Journal of Emerging Scholarship

With the rapid increase in microplastic (MP) documentation worldwide, techniques for detection have increased but are often costly. The focuses of this study were (1) to develop an accessible and cost-effective method to detect MP using Nile Red (NR) stain and a low-tech fluorescence microscope (FM) assembly, and (2) to quantify and identify MP collected from a local beach using Fourier-transform infrared spectroscopy (FTIR). We tested NR’s capacity to stain five types of plastics in three solvents of varying polarity (hexane, toluene, and ethanol) at 1mg/1ml; plastics stained with NR in toluene fluoresced with greatest intensity. We assessed the effect of plastic color on fluorescence by staining different colored pellets; black pellets fluoresced the least compared to red and yellow. Aging plastics in water over 7 days showed decreased fluorescence intensity compared to pristine plastics, indicating potential underestimation of black and previously weathered MP in environmental samples. Sand samples from Ft. Smallwood Park beach (Pasadena, MD) contained higher concentrations of MP (2-5mm) further away from the water line. FTIR analysis identified polyethylene (46.7%) and polypropylene (22.2%) to be the most abundant plastic polymers.