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采用HF-HClO4-HNO3-H2SO4分解样品,王水提取,选用4个国家一级标准物质制备成标准系列校准,ICP-MS法直接测定地球化学样品中的Cd。选择103Rh为内标,确定了仪器的最佳分析条件,研究了Zr,Sn对Cd的干扰,选择114Cd作为测定同位素,采用数学公式校正了Sn对Cd的同质异位素干扰,方法检测限(3s)为6.3×10-3μg/g,RSD(n=12)为3.9%～6.6%。经国家一级标准物质验证,测定值与标准值吻合较好。该方法适用于地球化学样品中的微量Cd的测定。
The sample was decomposed by HF-HClO4-HNO3-H2SO4 and extracted with aqua regia. Four national primary standards were used to prepare a standard series of calibrations. ICP-MS was used to directly determine Cd in geochemical samples. 103Rh was selected as the internal standard to determine the optimum analytical conditions for the instrument. The interference of Zr and Sn on Cd was studied. 114Cd was selected as the isotope and the isotopic interference of Sn to Cd was corrected by mathematical formula. The detection limits (3s) of 6.3 × 10-3 μg / g and RSD (n = 12) of 3.9% -6.6%. The national standard material verification, the measured value is consistent with the standard value is good. This method is suitable for the determination of trace Cd in geochemical samples.