Carl E. Hensman and Gary D. Rayson
ICP atomic absorption spectrometry (ICP-AAS) has been presented as a possible solution for the analysis of complex samples. Unfortunately, the performance of an earlier configuration was limited as to the elements that could be determined with favorable figures of merit. The present study was undertaken to ascertain those fundamental parameters responsible for these limitations. The central channel through the plasma using a torch with an enlarged sample introduction tube (6.25 mm id) was found to exhibit lower Ar and Fe excitation temperatures than predicted. The presence of water vapor was also determined to have a significant impact on analytical signals from within the central channel-viewing region. The production of atomic species for detection by absorption was found to be strongly influenced by both analyte molecular bond strengths and the first ionization potential.