AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Feasibility of the Detection of Trace Elements in Particulate Matter Using Online High Resolution Aerosol Mass Spectrometry
DARA SALCEDO, Alexander Laskin, Vaithiyalingam Shutthanandan, Jose-Luis Jimenez, Universidad Nacional Autónoma de México
Abstract Number: 687 Working Group: Aerosol Chemistry
Abstract The feasibility of using an online thermal-desorption electron-ionization high-resolution aerosol mass spectrometer (HR-AMS) for the detection of particulate trace elements was investigated analyzing data from Mexico City obtained during the MILAGRO 2006 field campaign. Having the ability to detect and quantify airborne trace elements with much higher time resolution than is currently achievable with more conventional techniques (such as PIXE, XRF and ICP) is important to studies related to aerosol sources and health effects. The widespread availability and use of the HR-AMS, along with its high sensitivity and time resolution, makes this potential application of interest. High resolution mass spectral analysis, isotopic ratios, and ratios of different ions containing the same elements were used to constrain the chemical identity of the measured ions. The detection of Cu, Zn, As, Se, Sn, and Sb is reported. Concentration time series obtained from the AMS data were compared to concentration records determined from offline analysis of particle samples from the same times and locations by ICP (PM2.5) and PIXE (PM1.1 and PM0.3). The AMS shows promise for real-time detection of some trace elements, although additional work including laboratory calibrations with different chemical forms of these elements are needed to further develop this technique and to understand the differences with the ambient data from the other techniques.