Intensity Relations for Determining Gas-Phase OH, Cl, Br, I, and Free-Electron Concentrations by Quantitative ESR

The theoretical intensities for the absorption lines of gas phase OH and NO as observed with an ESR spectrometer are discussed. Since both species have transitions of the electric-dipole type, it is shown how the absolute concentration of OH may be determined by comparing its integrated intensity with that of the stable NO used as a reference gas. A similar procedure for determining the concentration of free electrons from their electric-dipole cyclotron resonance absorption signal is also outlined. Finally, the intensity relations useful for determining all of the halogen atoms (except fluorine) using O2 as the reference gas are derived.