Aerosol and Clouds
A comparison of particle mass spectrometers during the 1999 Atlanta Supersite Project
Article first published online: 10 APR 2003
Copyright 2003 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 108, Issue D7, 16 April 2003
How to Cite
2003), A comparison of particle mass spectrometers during the 1999 Atlanta Supersite Project, J. Geophys. Res., 108, 8424, doi:10.1029/2001JD000660, D7., et al. (
- Issue published online: 10 APR 2003
- Article first published online: 10 APR 2003
- Manuscript Accepted: 5 FEB 2002
- Manuscript Revised: 31 JAN 2002
- Manuscript Received: 23 MAR 2001
- mass spectrometer;
- single particle composition
 During the Atlanta Supersite Project, four particle mass spectrometers were operated together for the first time: NOAA's Particle Analysis by Laser Mass Spectrometer (PALMS), University of California at Riverside's Aerosol Time-of-Flight Mass Spectrometer (ATOFMS), University of Delaware's Rapid Single-Particle Mass Spectrometer II (RSMS-II), and Aerodyne's Aerosol Mass Spectrometer (AMS). Although these mass spectrometers are generally classified as similar instruments, they clearly have different characteristics due to their unique designs. One primary difference is related to the volatilization/ionization method: PALMS, ATOFMS, and RSMS-II utilize laser desorption/ionization, whereas particles in the AMS instrument are volatilized by impaction onto a heated surface with the resulting components ionized by electron impact. Thus mass spectral data from the AMS are representative of the ensemble of particles sampled, and those from the laser-based instruments are representative of individual particles. In addition, the AMS instrument cannot analyze refractory material such as soot, sodium chloride, and crustal elements, and some sulfate or water-rich particles may not always be analyzed with every laser-based instrument. A main difference among the laser-based mass spectrometers is that the RSMS-II instrument can obtain size-resolved single particle composition information for particles with aerodynamic diameters as small as 15 nm. The minimum sizes analyzed by ATOFMS and PALMS are 0.2 and about 0.35 μm, respectively, in aerodynamic diameter. Furthermore, PALMS, ATOFMS, and RSMS-II use different laser ionization conditions. Despite these differences the laser-based instruments found similar individual particle classifications, and their relative fractions among comparable sized particles from Atlanta were broadly consistent. Finally, the AMS measurements of the nitrate/sulfate mole ratio were highly correlated with composite measurements (r2 = 0.93). In contrast, the PALMS nitrate/sulfate ion ratios were only moderately correlated (r2 ∼ 0.7).