Fe,Ca,Mg,K,Na in Mn 3O 4 product were determined by flame atomic absorption spectrometry, and chromium was determined by GFAAS after dissolving the sample with HCl(aq).

• 用盐酸溶解样品,火焰原子吸收光谱法测定四氧化三锰中铁、钙、镁、钾、钠,石墨炉原子吸收光谱法测定其中的铬。