高分辨电感耦合等离子体质谱法测定地球化学样品中的36种元素

摘要

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, A12O,, 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-HC1O4, 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 (6a) of the method were 0. 002 -2.031 (Xg/g for trace elements, and 10. 0 - 100 jig/g for major elements ( DF = 1000). The relative standard deviation (RSD) was less than 10% (re = 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.%土壤和水系沉积物地球化学样品经氢氟酸-硝酸-高氯酸敞开酸溶消解,王水提取,试液直接用高分辨率电感耦合等离子体质谱法( HR - ICP - MS)同时测定其中的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、TFe2O3等36种组分.对各元素的测定同位素及分辨率进行优选,有效消除了绝大多数多原子及双电荷离子干扰的影响.痕量元素的方法检出限(6σ)在0.002 ～ 2.031 μg/g之间,主量元素的检出限(6σ)在10.0 ～ 100 μg/g之间(稀释因子=1000),所有元素的相对标准偏差(RSD,n=12)均小于10％.方法经国家一级地球化学标准物质验证,测定值与标准值吻合.