ICP-AES Determination of Aluminum, Magnesium and Phosphorus in Manganese Ores with Microwave Assisted Sample Digestion

The manganese ore sample was digested with HCl, HNO3, H2O2 and HF in a closed digestion vessel and heated in a microwave digestor. The solution obtained were transferred to a PTFE 100 mL volumetric flask, diluted to mark with water, and used for ICP-AES analysis. Use of boric acid to complex the free HF was not adopted in this case for avoiding its inferference. To eliminate the matrix interference, definite amount of manganese was added to the test solutions in the preparation of standard curves. Analytical spectral lines selected for the determination of Al, Mg and P were those with the wavelengths of 396.152, 280.270, 185.942 nm respectively. Two CRM′s of manganese ores were analyzed by the proposed method, giving results of the 3 elements in conformity with the certified values and values of RSD′s (n=11) ranged from 0.63% to 1.18%.