Magnetic Levitation (MagLev) to Isolate and Evaluate Micron-sized Particles In the Russian River

Presenter: Camila Carrillo

Presenter Status: Undergraduate student

Academic Year: 22-23

Semester: Spring

Department: Chemistry

Funding Source/Sponsor: CEI

Abstract:
Microplastics pose a threat to human health and ecosystem sustainability. Current methods for distinguishing microplastics rely on density-based techniques that can be time-consuming to prepare. These include the sink-float method and developing a sucrose density gradient. The sink-float method separates particles into two groups using a solution of known density, where the density of the solution must be adjusted for each measurement. A second method for distinguishing particles based on density is through the use of a sucrose density gradient where particles settle in a solution with a similar density. The gradient is meticulously prepared by the layering of different concentrations of sucrose in water. Caution has to be taken so that the contents do not blend together at their interfaces. Magnetic levitation (MagLev) can be used to isolate and analyze diamagnetic particles based on differences in their densities. The diamagnetic analyte is placed in a paramagnetic solution and positioned between two neodymium magnets. The solution in the presence of the magnetic field creates a continuous density gradient whose range can be adjusted. Thus far, we have collected samples near the confluence of the Dry Creek watershed and the Russian River. Fluorescence microscopy reveals bead-like structures from the use of a dye that preferentially binds to synthetic polymers. While this suggests the presence of microplastics, further analysis is necessary to confirm their identities. We hope to reveal the identities of the particles by their separation and isolation in MagLev.