Technical development of arc-emission spectroscopy and its application in geological sample analysis

The characteristic lines can be emitted in the process that the tested elements are excited by high energy arc and then vaporized or dissociated into gaseous atoms. The arc emission spectroscopy can quantify the composition and content of samples by detecting the wavelength and intensity of the characteristic spectral lines. This paper discusses the development and application of the arc emission spectroscopy in the field of geological analysis from the perspectives of method optimization and composition and ratio of buffer. The two aspects have a significant impact on key performance indicators such as precision, accuracy and detection limit of the analytical technology. In terms of the method optimization, the full spectrum emission spectrometry method has been developed. The analytical procedure was greatly simplified by eliminating the tedious experimental steps such as developing, fixing, spectrum and metering. The analysis results have been digitized, and the analysis efficiency has been greatly enhanced. Some elements such as silver, tin and boron have been successfully detected by using its all spectral lines. Analytical lines can be selected based on the sample content so the linear range of the detected elements was expanded. In terms of buffers, the research progress on components and ratios of various buffers enhances the accuracy and reliability of analysis results. Nowadays, the arc emission spectroscopy has been adopted in the geo-sample analysis of silver, tin and boron by the laboratory of Nanjing Center, China Geological Survey, which provided abundant experimental data with good mapping effect and important information on the mineral deposits in the working area, playing a key role in geological survey. The future research will be continuously focused on the optimization of experimental method and the development of new buffers, so as to technically support the national new round of ore-prospecting breakthrough strategic action.