Determination of Elemental Content in Geological Samples by One-Time Acid Dissolution and Inductively Coupled Plasma-Mass Spectrometry

The methods of HCl-HNO₃-HF and HCl-HNO₃-HF-HClO₄ were improved to overcome the incomplete decomposition of refractory elements and bad replication results of volatile elements. A new analysis method has been developed for 15 rare earth elements and common trace elements by ore dissolution and determination. Analytical quality and efficiency have been greatly improved. Geological samples were dissolved with mixed acids of HCl-HNO₃-HF-HClO₄-H₂SO₄ in 30 mL teflon crucible on a hot plate. The salts were dissolved and extracted by 50% reverse aqua regia and diluted to constant volume. 45 elements in the samples were determined simultaneously by ICP-MS with 10 ng/mL Rh as the internal standard and three on-line injections. The effect of volatile elements are discussed in detail for the decomposition method. The certified reference material of rock (GBW07106), stream sediment (GBW07303) and soil (GBW07429) were analyzed to test the method. Results are in good agreement with certified values. Standard deviations of the method are 0.03%-4.97%. This method is rapid, simple and practical with high precision.