AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Development of Aerosol Mass Spectrometer (AMS) with Two Switchable Ionization Methods for Characterization of Refractory and Non-refractory Components in Particles
HEE-JOO CHO, Heesung Kwak, Kihong Park, Gwangju Institute of Science and Technology
Abstract Number: 712 Working Group: Instrumentation and Methods
Abstract Aerosol mass spectrometer (AMS) has been used as a powerful tool for real-time measurement of chemical constituents of atmospheric aerosols. Various types of AMS have been developed. In particular, the Aerodyne AMS (Aerodyne Research Inc., USA) determines the chemical composition (organics, sulfate, nitrate, ammonium, and chloride) of particles by using a particle vaporization and electron impact (EI) ionization method, in which the non-refractory particles are vaporized at 600 °C under high vacuum and the generated vapors are immediately ionized via electron impact with the subsequent ion analyses by a quadruple or time-of-flight mass spectrometer. We are developing AMS with two convertible modes (laser desorption ionization (LDI) and thermal desorption-electron impact ionization (TD-EI)) equipped with a time-of-flight mass spectrometer. By utilizing LDI and TD-EI with a switchable mode, refractory and non-refractory species in submicrometer particles can be determined. The LDI allows us to measure refractory components such as black carbon, mineral dust, and heavy metals, while the TD-EI provides more quantification of non-refractory species (especially organic species). In this research, the AMS with the LDI and TD-EI is constructed and is being evaluated using various laboratory-generated particles.