Abstract: Four kinds of soil were digested by electric heatingboard digestion and microwave digestion with two kinds of acid system respectively.Subsequently,concentration of Cu、Pb、Cr、Zn、Mn in the soils was determinated.The results showed that concentration of Cu、Pb、Zn in the standard soil sample digested by the four methods in good agreement with the reference values.The determinated value of Mn concentration in the standard soil sample digested by the two microwave digestionmethods in good agreement with the reference value.Only determinated valueof Cr concentration in the standard soil sample digested by microwave digestion method with HNO₃+HF+HClO₄ agreed with the reference value.There was no significant differencein the concentration of Cu、Pb、Zn in the standard soil sample,soil A (sampled from biological garden of Guangxi Normal University),soil B and soil C (sampled from recovery region and tailing region of Guangxi Lipu Manganese mine).But there was significant difference in the concentration of Cr in the four soils andin the concentration of Mn in the soil B.Conclusively,microwave digestion method with HNO₃+HF+HClO₄ was the most ideal method which could digest effectively all of the five heavy metals in the soils.

Key words: soil digestion, microwave digestion, electric heatingboard digestion, heavy metals