Abstract:Carbon shale contains a large amount of carbonized organic matter, the molybdenum and tungsten are easily hydrolyzed in a single hydrochloric acid solution, and The complete digestion of samples and the prevention of formation of tungstic acid and molybdic acid are the keys to the accurate determination of tungsten, Molybdenum and scandium in carbonaceous shale. In this paper, HF-HNO3-HClO4 was added to cover the digestion. The formation of steam reflux, complete solution sample, using tartaric acid-hydrochloric acid system leaching, effective prevention of precipitation of tungstic acid and molybdic acid resulting in low results. A method for the determination of Tungsten, Molybdenum and scandium in carbonaceous shale by Inductively coupled plasma mass spectrometry (ICP-MS) was established. The determination results show that the linear relationship of each element is good in the range of 0.01 ~ 200.0 μg/L, the correlation coefficient is above 0.9999, and the detection risk of the method is 0.011~0.045 μg/g. The relative standard deviation (RSD, n=11) was 0.77% ~ 2.6%, and the recovery rate was 94 %~107%.