Study Suggests Laser-Induced XUV Spectroscopy Improves Precision and Detection Limits for Microanalysis

Researchers from Empa Materials Science and Technology in Switzerland and the University of Zurich have introduced laser-induced XUV spectroscopy (LIXS) as a new technique to improve the precision and detection limits of laser-induced breakdown spectroscopy (LIBS) for microanalysis of materials. The study is published in Spectrochimica Acta Part B: Atomic Spectroscopy (1).

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LIXS collects stable plasma emission in the extreme UV (XUV) that is associated with the early stages of laser plasma. Compared to LIBS, LIXS provides better precision and detection limits for determining light elements and halogens with high signal-to-noise (S/N) ratio and fractionation-free response. The information capacity of an XUV spectrometer is quadratically increased. The research team discusses specific electron-ion processes in the LIXS plasma, showing how it improves the precision and detection limits. The technique has potential applications in various fields such as materials science, mineralogy, biology, space, and remote geo-exploration. However, accurate and precise quantification still remains a challenge because of matrix effects and plasma-flicker noise.

LIBS has been widely used as an optical hyphenation technique for detecting the elemental fingerprint of a sample material through laser-induced plasma emission. Despite its effectiveness for rapid microanalysis, accurate and precise quantification remains a challenge due to matrix effects and plasma-flicker noise. In contrast, LIXS improves the detection limits and precision by collecting stable plasma emission in the XUV region associated with the early stages of the laser-plasma. The team demonstrates that the information capacity of an XUV spectrometer is quadratically increased compared to LIBS. The study also discusses specific electron-ion processes in the LIXS plasma, which contribute to improving the precision and detection limits. The new technique has potential applications in various fields such as materials science, mineralogy, biology, space, and remote geo-exploration.

LIXS works similarly to LIBS, but it collects the stable plasma emission in the XUV. LIXS uses a double-pulse approach, which consists of one short-wavelength pulse to ablate the sample and a second infrared pulse to excite the vapor. The stable plasma emission in the XUV region is associated with the early stages of the laser plasma. The emitted radiation is dispersed by a grating and then detected by a charge-coupled device (CCD) camera to provide high-resolution spectra that can reveal the elemental composition of the sample. Specific electron-ion processes in the LIXS plasma improve the limits of detection and the precision, allowing for the detection of light elements and halogens with high signal-to-noise ratio and fractionation-free response.

The study highlights that LIXS' strength is its ability to determine light elements and halogens with high signal-to-noise ratio and fractionation-free response. However, accurate and precise quantification still remains a challenge because of matrix effects and plasma-flicker noise. The team suggests that further research is needed to overcome these challenges and establish LIXS as a reliable microanalytical technique.

Overall, the study shows that LIXS is a promising technique for improving the precision and detection limits of LIBS for microanalysis of materials. It offers potential benefits for a wide range of fields, but further research is needed to overcome existing challenges.

Reference

(1) Bleiner, D.; Qu, D.; Kraft, K.; Shlyakhtun, O. Laser-induced XUV spectroscopy (LIXS): From fundamentals to application for high-precision LIBS. Spectrochimica Acta Part B: At. Spectrosc. 2023, 204, 106668. DOI: 10.1016/j.sab.2023.106668