微波密闭消解-电感耦合等离子体质谱法(ICP-MS)测定矿石中金和银

建立了微波密闭消解-电感耦合等离子体质谱法(ICP-MS)测定矿石中痕量元素金和银。考察了微波消解试样、基体效应、质谱干扰,并进行了ICP离子源以及质谱仪检测条件和微波消解参数的最优化。以标准加入法消除复杂多变的矿石基体对分析信号的影响,干扰校正方程消除多原子离子等质谱重叠影响。测定矿石中金银结果表明:回收率为197Au106%～113%、107Ag95%～105%、109Ag93%～103%,相对标准偏差RSD<6%(n=8),检测限197Au、107Ag、109Ag分别为10、3、6ng/g。方法适用性强,可满足不同类型矿石中超痕量金银的测定,分析步骤少,操作简便,快捷准确。

Closed Microwave Digestion- Inductively Coupled Plasma Mass Spectrometry with Standard Addition for Determination of Gold and Silver in Ore

A new method for simultaneous and direct determination of trace Ag and Au in ore by inductively coupled plasma mass spectrometry (ICP-MS) with closed microwave digestion has been established. The operating conditions of microwave sample digestion, matrix effect and mass interference have been investigated. The operating parameters of the ICP ionization source and mass spectrometer and microwave digestion conditions were optimized. Standard addition method was used in order to eliminate the matrix effects on signals during the analysis of complex and varied ores. Interference correction equations were applied to data treatment to eliminate mass overlapping effects caused by polyatomic ion. The results show that: the recovery of 197Au ,107Ag and 109Ag are in the range of 106% ~ 113%, 95% ~ 105%, 93% ~ 103%, respectively, with the relative standard deviation ( RSD) of <6% (n = 8). The detection limits of 197Au ,107Ag, 109Ag are 10,3 and 6 ng/g, respectively. The method has good applicability and is suitable to determine ultra-trace gold and silver in the different types of ores. In summary, the advantages of the method include simple analytical procedure, easy instrument operation, short time for obtaining accurate results.