Single-particle characterization of summertime Antarctic aerosols collected at King George Island using quantitative energy-dispersive electron probe X-ray microanalysis and attenuated total reflection Fourier transform-infrared imaging techniques

Environ Sci Technol. 2011 Aug 1;45(15):6275-82. doi: 10.1021/es200936m. Epub 2011 Jul 8.

Abstract

Single-particle characterization of Antarctic aerosols was performed to investigate the impact of marine biogenic sulfur species on the chemical compositions of sea-salt aerosols in the polar atmosphere. Quantitative energy-dispersive electron probe X-ray microanalysis was used to characterize 2900 individual particles in 10 sets of aerosol samples collected between March 12 and 16, 2009 at King Sejong Station, a Korean scientific research station located at King George Island in the Antarctic. Two size modes of particles, i.e., PM(2.5-10) and PM(1.0-2.5), were analyzed, and four types of particles were identified, with sulfur-containing sea-salt particles being the most abundant, followed by genuine sea-salt particles without sulfur species, iron-containing particles, and other species including CaCO(3)/CaMg(CO(3))(2), organic carbon, and aluminosilicates. When a sulfur-containing sea-salt particle showed an atomic concentration ratio of sulfur to sodium of >0.083 (seawater ratio), it is regarded as containing nonsea-salt sulfate (nss-SO(4)(2-)) and/or methanesulfonate (CH(3)SO(3)(-)), which was supported by attenuated total reflection Fourier transform-infrared imaging measurements. These internal mixture particles of sea-salt/CH(3)SO(3)(-)/SO(4)(2-) were very frequently encountered. As nitrate-containing particles were not encountered, and the air-masses for all of the samples originated from the Pacific Ocean (based on 5-day backward trajectories), the oxidation of dimethylsulfide (DMS) emitted from phytoplanktons in the ocean is most likely to be responsible for the formation of the mixed sea-salt/CH(3)SO(3)(-)/SO(4)(2-) particles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerosols / analysis*
  • Antarctic Regions
  • Electron Probe Microanalysis / methods*
  • Geography*
  • Iron / chemistry
  • Particle Size
  • Particulate Matter / chemistry
  • Reference Standards
  • Seasons*
  • Spectroscopy, Fourier Transform Infrared
  • Sulfates / chemistry
  • Sulfites / chemistry
  • Sulfur / analysis
  • Time Factors

Substances

  • Aerosols
  • Particulate Matter
  • Sulfates
  • Sulfites
  • Sulfur
  • Iron