Laser-induced breakdown spectroscopy(LIBS)has been used for soil analysis,but its measurement accuracy is often influenced by matrix effects of different kinds of soils.In this work,a method for matrix effect suppress...Laser-induced breakdown spectroscopy(LIBS)has been used for soil analysis,but its measurement accuracy is often influenced by matrix effects of different kinds of soils.In this work,a method for matrix effect suppressing was developed using laser-induced plasma acoustic signals to correct the original spectrum,thereby improving the analysis accuracy of the soil elements.A good linear relationship was investigated firstly between the original spectral intensity and the acoustic signals.The relative standard deviations(RSDs)of Mg,Ca,Sr,and Ba elements were then calculated for both the original spectrum and the spectrum with the acoustic correction,and the RSDs were significantly reduced with the acoustic correction.Finally,calibration curves of MgⅠ285.213 nm,CaⅠ422.673 nm,SrⅠ460.733 nm and BaⅡ455.403 nm were established to assess the analytical performance of the proposed acoustic correction method.The values of the determination coefficient(R~2)of the calibration curves for Mg,Ca,Sr,and Ba elements,corrected by the acoustic amplitude,are improved from 0.9845,0.9588,0.6165,and 0.6490 to 0.9876,0.9677,0.8768,and 0.8209,respectively.The values of R~2 of the calibration curves corrected by the acoustic energy are further improved to 0.9917,0.9827,0.8835,and 0.8694,respectively.These results suggest that the matrix effect of LIBS on soils can be clearly improved by using acoustic correction,and acoustic energy correction works more efficiently than acoustic amplitude correction.This work provides a simple and efficient method for correcting matrix effects in the element analysis of soils by acoustic signals.展开更多
Spatial confinement is a simple and cost-effective method for enhancing signal intensity and improving the detection sensitivity of laser-induced breakdown spectroscopy(LIBS).However,the spatial confinement effects of...Spatial confinement is a simple and cost-effective method for enhancing signal intensity and improving the detection sensitivity of laser-induced breakdown spectroscopy(LIBS).However,the spatial confinement effects of LIBS under different pressures remains a question to be studied,because the pressure of the ambient gas has a significant influence on the temporal and spatial evolution of plasma.In this study,spatial confinement effects of LIBS under a series of reduced air pressures were investigated experimentally,and the plasma characteristics under different air pressures were studied.The results show that the reduced air pressure can lead to both earlier onset and weakening of the enhancement effect of the spatial confinement on the LIBS line intensity.When the air pressure drops to 0.1 kPa,the enhancement effect of the emission intensity no longer comes from the compression of the reflected shock wave on the plasma,but from the cavity’s restriction of the plasma expansion space.In conclusion,the enhancement effect of spatial confinement technology on the LIBS is still effective when the pressure is reduced,which further expands the research and application field of spatial confinement technology.展开更多
基金financially supported by National Natural Science Foundation of China(No.12064029)by Jiangxi Provincial Natural Science Foundation(No.20202BABL202024)by the Open project program of Key Laboratory of Opto-Electronic Information Science and Technology of Jiangxi Province(No.ED202208094)。
文摘Laser-induced breakdown spectroscopy(LIBS)has been used for soil analysis,but its measurement accuracy is often influenced by matrix effects of different kinds of soils.In this work,a method for matrix effect suppressing was developed using laser-induced plasma acoustic signals to correct the original spectrum,thereby improving the analysis accuracy of the soil elements.A good linear relationship was investigated firstly between the original spectral intensity and the acoustic signals.The relative standard deviations(RSDs)of Mg,Ca,Sr,and Ba elements were then calculated for both the original spectrum and the spectrum with the acoustic correction,and the RSDs were significantly reduced with the acoustic correction.Finally,calibration curves of MgⅠ285.213 nm,CaⅠ422.673 nm,SrⅠ460.733 nm and BaⅡ455.403 nm were established to assess the analytical performance of the proposed acoustic correction method.The values of the determination coefficient(R~2)of the calibration curves for Mg,Ca,Sr,and Ba elements,corrected by the acoustic amplitude,are improved from 0.9845,0.9588,0.6165,and 0.6490 to 0.9876,0.9677,0.8768,and 0.8209,respectively.The values of R~2 of the calibration curves corrected by the acoustic energy are further improved to 0.9917,0.9827,0.8835,and 0.8694,respectively.These results suggest that the matrix effect of LIBS on soils can be clearly improved by using acoustic correction,and acoustic energy correction works more efficiently than acoustic amplitude correction.This work provides a simple and efficient method for correcting matrix effects in the element analysis of soils by acoustic signals.
基金This research was financially supported by the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2018WNLOKF002)the National Natural Science Foundation of China(Grant Nos.12064029 and 61865013)+1 种基金Jiangxi Provincial Natural Science Foundation(No.20202BABL202024)Ph.D.Research Startup Foundation of Nanchang Hangkong University(No.EA201808384).
文摘Spatial confinement is a simple and cost-effective method for enhancing signal intensity and improving the detection sensitivity of laser-induced breakdown spectroscopy(LIBS).However,the spatial confinement effects of LIBS under different pressures remains a question to be studied,because the pressure of the ambient gas has a significant influence on the temporal and spatial evolution of plasma.In this study,spatial confinement effects of LIBS under a series of reduced air pressures were investigated experimentally,and the plasma characteristics under different air pressures were studied.The results show that the reduced air pressure can lead to both earlier onset and weakening of the enhancement effect of the spatial confinement on the LIBS line intensity.When the air pressure drops to 0.1 kPa,the enhancement effect of the emission intensity no longer comes from the compression of the reflected shock wave on the plasma,but from the cavity’s restriction of the plasma expansion space.In conclusion,the enhancement effect of spatial confinement technology on the LIBS is still effective when the pressure is reduced,which further expands the research and application field of spatial confinement technology.
