Application of Mass Filter System to an Analysis of Trace Components in the Atmospheric Air

I. .Non-concentration Principle and the Detection Limit

Abstract

Applicability of the mass filter system to air pollution analysis was examined by introducing standard samples(1-10 ppm Kr or Xe in Ar gas)as well as the atmospheric air without passing the concentration process. Detection of the mass-analyzed ions was made by using an usual DC amplifier and pulse counting technique. Interference of other components and backgrounds to a mass peak was reduced by changing the acceleration energy of the bombarding electron beam. With this method, neon isotope Ne²² in the air(about 1.6ppm)could be measured by eliminating the contribution from CO₂⁺⁺. Measured isotope abundance ratios of 1ppm Kr and Xe in argon gases were found very close to the reference values of pure Kr and Xe gases. All tests have proved that the mass filter system has a sensitivity high enough for detecting the 1-0.1ppm components in the air with no help of the concentration process, and that the system is promising for the component analysis in the air pollution problems.