Abstract:This article researches and proposes a mixed four acid (nitric acid-hydrofluoric acid-perchloric acid-sulfuric acid) decomposition system, which is compared with traditional four acid (hydrochloric acid-nitric acid-hydrofluoric acid-perchloric acid) or three acid (nitric acid-hydrogen Fluoric acid-perchloric acid) decomposition system has the advantages of less acid, no need to add in batches, and more complete decomposition of elements. A method for the simultaneous determination of tungsten, molybdenum, thallium, cadmium, bismuth, uranium, thorium, and chromium in phosphate rock samples by tetraacid open decomposition-inductively coupled plasma mass spectrometry was established, and the results were compared with the classic alkaline solution method. , Satisfactory accuracy. The effect of decomposition methods on volatile and insoluble elements was discussed. Appropriate analytical isotopes were selected and interference correction equations were used to eliminate mass interference. Using 103Rh and 186Re as internal standard elements, the dynamic drift of the analysis signal was effectively corrected. The detection limit is 0.010～0.35μg/g、 the precision is less than 6%, and the recovery rate of standard addition is between 93.4%～108%. Without increasing the analysis cost, a solution can also be used for the determination of other major and trace elements by ICP-OES and ICP-MS at the same time. The method is simple, fast, practical, and suitable for popularization and application.