AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Comparing Two Laser Ablation Time-of-Flight Aerosol Mass Spectrometers
SOEREN ZORN, Klaus-Peter Hinz, Tabitha Schwinger, Philip Croteau, Alois Fendt, Bernhard Spengler, Douglas Worsnop, John Jayne, Achim Trimborn, AeroMegt GmbH
Abstract Number: 688 Working Group: Instrumentation and Methods
Abstract Mass spectrometry has become a very powerful tool for the analysis of the atmospheric aerosol. Modern on-line instruments offer not only a very high time resolution with sampling intervals down to seconds and essentially real-time analysis of the chemical and physical parameters of aerosol particles but can also be deployed with little effort at very remote locations.
Currently two types of aerosol mass spectrometers either based on thermal desorption electron ionization or laser desorption ionization are commonly used.
Most aerosol mass spectrometers using thermal desorption electron ionization are based on a common instrument platform and because of this, results from these instruments can generally be easily compared.
For laser ablation instruments the situation is more complex. Many such instruments are individual builds. Besides the differences in construction the lasers used for the ablation of particles in the individual instruments differ in wavelength as well as in pulse energy. This makes a comparison of results from various laser desorption ionization instruments more difficult. Here we present a comparison of two laser ablation instruments. A newly developed, very compact single particle mass spectrometer (LAAPTOF; AeroMegt GmbH) that is commercially available is compared to a custom built system (LAMPAS 3, University of Gießen). For the comparison of the two instruments we used a test set of aerosols comprised of several different chemicals. All test aerosols were dried prior to sampling. Additionally, spectra for each chemical makeup were recorded at different pulse energies for the ablation laser, to investigation the variability as well as the wavelength and energy dependence of the resulting ions and spectra.
The results allow not only a direct comparison of both instruments for the tested compounds but can be also applied to field measurements as well as show the best instrument configuration for intercomparison.