Determination of 36 Elements in Geochemical Samples by High Resolution Inductively Coupled Plasma-Mass Spectrometry

An analytical method for the simultaneous determination of Li, Be, P, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Nb, Mo, Cd, In, Sb, Cs, Ba, Hf, Ta, W, Tl, Pb, Bi, Th, U, Na₂O, MgO, Al₂O₃, K₂O, CaO and TFe₂O₃ in geochemical samples by High Resolution-Inductively Coupled Plasma-Mass Spectrometry (HR-ICP-MS) has been developed. Samples were decomposed using HF-HNO₃-HClO₄, and the residue was dissolved with aqua regia. The 36 elements in the solution were then determined directly by HR-ICP-MS. The optimal determination isotope and appropriate resolution for the 36 elements were selected to avoid the main spectra interferences from polyatomic ions and double charged ions. The detection limits (6σ) of the method were 0.002-2.031 μg/g for trace elements, and 10.0-100 μg/g for major elements (DF=1000). The relative standard deviation (RSD) was less than 10% (n=12). The method has been applied to the determination of 36 elements in national geochemical standard reference materials and the analytical results were in agreement with certified values.