Laser Mass Spectrometric Analysis of Organic Atmospheric Aerosols. 1. Characterization of Emission Sources

Abstract

Carbonaceous aerosol particles stemming from combustion processes play a key role in air pollution. Major emission sources include Diesel vehicles, gasoline vehicles, residential heating, wood fires, and cigarettes. The chemical characterization of the particles is essential to the identification of their origin. This task can be accomplished using two-step laser mass spectrometry (L2MS). Only small sample quantities are necessary, and the measurements can be performed within minutes. L2MS was found to be a valuable alternative to more laborious chemical analysis techniques that often require extensive sample preparation. Tracer mass spectral patterns were identified, notably based on specific polycyclic aromatic hydrocarbons (PAHs) and other polycyclic aromatic compounds (PACs). Their specificity allows the identification of different particle emission sources at sites of exposure.

Review of Recent Advances in Detection of Organic Markers in Fine Particulate Matter and Their Use for Source Apportionment

“…159 Matrix effects that can deleteriously affect quantitation are eliminated by liberating neutral species from the particles with the IR laser pulse in the first step. This approach was applied to different types of samples including ambient organic aerosols, 160,161 tobacco smoke, 162 and PAHs. 163 Moreover, quantitative detection and depth profiling of organic components in single particles have been demonstrated by single-photon ionization (SPI) with coherent vacuum ultraviolet (VUV) radiation.…”

Polycyclic aromatic hydrocarbons and amino acids in meteorites and ice samples from LaPaz Icefield, Antarctica

“…In order to achieve sufficient gas flow through the filters, the filter holder was connected to a rotary vacuum pump. The filter holder is described in detail by Haefliger et al (2000). The samples were collected under the following different engine performance levels:…”

Potential of laser mass spectrometry for the analysis of environmental dust particles—A review

“…For each of these particle types, a typical PAH pattern was obtained [117]. Tracers of diesel or gasoline vehicle exhaust aerosols have been clearly identified [121]. Their spatial and temporal repartitions have also be followed on a 24-h period of time [122].…”

“…Principal component analysis (PCA) [106,121,122] allowed markers of different pollution sources to be identified. Specific algorithms ART-2a and more recently PMF approaches have been developed for the treatment of data collected by on-line mass spectrometry, readers have to refer to corresponding previous sections for more detailed information and applications.…”

“…Consequently, the control of the laser-matter interaction was also limited. But it is possible to measure the laser pulse energy and to normalize the mass spectra with these values if this fluctuation of laser output energy did not drastically modify the nature of the laser-particle interaction [121]. Nevertheless, the last generation of Nd-YAG solid laser allowed to reduce this drawback, these lasers are nowadays more stable.…”