电感耦合等离子体质谱法测定磷灰石中稀土元素分量和总量

Determination of the total amount of rare earth elements and its component in apatite by inductively coupled plasma mass spectrometry

基于电感耦合等离子体质谱法（ICP-MS）在稀土元素分析方面的优势,以HCl、HNO3、HF和HClO4溶解样品,控制He气流量为4.70mL/min,实现了动能歧视碰撞池（KED）-ICP-MS对磷灰石样品中稀土元素分量和总量的测定。通过选择合适的同位素避免了质谱干扰;通过稀释基体质量浓度不大于0.25mg/mL和选择45ng/mL^185 Re为内标进行校正相结合的方法消除了非质谱干扰。实验表明,在选定的实验条件下,各稀土元素在0～100ng/mL范围内与其对应的质谱强度呈良好的线性关系,校准曲线相关系数r为0.999 0～0.999 9,方法检出限为0.000 1～0.019 2ng/mL。将实验方法应用于磷灰石实际样品中稀土元素分量和总量的测定,所得结果的相对标准偏差（RSD,n=6）为1.1%～4.7%,加标回收率为96%～109%。

Based on the advantage of inductively coupled plasma mass spectrometry（ICP-MS）in analysis of rare earth elements,the determination of the total amount of rare earth elements and its component in apatite sample was realized by kinetic energy discrimination collision cell（KED）-ICP-MS with flow rate of He as 4.70mL/min after the sample was dissolved with HCl,HNO3,HF and HClO4.The mass spectrometry interference was avoided by selecting proper isotopes.The non-mass spectrometry interference was eliminated by diluting the mass concentration of matrix to below 0.25mg/mL and using 45ng/mL ^185 Re as internal standard.The results showed that the mass concentration of rare earth elements in range of 0-100ng/mL had good linearity to its corresponding mass spectrometric intensity under the optimized experimental conditions.The correlation coefficients（r）of calibration curves were between 0.999 0and 0.999 9.The detection limit of method was 0.000 1-0.019 2ng/mL.The proposed method was applied to determination of the total amount of rare earth elements and its component in apatite actual samples.The relative standard deviations（RSD,n=6）were between 1.1% and 4.7%.The recoveries were between 96% and 109%.