Major elements analysis in bituminous coals under different ambient gases by laser-induced breakdown spectroscopy with PLS modeling  

作　　者：Zhe Wang Ting-Bi Yuan Siu-Lung Lui Zong-Yu Hou Xiong-Wei Li Zheng Li Wei-Dou Ni 

机构地区：[1]State Key Lab of Power Systems,Department of Thermal Engineering,Tsinghua-BP Clean Energy Center,Tsinghua University,Beijing 100084,China

出　　处：《Frontiers of physics》2012年第6期708-713,共6页物理学前沿（英文版）

基　　金：Acknowledgements The authors are grateful for the financial support from the National Natural Science Foundation of China （Grant No. 51061130536）.

摘　　要：Three major elements, carbon, hydrogen, and nitrogen, in twenty-four bituminous coal samples, were measured by laser-induced breakdown spectroscopy. Argon and helium were applied as ambient gas to enhance the signals and eliminate the interference of nitrogen from surrounding air. The relative standard deviation of the related emission lines and the performance in the partial least squares （PLS） modeling were compared for different ambient environments. The results showed that argon not only improved the intensity, but also reduced signal fluctuation. The PLS model also had the optimal performance in multi-element analysis using argon as ambient gas. The root mean square error of prediction of carbon concentration decreased from 4.25% in air to 3.49% in argon, while the average relative error reduced from 4.96% to 2.98%. Hydrogen line demonstrated similar improvement. Yet, the nitrogen lines were too weak to be detected even in an argon environment which suggested the nitrogen signal measured in air come from the breakdown of nitrogen molecules in the atmosphere.Three major elements, carbon, hydrogen, and nitrogen, in twenty-four bituminous coal samples, were measured by laser-induced breakdown spectroscopy. Argon and helium were applied as ambient gas to enhance the signals and eliminate the interference of nitrogen from surrounding air. The relative standard deviation of the related emission lines and the performance in the partial least squares （PLS） modeling were compared for different ambient environments. The results showed that argon not only improved the intensity, but also reduced signal fluctuation. The PLS model also had the optimal performance in multi-element analysis using argon as ambient gas. The root mean square error of prediction of carbon concentration decreased from 4.25% in air to 3.49% in argon, while the average relative error reduced from 4.96% to 2.98%. Hydrogen line demonstrated similar improvement. Yet, the nitrogen lines were too weak to be detected even in an argon environment which suggested the nitrogen signal measured in air come from the breakdown of nitrogen molecules in the atmosphere.

关 键 词：laser-induced breakdown spectroscopy （LIBS） ambient gas bituminous coal partial least squares （PLS） relative standard deviations （RSD） 

分 类 号：O433.54[机械工程—光学工程] TG142.33[理学—光学]