Composition of Individual Particles Segregated According to Electrical Mobility, Hygroscopicity, Volatility and Mass

将使用市售的气溶胶飞行时间质谱仪（ATOFMS）来测量已根据各种物理特性预先分类的颗粒的组成。这些测量将为了解大气颗粒物的物理/化学性质和混合特性提供新的见解。这些信息对于解释来自更传统的仪器的数据是有价值的，并且可以用于评估最先进的模型，这些模型描述了来自各种来源的气溶胶的演变作为大小和组成的函数。根据电迁移率（尺寸），使用微分迁移率分析仪（DMA）对颗粒进行分类，根据尺寸和吸湿性，使用串联微分迁移率分析仪（TDMA）进行分类，或根据尺寸，使用DMA或TDMA进行分类，并使用气溶胶颗粒质量分析仪（APM）进行质量分类。将通过加热按大小分类的颗粒，然后再用原子能飞行物质谱仪分析这些颗粒，研究挥发对颗粒成分的影响，该项目头两年将侧重于对已知成分的实验室气溶胶进行研究，并制定实地测量的取样程序。一个密集的实地活动将在佐治亚州亚特兰大进行。该项目代表了明尼苏达大学和卡尔顿学院之间的合作。

A commercially available Aerosol Time of Flight Mass Spectrometer (ATOFMS) will be used to measure the composition of particles that have been preclassified according to various physical properties. These measurements will provide new insights into the physical/chemical properties and mixing characteristics of atmospheric particles. Such information is valuable for interpreting data from more conventional instrumentation and can be used to evaluate state-of-the-art models that describe the evolution of aerosols from various sources as a function of size and composition. Particles will be classified according to electrical mobility (size) with a differential mobility analyzer (DMA), size and hygroscopicity with a tandem differential mobility analyzer (TDMA), or size with a DMA or TDMA and mass with an Aerosol Particle Mass Analyzer (APM). The effect of volatilization on composition will be studied by heating size-classified particles before analyzing them with the ATOFMS.The first two years of the project will focus on studies with laboratory aerosols of known composition and on the development of sampling protocols for field measurements. An intensive field campaign will be carried out in Atlanta, GA. This project represents a collaboration between the University of Minnesota and Carleton College.