Study On The Elimination Of Polyatomic Molecule Ion Interferences By ICP-MS For Geochemical Samples

ICP-MS is a kind of strong current multielement analysis instruments, it can provide excellent for most of the elements in the periodic table, detection limit,and can rapid simultaneous multielement analysis, as many elements in geochemical samples and test conditions. But research shows that when the sample matrix complex and type variable,it is derived from plasma of polyatomic molecule ions with the same as the quality target of isotope mass spectrum overlap, restricted the ICP-MS application in complex matrix samples tested.This paper reduces the introduction of interference substances and eliminates the interference of two aspects, proposed the microwave pretreatment methods of nitric acid extraction, and combining with 8 pole collision reaction pool technology and dilution air system, studies the icp-ms polyatomic molecule ion interference elimination technique,established the microwave digestion icp-ms determination of 43 kinds of elements in geochemical samples at the same time the new method.Experimental results show that the microwave nitric acid extracted by pretreatment method, the geochemical samples can be eliminated completely, each element of the detection limit can satisfy the requirements of the test and the quality control standard. Through the contrast experiment with original pretreatment methods, you can see that the new method can overcome the loss of volatile elements and contamination of Cr and Ni. What is more important not to join the hydrochloric acid, can reduce the icp-ms polyatomic molecule ion interference produced when the sample is measured. At the same time, combined with the optimized experimental conditions of changing the pole collision reaction pool technology and HMI dilution air system, basically eliminated the polyatomic molecule ion disruption in geochemical samples. Established by microwave digestion icp-ms determination of 43 kinds of elements in geochemical samples at the same time the new methods for rock and soil and stream sediments of microelements and trace elements in national standard substance test results satisfactory test results accord with the actual samples the lab test of geology and mineral resources and quality control standard for part 4 ".