电感耦合等离子体质谱法测定碲金矿中碲

建立测定碲金矿中Te含量的检测方法,对碲金矿床的成因研究及金矿石矿产资源的综合开发利用意义重大。实验采用NaOH-Na₂O₂碱熔法处理样品,选择¹²⁵Te⁺为测定对象,通过选择数学校正方程校正了⁸⁵Rb⁴⁰Ar⁺、¹⁰⁹Ag¹⁶O⁺对¹²⁵Te⁺的质谱干扰,以10.0ng/mL ¹⁰³Rh为内标,实现了电感耦合等离子体质谱法(ICP-MS)对碲金矿中Te的测定。对样品处理方法进行了选择,同时对Na₂O₂的用量进行了优化,确定采用0.1g NaOH-0.6g Na₂O₂处理样品;探讨了仪器采样深度对Te和Rh信号强度的影响以及对双电荷产率(Ba²⁺/Ba⁺)和氧化物产率(CeO⁺/Ce⁺)的影响,确定采样深度为150step;考察了测定液中乙醇在0~6%(体积分数,下同)范围内对Te信号强度的影响,结果表明,3%乙醇对质谱信号增强效果显著。实验方法的线性范围为0.020~200μg/g,校准曲线相关系数为0.9999,方法检出限和测定下限分别为0.015μg/g和0.049μg/g。选择碲金矿标准物质GBW07858、GBW07859进行方法验证,所得结果与认定值基本保持一致,相对标准偏差(RSD,n=12)为2.6%~5.9%,回收率为92%~108%。采用实验方法对碲金矿实际样品进行分析,测得结果与氢化物发生-原子荧光光谱法(HG-AFS)基本一致。

Determination of tellurium in calaverite by inductively coupled plasma mass spectrometry

The establishment of detection method for Te in calaverite has important significance for the genetic study of calaverite ore deposit as well as the comprehensive development and utilization of gold ore sources.The sample was treated by NaOH-Na₂O₂ alkali fusion method. ¹²⁵Te⁺ was selected as the determination objective. The mass spectrometry interference of ⁸⁵Rb⁴⁰Ar⁺ and ¹⁰⁹Ag¹⁶O⁺ with the determination of ¹²⁵Te⁺ was corrected by mathematical correction equation. 10.0ng/mL ¹⁰³Rh was selected as the internal standard. The determination of Te in calaverite by inductively coupled plasma mass spectrometry (ICP-MS) was realized.The sample treatment methods were selected. Meanwhile, the dosage of Na₂O₂ was optimized and 0.1g NaOH-0.6g Na₂O₂ was finally used for sample treatment. The influence of sampling depth on the signal intensity of Te and Rh as well as the double charge yield (Ba²⁺/Ba⁺) and oxide yield (CeO⁺/Ce⁺) was discussed. The sampling depth was 150-step. The effect of ethanol concentration (0-6%, volume fraction, the same below) in testing solution on the signal intensity of Te was investigated. The results showed that 3% ethanol had significant enhancing effect on mass spectrometry signals. The linear range of method was 0.020-200μg/g. The correlation coefficient of calibration curve was 0.9999. The detection limit and low limit of determination was 0.015μg/g and 0.049μg/g, respectively. The certified reference materials of calaverite (GBW07858 and GBW07859) were used for method validation. The found results were consistent with the certified values. The relative standard deviations (RSD, n=12) were between 2.6% and 5.9%. The recoveries were between 92% and 108%. The proposed method was applied to the analysis of actual calaverite sample, and the found results were consistent with those obtained by hydride generation-atomic fluorescence spectrometry (HG-AFS)