Determination of Trace Elements in Nickel-based High-temperature Alloy by High Resolution Plasma Mass Spectrometry

The nickel content of nickel-based high-temperature alloy is between 50% and 70%, and the alloy contents of chromium, iron, cobalt, molybdenum, aluminum, titanium and tungsten are within 20%. A method of high resolution plasma mass spectrometry was established to determine the trace elements in nickel-based high-temperature alloy. According to the principle of large isotope abundance, small interference and high sensitivity, the isotopes and resolution of the elements to be measured were optimized, the interferences of most of the multi-atom and double-charged ions were effectively eliminated. The mass spectral interferences of matrix, compositions of alloy and dissolving acid on the trace elements were investigated. The appropriate internal standard of caesium was selected to overcome the matrix effect and reduce the signal drift. Chromium was extracted by methylisobutylone, the extraction efficiency reached up to 99.7%, which eliminated the mass spectral interference of principal component molybdenum in the nickel-based high-temperature alloy. The linear correlation coefficient of the calibration curve was greater than 0.999, and the method detection limit was between 0.002 1 and 0.074 μg/g. The trace elements in the reference material was analyzed, the relative standard deviation (RSD, n=6) was between 2.9% and 7.8%, and the measured value was very consistent with the standard value. This method is simple, fast, accurate and reliable, which can meet the requirement of trace elements determination in nickel-based high-temperature alloy.