Abstract: The sample of Mn₃O₄ is digested with HCl, then Lasalt and Srsalt are added as release agents to offset 70 percent of influence of matrix Mn, the contents of calcium and magnesium are determined directively which achieve favorable result. This method proved to be convenient, rapid and exact. The recovery of method is 95. 8%~98. 7% , the relative standard deviation is 2.43%~ 3.28%.

Key words: Mn₃O₄, compound release agent, Calcium, Magnesium, flame atomic absorption spectrography