摘要
Improvement of measurement precision and repeatability is one of the issues currently faced by the laser-induced breakdown spectroscopy （LIBS） technique, which is expected to be capable of precise and accurate quantitative analysis. It was found that there was great potential to improve the signal quality and repeatability by reducing the laser beam divergence angle using a suitable beam expander （BE）. In the present work, the influences of several experimental parameters for the case with BE are studied in order to optimize the analytical performances： the signal to noise ratio （SNR） and the relative standard deviation （RSD）. We demonstrate that by selecting the optimal experimental parameters, the BE-included LIBS setup can give higher SNR and lower RSD values of the line intensity normalized by the whole spectrum area. For validation purposes, support vector machine （SVM） regression combined with principal component analysis （PCA） was used to establish a calibration model to realize the quantitative analysis of the ash content. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The measurement accuracy presented here for ash content analysis is estimated to be 0.31%, while the average relative error is 2.36%.
Improvement of measurement precision and repeatability is one of the issues currently faced by the laser-induced breakdown spectroscopy （LIBS） technique, which is expected to be capable of precise and accurate quantitative analysis. It was found that there was great potential to improve the signal quality and repeatability by reducing the laser beam divergence angle using a suitable beam expander （BE）. In the present work, the influences of several experimental parameters for the case with BE are studied in order to optimize the analytical performances： the signal to noise ratio （SNR） and the relative standard deviation （RSD）. We demonstrate that by selecting the optimal experimental parameters, the BE-included LIBS setup can give higher SNR and lower RSD values of the line intensity normalized by the whole spectrum area. For validation purposes, support vector machine （SVM） regression combined with principal component analysis （PCA） was used to establish a calibration model to realize the quantitative analysis of the ash content. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The measurement accuracy presented here for ash content analysis is estimated to be 0.31%, while the average relative error is 2.36%.
基金
supported by the 973 Program of China(No.2012CB921603)
National Natural Science Foundation of China(Nos.61475093,61127017,61178009,61108030,61378047,61275213,61475093,and 61205216)
the National Key Technology R&D Program of China(No.2013BAC14B01)
the Shanxi Natural Science Foundation(Nos.2013021004-1 and 2012021022-1)
the Shanxi Scholarship Council of China(Nos.2013-011 and 2013-01)
the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi,China
作者简介
E-mail address of corresponding author ZHANG Lei： k1226@sxu.edu.cn
