Selection of self-absorption free analytical lines of aluminum in glow discharge optical emission spectrometry

To obtain a larger dynamic range in the glow discharge emission spectrometric determination of aluminum, the use of the ionic lines instead of the atomic resonance line was suggested. The ionic lines are essentially free from self-absorption leading to better linearity of analytical curves, while the atomic lines suffer from self-absorption to a certain extent. The ionic lines of aluminum are hardly emitted by the argon plasma; however, they can be excited by the neon-argon as well as the argon-helium mixed gas plasma. Therefore, the mixed plasma gases should be used. Calibration curves were measured for the different plasma gases and the concentration interval over which they were linear was estimated.