The effect of varying amounts of extraneous element upon the line intensity of different elements has been investigated. Slavin’s total energy method was used to make possible a more direct correlation than has been achieved using the internal standard method. The results of this study indicate that the effect of the extraneous element varies with the amount of extraneous element, but not in a simple linear fashion. The effect of an extraneous element on a group of lines of an element ending at the same energy level or beginning at the same energy level, is the same.
The experimental results show that the elements can be arranged in a series bases on their interelement effects in the d.c. arc. An arrangement of the elements in a series based on their boiling points and excitation potentials is in agreement with that found experimentally.
WALLACE R. BRODE and DONALD L. TIMMA, "The Influence of Extraneous Elements on Line Intensity. IV. Extraneous Element Effects in the Direct-Current Arc," J. Opt. Soc. Am. 39, 478-479 (1949)