Criterion for determining the analytical emission lines in glow discharge optical emission spectrometry

Two major factors for selecting analytical lines, the sensitivity and the self-absorption effect, were compared between atomic lines and singly-ionized lines of copper as well as vanadium in glow discharge optical emission spectrometry. They have intense ionic lines which are excited through resonance charge-transfer collisions. It was found that the ionic lines are more sensitive compared to the atomic resonance lines; in addition, the ionic lines are essentially free from self-absorption, while the atomic lines suffer from self-absorption to a certain extent. The Cu II 224.70 nm, V II 309.31 nm, and V II 266.32 nm lines in the argon plasma, and the Cu II 270.32 nm line in the neon plasma are recommended as analytical lines of these elements.