METHODOLOGICAL PROBLEMS

The objective of quantitative spectral analysis is to establish a relationship between line intensity and concentration of an element in a mixture. Existing analytical procedures are based for the most part on determination of the relative intensities of the lines of the element being analyzed and those of a comparison (reference) element [25, 315] . The comparison standard is either the principal constituent of the mixture or an element added for this purpose. Two cases should be distinguished: when the ionization potential of the admixture (or minor constituent) to be determined is greater than that of the principal component, and vice versa. Let the principal component be denoted by A , the minor one by B, and their ionization potentials by VA and VB, respectively. Consider the first case: VB> VA. If the concentration of Β is low, its changes will not affect the discharge conditions. Consequently, f(Te) = const and ne = const. Then from relationship