MBNMS
Microplastic monitoring
Identifying microplastics in water samples
Microplastic contamination of the ocean is a growing environmental concern. In collaboration with Amelia Labbe (Cal State University, Monterey Bay) and Lisa Uttal (NOAA), we have developed methods to detect microplastics in seawater samples with a simple microscope. Microplastics were identified using fluorescence and polarization microscopy ( see also MBNMS plankton page). This photo shows control fragments stained with the fluorescent Nile Red dye. CA = cellulose acetate from a cigarette filter, N = nylon fishing line, PLA = polylactic acid from compostable plastic and PE = polyethylene from a plastic bottle.
Many plastic appear bright under crossed polarizers and show color fringes due to their birefringence such as this fragment from a polythene bag
Most plastics are hydrophobic and fluoresce when stained with Nile Red. This polythene bag fragment emits yellow light, whereas more hydrophilic plastics fluoresce in the red
Cigarette butt filters contain a plastic made from cellulose acetate which readily takes up the Nile Red dye.
Seawater samples from the Monterey Bay contain microplastics which stain with Nile Red.
This work was published in the Journal of Chemical Education, where it was featured on the front cover.
The procedures we use are outlined in some YouTube videos
Poster presented at the 2020 California Cooperative Oceanic Fisheries Investigations (CalCOFI) conference
CalCOFI_Poster_bagshaw.pptx