A plasma-image-assisted method for matrix effect correction in laser-induced breakdown spectroscopy

Deng Zhang; Yanwu Chu; Shixiang Ma; Siyu Zhang; Haohao Cui; Zhenlin Hu; Feng Chen; Ziqian Sheng; Lianbo Guo; Yongfeng Lu

doi:10.1016/j.aca.2020.02.003

A plasma-image-assisted method for matrix effect correction in laser-induced breakdown spectroscopy

Anal Chim Acta. 2020 Apr 22:1107:14-22. doi: 10.1016/j.aca.2020.02.003. Epub 2020 Feb 4.

Authors

Deng Zhang¹, Yanwu Chu¹, Shixiang Ma¹, Siyu Zhang¹, Haohao Cui¹, Zhenlin Hu¹, Feng Chen¹, Ziqian Sheng¹, Lianbo Guo², Yongfeng Lu³

Affiliations

¹ Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan, Hubei, 430074, PR China.
² Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan, Hubei, 430074, PR China. Electronic address: lbguo@hust.edu.cn.
³ Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, NE, 68588-0511, USA.

PMID: 32200888
DOI: 10.1016/j.aca.2020.02.003

Abstract

The matrix effect is one of the main bottlenecks for the laser-induced breakdown spectroscopy (LIBS) technique. In this work, image-assisted, laser-induced breakdown spectroscopy (IA-LIBS) based on the Lomakin-Scherbe formula was put forward as a correction to the matrix effect. The brightness and area information in the plasma image was extracted to correct the spectral line intensities among which the brightness information characterizes the plasma temperature, and the area information characterizes the ablative mass. To verify the feasibility of this method, the experiment was conducted on metal samples and pressed samples. The method was applied for quantitative analysis of copper (Cu), magnesium (Mg) in metal samples and chromium (Cr), manganese (Mn) in pressed samples. For the metal samples, after correcting the matrix effect by IA-LIBS, the determination coefficient R squared (R²) of Cu I 510.55 nm and Mg I 518.36 nm calibration curves were increased from 0.726 to 0.942 to 0.992 and 0.988, respectively. The root-mean-square-error of cross-validation (RMSECV) and the average relative error (ARE) decreased by 75.10% and 77.18%, respectively. For the pressed samples, R² of Cr I 520.84 nm and Mn I 403.07 nm calibration curves corrected by IA-LIBS increased from 0.364 to 0.098 to 0.975 and 0.980; and RMSECV and ARE decreased by 77.88% and 83.83%, respectively. The experimental results showed that IA-LIBS had an obvious improvement on elimination of the matrix effect for the different samples and the different elements. Therefore, IA-LIBS will become a promising technology and will greatly promote the development of LIBS in various fields.

Keywords: Laser-induced breakdown spectroscopy; Matrix effect; Plasma image.