Abstract

The potential of near-infrared photothermal spectroscopy for the analysis of aerosols collected on filter membranes is demonstrated. Laboratory-generated aerosols consisting of ammonium sulfate and soot are collected on Teflon® filters by the use of a dichotomous sampler. The N-H overtone/combination band at 2110 nm is used to determine ammonium in these mixtures. The presence of soot is shown to have a deleterious effect on the detectability of ammonium. The extent of this limitation is examined with the employment of well-characterized samples. An empirical expression, based on Beer's law, is developed which relates the photothermal signal to the relative soot and ammonium sulfate loadings.

Photothermal aerosol absorption spectroscopy

Horn-Bond Lin and Anthony J. Campillo
Appl. Opt. 24(3) 422-433 (1985)

Optical properties of internally mixed ammonium sulfate and soot particles--a study of individual aerosol particles and ambient aerosol populations

Annette Worringen, Martin Ebert, Thomas Trautmann, Stephan Weinbruch, and Günter Helas
Appl. Opt. 47(21) 3835-3845 (2008)

Fourier transform infrared spectroscopy of size-segregated aerosol deposits on foil substrates

Judith A. Hopey, Kirk A. Fuller, Venkataramanan Krishnaswamy, David Bowdle, and Michael J. Newchurch
Appl. Opt. 47(13) 2266-2274 (2008)

Photoacoustic determination of optical properties of aerosol particles collected on filters: development of a method taking into account substrate reflectivity

R. Röhl, W. A. McClenny, and R. A. Palmer
Appl. Opt. 21(3) 375-381 (1982)

Composition measurement of aerosols of submicrometer particles by phase fluctuation absorption spectroscopy

David U. Fluckiger, Horn-Bond Lin, and William H. Marlow
Appl. Opt. 24(11) 1668-1681 (1985)