over a broad size range, especially particles smaller than 10 nm, so that their composition can be determined. This analytical methodology will be used to study the formation and growth of nanoparticles in a coastal marine environment, and to study the formation of secondary organic aerosols. The project will provide important information on the source and fate of nanoparticles in the environment so that their impacts on human health and the environment can be assessed. The methodology is relevant to the study of human exposure to nanoparticles in the workplace and to the study of large molecules and macromolecular assemblies in biological systems. A diverse group of graduate and undergraduate students will be educated in this interdisciplinary area involving chemistry and atmospheric science. The results of field measurements will be used as case studies for environmental chemistry coursework at the University of Delaware, and the general public will be engaged at University sponsored science outreach events.