AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
The Development of Electrostatic Precipitation-Electrospray Ionization Mass Spectrometry (EP-ESI-MS) for Aerosol Analysis
SIQIN HE, Lin Li, Hongxu Duan, Amir Naqwi, Christopher Hogan Jr., University of Minnesota
Abstract Number: 83 Working Group: Instrumentation and Methods
Abstract Electrospray ionization (ESI) is a suitable mode of ion generation for mass analysis of many organic species for which alternative ionization techniques can lead appreciable analyte fragmentation. For this reason, ESI is an ideal method for the analysis of species within aerosol particles. However, low concentrations of aerosol particles in most environments has limited ESI application in aerosol particle analysis; aerosol mass spectrometers typically employ thermal or laser volatilization followed by electron ionization or chemical ionization, which can lead to a considerable degree of analyte fragmentation. In this presentation, the development of an approach to apply ESI to molecules within submicrometer and nanometer scale aerosol particles is discussed. This technique, which we term electrostatic precipitation-ESI-MS (EP-ESI-MS), utilizes unipolar ionization to charge particles, electrostatic precipitation to collect particles on the tip of a Tungsten rod, and subsequently, by flowing liquid over the rod, ESI and mass analysis of the species composing collected particles. EP-ESI-MS is shown to enable analysis of nanogram quantities of collected particles composed of cesium iodide, levoglucosan, and levoglucosan within a carbon nanoparticle matrix. With EP-ESI-MS, the integrated mass spectrometric signals are found to be a monotonic function of the mass concentration of analyte in the aerosol phase. We additionally show that EP-ESI-MS has a dynamic range of close to 5 orders of magnitude in mass, making it suitable for molecular analysis of aerosol particles in laboratory settings with upstream particle size classification, as well as analysis of PM 2.5 particles in ambient air.