Joseph A Gardella oral presentation (OA2-Mon4-3-1)
Surface Chemistry of Microplastics in the Freshwater Environment: ToF-SIMS Studies
Dept. of Chemistry - University at Buffalo, SUNY, 470 NSC, NY 14216 Buffalo, United States
The ubiquity of microplastics pollution in seawater (1) and freshwater (2) is of growing interest in environmental science. As the largest source of surface fresh water in the world, the Laurentian Great Lakes in the US are an important place to study the potential of these particles becoming pollutants and a transport medium of further pollution, specifically if they are also adsorbing potentially toxic chemicals to their surfaces (3). Chemical degradation (hydrolysis, oxidation and surface adsorption of chemicals (3) are known as impacts that affect the health impact on fish and plants.
No peer reviewed publications have reported the use of modern surface science measurements to identify adsorbed species on marine or freshwater microplastics. The goal of this research is to use time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray Photoelectron Spectrometry (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) to characterize and examine the surfaces of microplastics taken from the Great Lakes for evidence of degradation and of adsorbed chemical pollutants. From ToFSIMS analysis of the surfaces of a variety of microplastics (polyethylene, polypropylene, polystyrene, nylon, polyethylene terephthalate, polymethyl methacrylate, polyurethane, etc.) detected the presence of contamination from siloxane polymers, such as SiliconesTM and fluorocarbons, especially perfluorooctane surfactants, such as perfluorooctanoic acid (PFOA) (Fig 1). These surfactants and polymers are adsorbing to the surfaces of these microplastics due to the hydrophobicity of both the plastics and the chemicals of interest.