Abstract: On the basis of the theory of plant trace geochemistry prospect mine an analytic method of rare elements in plant is established, providing a rapid credible new means for plant was ashed by the method of high temperature furnace bake over a weak flame. The hydrof luoric acid-hydrochloric acid-nitric acid-vitriol (HF-HCl-HNO₃-H ₂SO₄) system was used for the determination of 15 rare earthelements in the ash of plant by inductively coupled plasma mass spectroscopy (ICP-MS). The method of inductively coupled plasma mass spectroscopy can reduce the error introduced by chemistry separate and enrichment complex operating process, the operation is simple and the examine is quickly. The result of method is in agreement with the standard of nationality standard substance GBW07603. The experiment method measurement accuracy is 3.00%～14.10% in relative error, t heprecision(relatively standard deviation, number=8) is in the range of 3.22%~20.00%.

Key words: inductively coupled plasma mass spectroscopy, plant ash, rare ea rth element