Spectrographic solution and salt-cap techniques are described for the determination of beryllium, lead, and other trace elements in magnesium alloys in the range 0.0001-0.3%. Beryllium is determined with a precision within ±4% between 0.0001 and 0.01% with a high voltage spark source and a rotating disk electrode method. Comparative sensitivity and precision results are given for Al, Ca, Cu, Fe, Mn, Pb, Ni, Sn, and Zn with a high voltage spark condition using the rotating disk electrode and an ac arc salt-cap technique. Considerable improvement in sensitivity for Al, Ca, and Pb is demonstrated with use of an argon atmosphere in the ac arc work.
R. E. Mansell, "The Spectrochemical Analysis of Magnesium and Its Alloys for Beryllium, Lead, and Other Trace Elements by Solution And Salt-Cap Techniques," Appl. Spectrosc. 15, 70-73 (1961)