Developing ToF-SIMS methods for investigating the degradation of plastic debris on beaches

Plastic debris in the Earth's oceans and larger freshwater (FW) bodies presents a serious environmental threat to aquatic organisms. Degradation of plastic by mechanical erosion and chemical weathering is minimal in water. Once deposited on beaches, plastic fragments are exposed to UV radiation and physical processes controlled by winds, currents and waves. Recent work([1]) has indicated that saltwater (SW) beach plastics feature both mechanically and chemically weathered surface textures, wherein mechanically weakened fractures are the sites of granular oxidation textures. Analysis of lacustrine (FW) beach plastics is now ongoing, and shows similar textural effects of mechanical and chemical weathering. TOF-SIMS, with its high spatial resolution and ability to detect molecular species, is ideally suited to explore chemical changes and oxidative processes occurring in these plastics. The method enables detection of low levels of absorbed species present in oxidized polymeric materials.([2]) TOF-SIMS analysis is currently being conducted to investigate the oxidation process in polyethylene beach plastics from both SW(Kauai, HI, USA) and FW (Lake Huron, ON, Canada) beaches. Copyright (C) 2010 John Wiley & Sons, Ltd.