Instrumentation for Semi-Continuous Fine Particulate Mass and Its Components

Brigham Young University, Provo UT

Investigators

Abstract

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.