Selection of Optimum Analytical Lines for the Determination of Several Alloyed Elements in Steel Samples in Glow Discharge Optical Emission Spectrometry with Krypton and Argon

The most sensitive emission lines for determination of cobalt, nickel, and vanadium in steel samples were investigated when krypton was employed as an alternative plasma gas in glow discharge optical emission spectrometry. A thorough survey in the emission spectra indicated that more sensitive ionic lines of nickel as well as cobalt, which were free from spectral interference from iron, could be found when using krypton gas instead of argon gas; therefore, the krypton plasma was recommended in the determination of nickel and cobalt in iron-matrix alloy samples. However, the argon plasma yielded more intense ionic lines of vanadium suitable for the vanadium determination in iron-matrix alloy samples. These phenomena could be explained by resonance energy-transfer collisions with the plasma gases which selectively populate different excited levels of these ions between the krypton and the argon plasmas.