A method is presented for the determination of trace quantities of tungsten, tantalum, niobium, molybdenum, vanadium, and chromium in magnesium alloys. In the procedure, the alloys are converted to their sulfates and excited by a 12 A dc arc for 70 s in a Harvey Crater graphite electrode. Magnesium sulfate synthetic standards are used. Minimum detectable concentrations ranging from 1 ppm molybdenum and chromium to 20 ppm tungsten and tantalum are indicated. The standard deviations range from 2.9 ppm for tantalum to 9.9 ppm for tungsten at the 50 ppm concentration range.
ASTM Methods for Emission Spectrochemical Analysis (1960), 3rd ed., pp. 23–27.
2.
AhrensL. H. and TaylorS. R., Spectrochemical Analysis (Addison-Wesley, Reading1961), 2nd ed., pp. 142–145.
3.
ASTM Methods for Emission Spectrochemical Analysis (1971), 6th ed., pp. 383–384.
4.
All decomposition, melting point, and boiling point temperature were obtained from WeastR. C., Handbook of Chemistry and Physics (CRC Press, Cleveland, 1974), 54th ed.
5.
WillardH. H.MerrittL.Jr., and DeanJ. A., Instrumental Methods of Analysis (Van Nostrand, New York, 1965), 4th ed., pp. 281–285.
