电感耦合等离子体质谱法测定华阳川铀铌铅多金属矿中铀

采用HF-HNO₃-HClO₄敞开酸溶,HNO₃-H₂O₂复溶的方法进行样品前处理,选用10μg/L¹⁸⁵Re作内标,建立了电感耦合等离子体质谱法(ICP-MS)测定陕西华阳川铀铌铅多金属矿中铀的方法。实验表明,在选定的实验条件下,铀的质量浓度在10~100ng/mL范围内与其质谱强度呈良好的线性关系,校准曲线的相关系数为0.9999,方法检出限为0.007μg/g。采用实验方法测定铀质量分数为8.46~1255μg/g华阳川多金属矿石样品,6次平行测定的相对标准偏差(RSD)为0.71%~1.8%。采用实验方法分析一系列与华阳川铀铌铅多金属矿样成分相似的铀矿石标准物质,相对误差小于2.5%。采用标准方法EJ/T267.5—1984和实验方法进行方法对照,结果表明对质量分数大于200μg/g的华阳川多金属矿样品,二者的分析结果基本一致。

Determination of uranium in Huayangchuan uranium-niobium-lead polymetallic ore by inductively coupled plasma mass spectrometry

After the sample was pretreated by dissolution with HF-HNO₃-HClO₄ in open system and redissolution with HNO₃-H₂O₂, a determination method of uranium in Huayangchuan polymetallic ore in Shaanxi was established by inductively coupled plasma mass spectrometry (ICP-MS) with 10μg/L ¹⁸⁵Re as internal standard. The results indicated that the mass concentration of uranium in range of 10-100ng/mL showed good linear relationship with its mass intensity under the selected experimental conditions. The linear correlation coefficient of calibration curve was 0.9999. The detection limit of method was 0.007μg/g. The experimental method was applied to determination of Huayangchuan polymetallic ore samples with mass fraction of uranium in range of 8.46-1255μg/g. The relative standard deviations (RSD) for six parallel determination were between 0.71%-1.8%. The proposed method was applied to determination of uranium ore certified reference materials which have similar mineral composition with Huayangchuan polymetallic ore. The relative errors were less than 2.5%. The proposed method was also compared with standard method of EJ/T 267.5-1984. The results indicated that the determination values of uranium by the above two methods were consistent for Huayangchuan polymetallic ore samples with uranium content larger than 200μg/g.