Improvement in detection reproducibility of laser-induced breakdown spectroscopy based on plasma acoustic correction

Abstract

To reduce the uncertainty and improve the long-term reproducibility of laser-induced breakdown spectroscopy (LIBS) quantitative analysis, an acoustic correction (AC) method is proposed for LIBS detection. A simultaneous acquisition system for laser-induced plasma spectroscopy and the acoustic signal was used to analyse Cr, Mo, Ni, and V elements in alloy steels, and the improvement of the AC method on the spectral uncertainty, calibration model, and long-term reproducibility was investigated. The results show that, compared to calibration curves with the original spectral intensity, the average relative standard deviation (ARSD) of the spectral intensities of the four elements decreased by 26.7%, the average coefficient of determination (R²) of the calibration curves was improved from 0.978 to 0.992, the average relative error (ARE) for the long-term in 48 hours decreased by 38.6%, and the ARSD of the spectra in eight days was significantly reduced by 43.1%. Thus, the use of the AC method can significantly reduce the uncertainty of the spectral signal, improve the robustness of the calibration model, and effectively improve the long-term reproducibility of the quantitative analysis of LIBS.