Improvement and Study on the Determination of Iodine in Geochemical Samples by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

In this paper, the samples were treated with sodium carbonate and zinc oxide semi-melting method, and 732 cation exchange resin was used to separate a large number of cations from the solution after extraction with ethanol-boiling water, and the iodine in the sample solution was determined by Inductively coupled plasma mass spectrometry (ICP-MS) with pre-added internal standard method. By tuning the parameters of apparatus and optimizing the semi-melting procedure, the melting effect of the sample was improved. The measuring medium and internal standard element were optimized to eliminate the memory effect, and the stability of the results was improved. A robust and comprehensive ICP-MS method for iodine determination was established. Method validation was using Chinese national level standard substances for soil and stream sediment, with a relative error (RE) of 0.13-1.03% and a relative standard deviation (RSD) (n = 12) of 1.83-2.80%. The limit of detection (LOD) of the method was 0.039 mu g/g, and the limit of quantification (LOQ) of the method was 0.13 mu g/g. This study meets the requirements of sample analysis for geochemical survey and can be applied to the analysis and testing of large quantities of soil and sediment samples in geochemical survey.