ICP-MS Determination of Impurity Elements in High-Purity Aluminum

The sample of high-purity aluminum was treated with HCl (1+1) solution by microwave assisted digestion, and the contents of Ti, Fe, Cu, Zn, Ga, Ag, Cd, In and Pb in the sample solution were determined by ICP-MS. Appropriate isotopes of the elements determined were selected to overcome the mass spectrometric interferences and definite amount (50 μg·L-1) of mixed internal standard of Cs and Ge was added to compensate the matrix effect. Interference of polyatomic ion effect to part of the determined elements was eliminated by adoption of the collision cell technique. Values of detection limits (3s) for the 9 elements were found in the range of 0.003-0.042 μg·L-1. Precision of the method was tested by analyzing a high-purity aluminum, values of RSD′s (n=10) found were ranged from 2.9% to 9.5%. The proposed method was applied to the determination of standard sample of pure aluminum, the results obtained were in consistency with the certified values.