定量分析宝石材料化学成分的激光诱导离解光谱方法研究

Quantitative Analysis of Chemical Composition of Gem Material by Using Laser-induced Breakdown Spectroscopy

主要针对宝石材料进行了激光诱导离解光谱技术定量分析方法的总结以及对比研究。选择外标法、自由定标法和归一化的外标法三种较为适用于宝石材料分析的方法进行了介绍。选取陨石玻璃、绿辉石、紫色翡翠以及硅酸盐玻璃等成分较为均匀的样品作为分析对象,使用中国地质大学(武汉)珠宝学院自制的激光诱导离解光谱设备,分别运用三种方法对其进行了定量分析的计算。定量分析结果显示,外标法易受成分变化及结构差异而造成的基体效应的影响,分析的准确度不高;自由定标法在分析成分复杂的样品时,其影响因素十分复杂,会产生较大的误差;归一化的外标法可有效校正基体效应的影响,其定量分析结果要优于前两者,虽然在微量元素分析准确度上尚需改进,但不失为一种较好的快速定量分析宝石材料的定量分析方法。

This paper is a comparative study of different methods for quantitative analysis of chemical composition of gem material. Three methods, that is, external standard calibration curve method, calibration free LIBS and external standard normalization method, have been discussed. And four homogeneous samples, nature glass, omphacite, purple jadeite and silicate glass, have been used as the analysis objects. A quantitative analysis has been completed by using the self-built laser-induced breakdown spectroscopy in China University of Geosciences （Wuhan）. The quantitative analysis results show that the external standard calibration curve method is easily affected by inhomogeneous matrix, which is often influenced by the different elements content or configuration, and thus the analytical accuracy is not high. In the analysis of the samples with complex components, the impact factors of calibration free LIBS are also very complex, which may lead to a greater error. The quantitative analysis results of the external standard normalized method are better than those of the first two, because the matrix effects can be revised. Although the analysis of trace elements still need to be improved on the accuracy,it can be a better quantitative analysis method for gem material.