Identification and Quantification of Microplastics Using Nile Red Staining

Plastic is a very useful and versatile product, however extensive use and unchecked disposal has resulted in significant global impacts. Microplastic (0.1 µm–5 mm) is particularly problematic and is a widespread pollutant impacting aquatic ecosystems. The accumulation of microplastics produces negative repercussions such as aesthetic and economic impact and most importantly adverse biological and ecological effects. Existing identification and quantification techniques such as Raman spectroscopy, Pyrolysis-gas chromatography with mass spectrometry and FT-IR spectroscopy are time consuming and require expensive instruments. The aim of this research is to develop a rapid fluorescent staining procedure for microplastic quantification using a fluorescent dye, Nile Red. Developing a fluorescent staining procedure will provide a rapid way of differentiating microplastics from the other natural materials, enabling easier and more accurate quantification of microplastics. The first step would be the formation of microplastics from common materials such as freezer bags (polyethylene), bottle caps (polypropylene) or food containers (polystyrene). These will be used as standards for further tests including the selection of a suitable organic solvent that would not degrade or stain the filter paper but effectively stain the microplastics. Stained microplastics will be irradiated with blue or green light causing fluorescence, which can then be detected using red filter. This method will be compared to traditional methods such as Raman spectroscopy and brightfield microscopy and then be applied to the samples extracted from the North Saskatchewan River. The results from the study will help in efficient sample processing and understanding microplastic contamination in our environment. Faculty Mentor: Dr. Matthew Ross Discipline: Chemistry