Instrumentation for Semi-Continuous Fine Particulate Mass and Its Components

大气颗粒物有可能影响能见度、辐射平衡和健康。该项目将开发仪器，以确定直径小于2.5微米的环境大气颗粒物的特性，特别是半挥发性和含碳成分。将开发和验证两种仪器，它们将在项目结束时进行初步的当地现场测试。这些仪器包括一种改良的、市售的光学仪器，该仪器基于用光度计去除气相物质、过滤颗粒并在过滤器热解吸后进行测量，以及一种基于气相色谱/离子阱质谱法的纤维膜取样的物质定量。颗粒物的有机碳和元素碳组分将使用前一种仪器以1小时的时间分辨率进行测定（比通常采用的12至24小时分辨率测量有所改进），而特定排放源的标记有机化合物将使用后一种仪器进行量化。该项目将包括使用受控室来识别标记化合物并验证仪器的性能。该项目的更广泛影响包括可供感兴趣的社区成员使用的用于大气化学研究的新仪器。将有一个博士后研究员和几个研究生和本科生参与其执行。通过更好地量化颗粒物质的有机含量，特别是通过测量特定化合物，就可以就缓解措施作出更好的政策决定，并有可能对引起社会关注的颗粒物质的影响进行更定量的评估。

Atmospheric particulate matter has the potential to impact visibility, radiative balance, and health. This project will develop instruments to qualify the character of ambient atmospheric particulate matter with diameters less than 2.5 micrometers, particularly semi-volatile and carbonaceous components. Two instruments will be developed and validated, and they will be subject to a preliminary, local field test near the end of the project. The instruments include a modified, commercially-available, optical instrument based on removal of gas-phase species with a denuder, filtration of particulates and measurement following thermal desorption from the filter, and one based on fiber membrane sampling with gas chromatography/ion-trap mass spectrometry species quantification. The organic and elemental carbon fractions of particulate matter will be determined using the former instrument with 1-hour time resolution (an improvement over the commonly employed 12- to 24-hour resolution measurements), while marker organic compounds for specific emission sources will be quantified with the latter instrument. The project will involve the use of a controlled chamber to identify the marker compounds and to validate the performance of the instruments.Broader impacts of this project include new instrumentation for atmospheric chemistry research available for use by interested members of the community. There will be significant involvement of a post-doctoral fellow, and several graduate and undergraduate students in its execution. Through better quantification of the organic content of particulate matter, particularly through measurement of specific compounds, better policy decisions regarding mitigation measures can be made, and more quantitative assessment of impacts of particulate matter of societal concern is possible.