Study On Inductively Coupled Plasma Mass Spectrometry In Analysising Exploration Geochemistry Samples

Using national geochemistry standard reference materials to prepare standard solution, which was used to obtain optimum determination parameters of ICP-MS such as nebulize gas, auxiliary gas, RF power and sampling depth. A method that decomposing samples with HF-HNO3 and extracting with 50% HNO3 for directly determining eighteen elements in different characteristic geochemistry samples by ICP-MS was developed. Interference of mass spectrometry and influence of blank were also discussed. The detection limits of this method were 0.01~ 6.41jig/g (6s). The precision were 2.84-9.36% (RSD%, n=12). The analytical results were in good agreement with the certified values.Decomposing samples with HF-HNO3-HC1O4, using 103Rh for internal standard, a method for directly determining gallium, indium and thallium in geochemistry samples by ICP-MS was developed. With the optimum parameters of ICP-MS, studied the results of internal standardrectification and TDS of major elements for matrix effect. The method that corrected the isobaric interference of masses was obtained. The detection limits of the method (6s) for gallium, indium and thallium were 0.059 g/g, 0.002g/g, 0.004 g/g. The precision (RSD%,n=12) were 2.97 ~ 5.33%. The analytical results of national standard reference materials by this method agreed well with the certified values.With the summarizing of articles determining Re present 10 years in China, putted forward the thinking of how to solve the problem determining super-trace Re in geochemistry samples. Discussed possibility of determining Re by ICP-MS. Studied fluxes, temperature and time in the course of decomposing samples. The detection limits of the method for Re was 0.4ng/g. Summed up major problems of the work and analyzed them.