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

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.