【摘要】 试验了 1 0 0～ 70 0 μg/LBa的氧化物对Eu产生的干扰 ,干扰程度与Ba量呈线性 ,其相关系数r在 0 .9986～ 0 9995。用模拟样品溶液对不同含量的Ba对Eu的干扰采取了简单的数学方法校正 ,校正后的结果在误差允许范围之内。对小麦和人发标准物质中Ba氧化物对Eu的干扰及校正效果进行了比较。结果表明 ,在所使用的仪器条件下 ,这两个标准物质中的Ba对Eu的干扰必须校正。研究了 μg/L水平的轻稀土氧化物对重稀土元素的干扰程度 ,其中La、Ce和Pr的氧化物干扰比较严重 ,其氧化物产率 (% )分别为 2 0 ,2 79和 3 2 6。此类干扰问题可以通过选择无干扰或干扰相对较低的同位素 ,或通过将稀土标准按轻稀土和重稀土元素分组来解决 ,但对于小麦和人发标准物质 ,由于样品中Pr含量较低 ,选择1 57Gd测定时其干扰可忽略不计更多还原

【Abstract】 The oxide interference and its correction for the determination of rare earth elements (REEs) at sub ng/g levels in human hair and wheat flour reference materials by ICP MS was discussed in this paper. The linear regression indicates that the contribution of BaO at 100 to 700 μg/L levels on 151 Eu and 153 Eu peaks is a linear correction with correlation coefficients of 0.998?6 and 0.999?5 respectively. A simple mathematical interference correction method was developed and verified. The results from the analysis of Eu in human hair and wheat flour reference materials with and without interference correction show that under the selected instrumental conditions the interference from the Ba on Eu in the samples must be corrected. The results after interference correction by proposed method are within an acceptable range. The interference from light REEs on middle REEs and heavy REEs are also studied. The results show that the interference from oxides of La, Ce, Pr and Nd are more serious and careful selection of the measured isotopes and use of two groups of calibration solutions (LREEs and HREEs) separately are recommended.更多还原