FAAS Determination of Manganese in Silicon-Aluminum Alloy (FeAl40Si15) with Addition of Surfactants to Restrain Interference of Al(Ⅲ)

The sample (0.200 0 g) was dissolved with HNO3 (10 mL), HF (5 mL) and HClO4 (8 mL) in a PTFE beaker heated at low temperature, and the solution was evaporated to fume of HClO4, after cooling, HClO4 (2 mL) was added and fumed again to expel HF. Cool again and the salts were taken up with 2 mL of HNO3 (1+5) and the solution was transfered into a 100 mL volumetric flask. A portion of 100 g·L-1 OP solution (2 mL) was added to the solution to restrain the interference of macroamounts of coexisting Al(Ⅲ), and the solution was diluted to 100 mL with water. Manganese in the solution was determined by FAAS under the prescribed conditions. Linear relationship between values of absorbance and mass concentration of manganese was obtained in the range within 0.50 mg·L-1, with detection limit (3s) of 0.046 mg·L-1. The proposed method was applied to the analysis of silicon aluminum alloy (FeAl40Si15), giving values of RSD′s (n=5) for manganese in the range of 1.3%-1.9%. Test for recovery was performed by standard addition method, giving values of recovery in the range of 102%-103%.