The LIBS Challenge
Laser-induced breakdown spectroscopy has both advantages and disadvantages. LIBS offers rapid measurements of multiple atomic elements simultaneously in a single scan. It requires less sample preparation than other methods and with the use of fiber optics, can be deployed from a distance or used to sample on a very small scale. Even with its benefits, there have been obstacles to wider LIBS adoption.
First, the advantage of being able to perform measurements at a distance is especially useful for measurements in hostile environments, but those same environments offer ambient conditions that are less than ideal. Airborne particulates, condensation, and temperature fluctuations can impede a LIBS system’s ability to capture spectral data and distinguish it from background noise.
Hardening instruments to ambient conditions is crucial in LIBS measurements where, for example, low-light conditions would be adversely affected by thermal instability. Adjusting focal length, selecting ideal wavelength regions, and processing out matrix effects are variables that can drastically change measurement parameters. LIBS generally requires a robust set of matrix-matched samples to develop a calibration model which can support qualitative and quantitative measurements. These standards may or may not exist and require validation using more traditional methods of testing such as ICP MS.
In spite of these challenges, however, LIBS is beginning to make steady progress in select industries.
LIBS Industrial Success Stories
Geochemistry & Ore/Mineral Extraction
Laser-induced breakdown spectroscopy is gaining a foothold in mining, mineral extraction, and metallurgy with a large body of research supporting the development of reference calibration data, and in turn leading to increased adoption for industrial applications.
LIBS can be applied throughout the ore extraction and processing industries. Monitoring metallurgical processes involves the measurement of plasma created at the surface of molten metals, inline systems that monitor raw ore composition in preprocessing, and quality management testing the composition of alloys in finished ingots.
LIBS can also be deployed in energy production. Coal-fired power generation requires precisely calibrated fuel mixtures to run most efficiently. Coal is monitored for ash content and other constituents before entering the plant combustion zone. Adjusting the fuel mix helps plants prevent slagging and reduces greenhouse gas emissions.
Laser-induced Breakdown Spectroscopy is at work in the recycling industry, too. Plastics and Metals can be more easily separated using the rapid material identification capabilities of a LIBS system. In aluminum recycling, LIBS allows faster and more accurate sorting of scrap metal, because it can differentiate alloys in the same family. The recycling relies heavily on handheld LIBS instruments.
Standard LIBS Solutions
LIBS applications defy standard solutions because each application requires a unique measurement methodology. Laser-induced breakdown spectroscopy can offer robust solutions for industry, but there is no one-size-fits-all off the shelf solution that will work for every application. Easily customizable modular solutions can open the door to LIBS industrialization.
Identifying relevant spectral ranges and overcoming ambient conditions, are the first considerations when designing a LIBS system. While multivariate elemental analysis is possible, the wavelength data may require multiple detector channels to adequately cover the ranges of absorption lines and spectral peaks in question.
Even when reference calibration curves are available, bringing an industrial-suited solution to market requires expertise and dedication to finding the right solution. Work with a partner that can help you navigate the challenges. Call your Avantes Sales Engineer today.
Campanella, B., et al. "Classification of wrought aluminum alloys by ANN evaluation of LIBS spectra from aluminum scrap samples." Spectrochimica Acta Part B: Atomic Spectroscopy(2017). https://www.avantes.com/images/Whitepapers/3._Classification_of_wrought_aluminum_alloys_by_ANN_evaluation_of_LIBS_spectra_from_aluminum_scrap_samples.pdf
Li, Jie, et al. "Effects of experimental parameters on elemental analysis of coal by laser-induced breakdown spectroscopy." Optics & Laser Technology 41.8 (2009): 907-913. https://orbi.ulg.ac.be/bitstream/2268/145058/1/Effects%20of%20experimental%20parameters%20on%20elemental%20analysis%20of%20coal%20by%20laser-induced%20breakdown%20spectroscopy.pdf
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Xia, H., and M. C. M. Bakker. "Online sensor system based on laser-induced breakdown spectroscopy in quality inspection of demolition concrete." 27th International Conference on Solid Waste Technology and Management, Philadelphia, USA 11-14 maart 2012. International Society for Industrial Ecology, 2012. https://repository.tudelft.nl/islandora/object/uuid:73f5290f-1563-45b3-9dd2-023cd7598947/datastream/OBJ