Detection and estimation of a microplastic particle size by laser-based spectroscopy techniques

presentation, poster

en

Microplastic pollution is a growing concern in the modern world due to its ubiquitous nature and potential harm to the environment and human health. These tiny plastic particles, measuring less than 5 millimeters in size, are generated from a variety of sources, including plastic packaging, cosmetics, and industrial waste. They accumulate in oceans, freshwater bodies, and soil, posing a serious threat to marine life, wildlife, and human health. Detection of the microplastic particles in various environments rapidly and reliably can improve the chances of preventing the microplastic pollution. To present a potential of using laser-based spectroscopy techniques for this application, we have chosen Laser-Induced Breakdown Spectroscopy and Raman spectroscopy. It was already proven in several papers, that detection of microplastic particles by LIBS and Raman spectroscopy is possible. In this work we focused on polyethylene particles as PE is the most common polymer type in the world and the danger of PE particles entering fragile ecosystems is high. This work shows, that the PE microplastic particles are detectable by both selected techniques. In addition, we show, that the changes in size of the particle can be correlated to signal changes in both techniques and thus a size calibration can be formed. This calibration was made for particles sizing from 250 μm down to 1 μm. The work shows successful PE particle identification by both LIBS and Raman spectroscopy as well as a particle size estimation by changes in spectral response. Both spectroscopy methods were able to discriminate the polymer signal from other accompanying signals. As the particle size gets below the spot size of the LIBS technique a combination of spectral responses occur. The combination of background (epoxy) and microplastic particle signals can be deconvoluted to be processed separately.

Microplastic pollution is a growing concern in the modern world due to its ubiquitous nature and potential harm to the environment and human health. These tiny plastic particles, measuring less than 5 millimeters in size, are generated from a variety of sources, including plastic packaging, cosmetics, and industrial waste. They accumulate in oceans, freshwater bodies, and soil, posing a serious threat to marine life, wildlife, and human health. Detection of the microplastic particles in various environments rapidly and reliably can improve the chances of preventing the microplastic pollution. To present a potential of using laser-based spectroscopy techniques for this application, we have chosen Laser-Induced Breakdown Spectroscopy and Raman spectroscopy. It was already proven in several papers, that detection of microplastic particles by LIBS and Raman spectroscopy is possible. In this work we focused on polyethylene particles as PE is the most common polymer type in the world and the danger of PE particles entering fragile ecosystems is high. This work shows, that the PE microplastic particles are detectable by both selected techniques. In addition, we show, that the changes in size of the particle can be correlated to signal changes in both techniques and thus a size calibration can be formed. This calibration was made for particles sizing from 250 μm down to 1 μm. The work shows successful PE particle identification by both LIBS and Raman spectroscopy as well as a particle size estimation by changes in spectral response. Both spectroscopy methods were able to discriminate the polymer signal from other accompanying signals. As the particle size gets below the spot size of the LIBS technique a combination of spectral responses occur. The combination of background (epoxy) and microplastic particle signals can be deconvoluted to be processed separately.

Laser-induced breakdown spectroscopy; Raman spectroscopy; Microplastics; Polyethylene; Principal Component Analysis

05.09.2023

Porto, Portugalsko

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