Abstract:In order to improve the yield of heavy metals in soil digestion pretreatment, the content of heavy metals in soil was determined by microwave digestion/electrothermal plate combined inductively coupled plasma mass spectrometry (ICP-MS). The effects of combined digestion solution and temperature on microwave pretreatment were analyzed. The results show that the higher the proportion of HNO3 in the digestion solution, the higher the yield of Cr, Co, Cu, CD and other heavy metals; HF can remove the residue and improve the Cr and Cu yield. The optimal pretreatment digestion conditions were microwave digestion with HNO3 6ml + HF 2ml, and 1ml HClO4 was removed on 155℃ electrothermal plate. The practical application of national certified reference materials of soil GBW07401(GSS-1)and GBW07452(GSS-23) shows that the accuracy and stability of the test are improved significantly after the optimization of the pretreatment conditions. In addition, when Rh is used as internal standard, the stability and accuracy of the method are higher than that of SC and Ge. It provides a reference for the revision of the soil heavy metal determination national standards.