RAMAN Imaging & Microplastics Analysis Facility

Microplastics (MPs) are operationally defined as particles of any type of plastic, less than 5 mm (0.20 in) in diameter (NOAA). Most MPs are derived from fragmentation of larger plastic products, such as food and beverage packaging, clothing, and a myriad of manufactured consumer products. Some MPs are intentionally manufactured, such as abrasives used in personal care and industrial polishing products. MPs are contaminants that enter natural ecosystems from a variety of sources and their global distributions, concentrations, transport, degradation, and ecological consequences are all poorly understood. MPs are thought to act as carriers of other types of adsorbed contaminants, including carcinogens, and enter food webs near their base. A major impediment to understanding MP dynamics and their ecological consequences is unequivocal recognition and quantification of plastic polymers in environmental samples. Microscopically, MPs can resemble some types of mineral and biological particles, routinely leading to misidentification. One of the few technologies that can recognize MPs as small as about 0.5 um and reliably identify the actual polymer is Confocal Raman Microspectroscopy (CRM). CRM interrogates samples by laser light through an automated microscope and collects spectroscopic data that have been referred to as “molecular fingerprints”. Each plastic polymer type has a distinctive and easily recognized Raman spectrum. Techniques developed Stony Brook University’s NAno-Raman Molecular Imaging Laboratory (NARMIL) have enabled unique environmental surveys to identify the polymers in truly microscopic plastic particles, smaller than 100 um. NARMIL’s technology also provides size and shape analysis of each MP particle. Combining these data permits construction of inventories of each polymer and attempt source assessments.