Determination of multiple impurity elements in high-temperature alloys based on nickel-matched-inductively coupled plasma atomic emission spectrometry

In this study, an analytical method based on nickel matrix matching was established for the determination of multiple impurity elements in high-temperature alloys using inductively coupled plasma atomic emission spectrometry (ICP-AES). The samples were digested in a hydrochloric acid-nitric acid-hydrofluoric acid system. The suitable analytical wavelengths, optimal instrumental parameters and strategies for the correction of coexisting element interferences were determined through systematic condition optimization. The graded calibration curves were prepared according to the concentration ranges of target elements and the nickel matrix matching technique was employed to effectively eliminate matrix effects. The accuracy of the method was validated by analysis of certified reference materials (CRMs) and spike recovery experiments. The measured values of CRMs were all within the range of their expanded uncertainties and the recoveries ranged from 93.4% to 106.2%. The eleven independent parallel measurements were performed on three samples at different concentration gradients and the relative standard deviations (RSDs) from 0.54% to 4.39%. A collaborative study was further conducted with thirteen authoritative laboratories. The outliers were identified by the Grubbs and Cochran tests, and the repeatability limits and reproducibility limits were calculated. In summary, the results demonstrate that the proposed method exhibits excellent accuracy and precision, and is fully competent for the quantitative determination of multiple impurity elements in high-temperature alloys.