Abstract:Two pretreatment methods were established for the determination of 15 rare earth elements (Lu, La, Ce，Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y) in shale by KED-ICP-MS with microwave digestion and wet digestion. The Rh and Re through the introduction of online as internal standard. The results indicated that the linearity of REES were good in range of 0 ~ 100ng/mL, with the correlation coefficient higher than 0.998 and the detection limit within 0.003 ~ 0.034 mg/kg, the relative standard deviations were between 1.28 % and 8.22 % (n=6). Because of high organic matter content in shale, the proportion of perchloric acid and sulfuric acid should be increased appropriately with wet digestion. The microwave digestion was a rapid and efficient method for sample decomposition with less acid consuming, better detection limit and accuracy precision compared with wet digestion.