ICP-MS Determination of 20 Trace Impurity Elements in High Purity Tantalum Pentoxide

Tantalum pentoxide sample was dried for 2 h at 105 ℃. After cooling to room temperature, the sample (0.500 0 g) was treated with 5 mL of HF and 2.5 mL of HNO₃ in a microwave digestor under programmed temperature elevation. Water was added to the digested solution to make the mass of solution attained to 50.0 g. The solution was used for ICP-MS determination of the 20 impurity-elements. Dynamic reaction cell technology was adopted to eliminate the interferences of polyatomic ions to Fe, with a flow-rate of 0.2 mL·min^-1 for CH₄ reaction gas and Rpq of 0.80, and the standard addition method was used to correct the matrix effect in preparation of standard curves. Values of detection limits (3s) found for the 20 elements were in the range of 0.009-0.53 μg·g^-1. Test for recovery was made by standard addition method, giving results in the range of 90.0%-116%, with RSDs (n=11) ranged from 1.8% to 17%.