Abstract View
Excitation Emission Matrix Fluorescence Spectroscopy for Analysis of Reactive Oxygen Species from Particulate Matter Samples
ISHRAT SINGH, Jiayang He, Michael Paulsen, Igor Novosselov, Christopher Simpson, University of Washington
Abstract Number: 551
Working Group: Carbonaceous Aerosol
Abstract
The presence of particulate matter (PM) in the environment can lead to adverse health impacts, like, cardiopulmonary diseases, neurological diseases, and lung cancer. While the epidemiological link between PM exposure and adverse health effects is clear, there is a lack of information regarding source-specific differences in PM toxicity. Thus, there is a clear need to quantify PM present in the environment and identify its sources and toxicity. Sources of combustion generated PM range from wildfires, residential wood burning, traffic emission, etc. Flame temperatures have been linked to changes in particle composition and hence the toxicity. Also, the capacity of combustion-generated PM to produce reactive oxygen species (ROS) has been proposed as one surrogate metric for the toxicity of PM. Currently, analysis of the composition of the organic fraction of PM is done using mass spectrometry (MS) methods, which are expensive and time-consuming. Excitation emission matrix (EEM) spectroscopy has been proposed as a low-cost, reliable method for analysis of the organic fraction of PM and for source apportionment. In this study, we investigate the correlation between EEM signature and ROS measurements. PM collected from laboratory flame, cookstove, and wildfire smoke are analyzed by EEM, GC-MS, and the dithiothreitol (DTT) assay for ROS. Using principal component regression (PCR) analysis of the EEM spectra, we drew the correlation between the EEM spectra and the DTT measurements. The results suggest that the total fluorescence measurement from EEM spectra is correlated with ROS, suggesting that EEM can be an alternative method to evaluate the ROS level in combustion-generated aerosols.