Abstract：A method is described for the determination of molybdenum in steel and superalloy by glow discharge mass spectrometry (GDMS). The interference effect of metallic argides CrAr+、FeAr+ and NiAr+ on the determination of molybdenum isotopes were investigated in detail. The interferences were corrected by the methods such as selecting un-interferential isotopes, deducting with abundance ratio of isotopes, deducting by calibration curve. These methods were used in the determination of low alloy steel, stainless steel and superalloy standard samples, and the determined values were in agreement with the certified values. It showed that the effect of argides CrAr+、FeAr+ and NiAr+ on the determination of molybdenum isotopes is removed successfully, and the content of molybdenum has been determined exactly.
