采用激光诱导击穿光谱(LIBS)技术定量分析缅甸翡翠中Fe元素的浓度。 选择Fe元素的275.57 nm光谱线作为定量分析谱线, 选取Si元素的288.17 nm光谱线作为内标谱线, 选取12个缅甸翡翠样品作为研究对象, 以其中9个样品绘制了传统定标法和内定标法的Fe元素定标曲线, 并将定标曲线用于3个检验样品的Fe含量的实际预测。 实验结果表明, 采用传统定标方法时, 定标样品光谱强度的相对标准偏差(RSD)在1.4%～8.3%之间, 所建立的Fe元素浓度含量定标曲线的拟合相关系数R2为0.979, 使用该方法建立的定标曲线对3个检验样品中Fe元素含量进行测定, 最大相对误差为10.6%; 而采用内定标法时, 定标样品光谱强度的比值(IFe/ISi)的相对标准偏差(RSD)在0.9%～5.7%之间, Fe的拟合相关系数R2达到0.989, 样品中Fe元素的测定相对误差均可降低到7%以下。 结果证明, 利用内定标法定量分析翡翠中Fe的含量比传统定标法相对误差更小, 采用LIBS技术结合内定标法更适于缅甸翡翠样品中Fe元素定量分析。

Using laser-induced breakdown spectroscopy (LIBS), quantitative analysis of iron(Fe)in Myanmar jades has been studied in this work. Ion’s LIBS spectrum at 275.57 nm was chosen for quantitative spectral analysis, and Silicon’s LIBS spectrum at 288.17 nm was selected as internal standard line. Twelve pieces of jade from Myanmar were selected as specimens. Nine of them were applied to construct the spectral calibration curves of iron with traditional method and internal standard method, and the content of iron in another three specimens selected as test samples was practically predicted. The experimental results show that the relative standard deviation of the intensity of iron is between 1.4% and 8.3%, while the fitting correlation (R2) of calibration curve is 0.979, and the maximum relative error of test samples is 10.6% when traditional method is used. While the internal standard method was used, the relative standard deviation of the intensity ratio of iron and silicon is between 0.9% and 5.7%, while the fitting correlation (R2) of calibration curve is 0.989, and the relative error of test samples reduces to under 7%. The analyzed results indicate that using LIBS coupled with internal standard method is much better to quantitatively analyze the content of iron in Myanmar jades compared with applying traditional method, as internal standard method can reduce the relative error of measurement.