Influence of Chemically Active Additives on the Nature of the Evaporation of Highly Volatile Impurities during Their Determination in Aluminum and Its Oxide by Arc Atomic Emission Spectrometry

The effect of chemically active fluorine-containing additives AlF3, AgF, and ZnF2 on the nature of the evaporation of non-volatile elements, B, Be, Cr, Hf, Mo, Si, Ti, and V from aluminum oxide in a direct current arc is studied. It is found that, in the presence of these additives, the intensity of the spectral lines significantly increases and the time of complete evaporation from the electrode decreases for all elements under study, which indicates the formation of their highly volatile fluorides in the electrode crater. It is shown that zinc fluoride is the most effective additive among the studied compounds. This additive ensures the reduction of the limits of determination of highly volatile elements in aluminum oxide by one and a half to two orders of magnitude compared to the version without additives, and also the improvement of the convergence of determination results.