[Indirect determination of trace silicon in cobaltosic oxide by extraction-FAAS]

After the heteropolymobdate of silicon and phosphorus was formed, the heteropolymobdate of phosphorus was extracted into CH3COOH4H9 phase and P as interference element was separated. The heteropolymobdate of silicon was extracted by MIBK. Indirect determination of Si was achieved with Mo in MIBK determined by FAAS. Applying this method to the determination of silicon in cobaltosic oxide, the interferences of matrix cobalt and other coexistence elements were avoided. Compared to spectrophotometric method, the result is satisfactory.