EFFECT OF SELECTIVE LASER EXCITATION ON THE IONIZATION OF ATOMIC SPECIES IN FLAMES

Laser enhanced ionization of atomic species in flames, also known as the optogalvanic effect, has been used as the basis for a new spectrometric technique. A simple model Is formulated here to help explain the production of electron-ion pairs by the combination of optical and collisional processes. The model yields an analytical expression for the relative enhanced ionization sensitivity of a given transition of any element, and also predicts possible sources of bias in spectrometric applications. The theoretical function is fitted to experimental data by the least-squares adjustment of two parameters. The fitted function may be used, with appropriate caution, to predict the potential LEI sensitivity of further elements and transitions in a similar flame. The model should provide a durable foundation for the further development of methodology and instrumentation for atomic spectrometry by laser enhanced ionization in flames. © 1979, American Chemical Society. All rights reserved.