Determination of 6 Elements in Geochemical Sample by Inductively Coupled Plasma Mass Spectrometry with High Pressure Sealed Digestion

A method for determination of 6 elements, including boron, cobalt, molybdenum, cadmium, germanium, and beryllium, in geochemical sample by inductively coupled plasma mass spectrometry (ICP-MS) with high pressure sealed digestion was proposed. 0.100 0 g of the sample was taken into a polytetrafluoroethylene crucible, and 3 mL of 50% aqua regia(a mixture of hydrochloric acid-nitric acid-water at a volume ratio of 3∶1∶4) and 0.5 mL of hydrofluoric acid were added, settling for 30 min. Then the mixture was performed by high pressure digestion in a 180 ℃ oven for 18 h. After digestion, its volume was made up to 50 mL with water, in which 6 elements were determined by ICP-MS. As shown by the results, linear relationships between the corresponding spectral peak intensity and internal standard spectral peak intensity ratios and mass concentrations were found within 200 μg·L⁻¹ for boron and cobalt elements and 10.0 μg·L⁻¹ for molybdenum, cadmium, germanium, and beryllium elements, with detection limits(3s) of 0.005—0.12 mg·kg⁻¹. The method was used to analyze national standard materials, and the determined values were basically consistent with the certified values, with RSDs(n=12) of the determined values less than 8.0%. The method was also used to analyze two actual geochemical samples, and the determined results were basically consistent with those by DZ/T 0279—2016, with RSDs (n=12) less than 5.0%.