Study on the Elimination and Correction of Spectral Interferences in the ICP-AES Determination of Mo、 W、 Ta、 Re and Ru in Nickel-Based Single Crystal Superalloys

A portion (0.100 0 g) of the Ni-based single crystal supper alloy sample was dissolved in a PTFE beaker with 9 mL of HCl and 1 mL of HNO₃ and 2 mL of HF successively by heating. The solution was cooled and 2 mL of 500 g·L^-1 tartaric acid solution were added and the solution was diluted to 100.0 mL with water in a plastic volumetric flask. Five alloy elements (Mo, W, Ta, Re and Ru) were determined this sample solution by ICP-AES under the working condition of the instrument. Analytical spectral line chosen for these elements were 204.598, 207.911, 240.063, 197.312, 240.272 nm respectively. It was found that besides Re, spectral interferences were encountered in the determination of the 4 remainder elements, leading to serious errors of the analytical results. To overcome this trouble, in addition to the elimination of matrix effect due to Ni, by the matrix matching method, the matrix method of mixed correction coefficients was tested to correct the spectral interferences. Base on the known values of mass concentrations of the testing elements and their ICP-AES determined values in mass concentrations, values of matrix K of mixed correction coefficients were calculated according to the given formula, and by applying the values of matrix K, the errors encountered could be corrected. Precision and recovery of the ICP-AES method after correction by the matrix method of mixed correction coefficients were tests, giving RSDs (n=11) for the 5 elements less than 1.5% and values of recovery obtained by standard addition method in the range of 97.0%-105%.