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Continuous Mass Spectrometric Analysis of Environmental Pollutants Using Surface Ionization

  • William D. Davis
Part of the Environmental Science Research book series (ESRH, volume 13)

Abstract

An instrument for real-time analysis of trace impurities in air, including particulates was constructed and evaluated. The sampling system impinges a beam of particles and air on a heated Re ribbon and the resulting ions analyzed in a 7.6 cm radius magnetic sector mass spectrometer. Oxygen in the air raises the work function of the Re to about 7.2 eV at 1,000°K allowing analysis of elements and compounds with ionization potentials as high as 8 eV. For some low ionization potential elements, particles containing 1,000 atoms, particle concentrations of less than 1 per cm3 and average concentrations of 10-12–10-13 g/m3 can be detected. Organic compounds can have ionization efficiencies as high as 20% and can be detected in concentrations as low as 0.001 ppb. Water is analyzed by forming an aerosol. Alkali metals and other easily ionized metals can be detected at concentrations of 10-13 g/cm3 of water.

Keywords

Work Function Ionization Efficiency Surface Ionization Electron Bombardment Alkali Metal Salt 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

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Copyright information

© Plenum Press, New York 1978

Authors and Affiliations

  • William D. Davis
    • 1
  1. 1.Corporate Research and DevelopmentGeneral Electric CompanySchenectadyUSA

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