Laser-induced breakdown spectroscopy (LIBS) is a spectrometry technique for the material components analysis with advantages of rapid, in situ, real-time, remote analysis and simple sample preparation. Atomic emission, generally used in conventional LIBS, still has several drawbacks. To overcome these flaws, researchers have been focusing on molecular emission in recent years, but the weak spectra of molecular emission has made the quantitative accuracy and sensitivity deterioration.
The research group of Wuhan National Laboratory for Optoelectronics introduced laser-induced radical fluorescence for molecular emission enhancement. Two types of boron monoxide (BO) radical excitations, vibrational ground state excitation (LIRFG) and vibrational excited state excitation (LIRFE), were compared. The results showed that these two radical excitations were both capable of enhancing the molecular spectra and improving the quantitative performance of boron determination. In addition, through the comparison of the two excitations, it was determined that the LIRFG had better sensitivity, with an LoD of 0.0993 wt.%, while the LIRFE was more accurate, with a RMSECV of 0.2514 wt.%. This work resulted in a new way to enhance the spectra and improve the determination of molecular emission with LIBS-LIRF.
This work has been published in Optics Express(L.B. Guo, Z.H. Zhu, J.M. Li, Y. Tang, S.S Tang, Z.Q. Hao, X.Y. Li, Y.F. Lu, and X.Y. Zeng, "Determination of boron with molecular emission using laser-induced breakdown spectroscopy combined with laser-induced radical fluorescence," Opt. Express 26, 2634-2642 (2018)).
The research was financially supported by National Natural Science Foundation of China (No.51429501 and 61575073) and China Postdoctoral Science Foundation (No.2017M622415).
Fig.1. Boron LIBS-LIRF principle (a) and spectral enhancement (b).
