Excitation mechanisms on emission lines observed with a glow discharge excitation source.

Emission lines from a Grimm-type glow discharge tube are compiled for copper, silver, aluminium, tin, lead and bismuth. Very intense lines, which are not listed as analytical lines in conventional emission spectrometric analyses, can be observed in a vacuum ultraviolet wavelength region. The emission intensities of the ionic lines principally depend on the kind of the plasma gas employed. Excitation mechanisms of these lines are discussed in the Ar, Ne and N2 plasmas or in the mixture plasmas with He. The line of excitation can be attributed to a (resonance) charge transfer reaction between analyte atoms and excited species of the plasma gas.