Real-time monitoring of the surface and total composition of aerosol particles

Peter G. Carson, Murray V. Johnston, Anthony S. Wexler

Research output: Contribution to journalArticle

55 Citations (Scopus)

Abstract

Laser desorption ionization is used to characterize the products of an aerosol reaction in real time. Sodium chloride aerosols are mixed with vapor phase ammonia and nitric acid to produce an ammonium nitrate surface layer. The product aerosols are sampled directly into a mass spectrometer where the surface and total compositions are distinguished by laser desorption ionization. With a low laser irradiance, only material near the particle surface is desorbed and ionized. In this case, the mass spectra are independent of the amount of ammonium nitrate deposited, and simply indicate a nitrate-enriched surface layer. With a higher laser irradiance, both the surface layer and core are ablated. The relative intensities of ions originating from the surface layer and core reflect the total composition. That is, the relative intensities of ions produced from the ammonium nitrate surface layer increase with increasing surface layer thickness. The laser irradiance dependences of the mass spectra allow the surface and total composition to be qualitatively distinguished, but particle-to-particle variations of the relative signal intensities preclude a quantitative measurement of the amount of ammonium nitrate deposited.

Original languageEnglish (US)
Pages (from-to)291-300
Number of pages10
JournalAerosol Science and Technology
Volume26
Issue number4
StatePublished - Apr 1997
Externally publishedYes

Fingerprint

Aerosols
Particles (particulate matter)
surface layer
ammonium nitrate
aerosol
laser
Monitoring
monitoring
Chemical analysis
Nitrates
irradiance
Lasers
desorption
ionization
Ionization
ion
Desorption
sodium chloride
nitric acid
Ions

ASJC Scopus subject areas

  • Mechanical Engineering
  • Environmental Science(all)
  • Environmental Chemistry

Cite this

Carson, P. G., Johnston, M. V., & Wexler, A. S. (1997). Real-time monitoring of the surface and total composition of aerosol particles. Aerosol Science and Technology, 26(4), 291-300.

Real-time monitoring of the surface and total composition of aerosol particles. / Carson, Peter G.; Johnston, Murray V.; Wexler, Anthony S.

In: Aerosol Science and Technology, Vol. 26, No. 4, 04.1997, p. 291-300.

Research output: Contribution to journalArticle

Carson, PG, Johnston, MV & Wexler, AS 1997, 'Real-time monitoring of the surface and total composition of aerosol particles', Aerosol Science and Technology, vol. 26, no. 4, pp. 291-300.
Carson, Peter G. ; Johnston, Murray V. ; Wexler, Anthony S. / Real-time monitoring of the surface and total composition of aerosol particles. In: Aerosol Science and Technology. 1997 ; Vol. 26, No. 4. pp. 291-300.
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