ICP-AES Determination of 11 Elements in Alunite Ore

The alunite ore sample (0.200 0 g) was mixed thoroughly with 1.000 0 g of the flux (Na₂CO₃+Na₄B₂O₇, with mass ratio of 2 to 1) in a Pt crucible and fused at 950℃ for 30 min. After cooling, the melt was taken up with 50 mL of HCl (1+9) solution and its volume was made up to 100 mL. This solution was used for ICP-AES determination of contents of Fe, Ca, Mg, Cu, Ti, Pb, Cr and Ga. For determination of K, Al and Si with higher contents, an aliquot (5.0 mL) of the above sample solution was taken and diluted to 100 mL with water. To eliminate the matrix effect, 2 conditions, i.e., ① the matrix matching method and ②matrix matching method with addition of 2 mg·L^-1 of Y as internal standard, were tested separately. As shown by the testing results, accuracy of analytical results obtained under either of the 2 conditions mentioned above were attained at nearly the same level, but precision of the results obtained under the latter condition were better than those obtained under the former condition.