ICP-MS Determination of Impurity Elements in Solar Energy-Grade Polycrystalline Silicon

The sample of polycrystalline silicon was treated with a mixture of HF and HNO3, and the contents of 23 impurity elements in the sample solution were determined by ICP-MS. Appropriate resolution ratio was selected to eliminate interference of polyatomic ion effect on part of the determined elements. Values of detection limit (3s) for the 23 elements were found in the range of 0.3-19.7 ng·g-1. The proposed method was applied to the determination of samples of solar energy-grade polycrystalline silicon, giving values of recovery and RSD′s (n=11) in the ranges of 85.2%-111% and 0.9%-4.6% respectively.