Researchers from Marburg University (Marburg, Germany) have shown a promising alternative for the spectroscopic detection of microplastics. The pollution with microplastics is becoming an alerting environmental problem. Microplastics are commonly defined as plastic particles with diameters below 5 mm. The particles enter the environment directly as small particles from cleaning and cosmetic products or as bigger pieces of plastic litter that gradually degrade into smaller and smaller pieces. Typically, plastic particles are identified using FTIR or Raman spectroscopy.
The researchers from Marburg have shown that photoluminescence spectroscopy could be a cost-effective alternative for microplastics detection. Using a blue laser they have investigated a set of nine bulk plastic samples and nine samples of natural materials typically found in the marine environment. Although these materials are not known to be good light emitters they show photoluminescence when excited with short-wavelength light. The photoluminescence spectra look structureless and look similar at the first glance. Yet, a detailed analysis allows for a distinction between the different materials.
“Our results look promising and represent the first step towards microplastic detection using photoluminescence. Yet, a tremendous amount of work lies ahead of us if we aim for an automated technique,” says professor Martin Koch, head of the research group at Marburg University.
Details of the work are published in Applied Physics; see J. Ornik et al., Applied Physics B 126, 15 (2020).
SOURCE: Marburg University; https://www.researchgate.net/publication/338026456_Could_photoluminescence_spectroscopy_be_an_alternative_technique_for_the_detection_of_microplastics_First_experiments_using_a_405_nm_laser_for_excitation