Interference removal in mass spectrometry for the determination of trace gold，mercury and selenium in nickel-based superalloys by ICP-MS/MS

：The traditional single-quad inductively coupled plasma mass spectrometry（ICP-MS）cannot eliminate the mass spectrometry interference caused by the polyatomic ions formed by Ta，W and Ni elements and carrier gas Ar in the determination of trace impurity elements Au，Hg and Se in the second-generation nickel-based single crystal high-temperature alloy CMSX-4. Based on triple quadrupole-inductively coupled plasma mass spectrometry （ICP-MS/MS）technology，the working conditions of the instrument were studied by investigating the effects of mass spectrum interference cancellation under different collision or reaction modes （No Gas mode， He mode，O2 on-mass mode，and O2 mass-shift mode）. A method was established for the determination of trace impurity elements Au，Hg and Se in CMSX-4. The results showed that the mass spectrometry interference of TaO+ on Au+ and WO+ on Hg+ can be effectively eliminated by using O2 on-mass mode；the mass spectrometry interference of NiO+ and ArAr+ on Se+ can be effectively eliminated by using O2 mass-shift mode. Considering the signal intensities and background equivalent concentrations of the 3 elements to be measured，the O2 flow rate was determined to be 0.60 mL/min. Also，133 Cs was selected as the internal standard element for the measurement of Au and Hg，while103 Rh was selected for the measurement of Se after comparing the effects of correcting matrix effects and analyte signal drift by internal standard elements. The linear equations of Au，Hg and Se have been established under the optimal conditions，and the linear correlation coefficients were 0.9991. The detection limits of Au，Hg，and Se were 0.11-0.29 ng/mL. The relative standard deviations （RSDs）were 2.0%-9.5%，and the spiked recoveries of Au and Hg were 96.1%-107.2% by determining the samples of 3 supplemental levels and the recoveries of the bidding recycling of 9 groups. The results showed no significant difference between the identification value by t-test of Se in the standard substance in the nickel-based high-temperature alloys. © 2024, Youke Publishing Co.,Ltd. All rights reserved.