Sampling of microplastics at a materials recovery facility.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Detecting airborne microplastics is challenging due to instrumental and sample preparation limitations.
• Assessing the environmental risks of microplastics requires accurate measurement in real-world conditions.
• Existing methods struggle with the complexity of airborne particulate matter.

Purpose of the Study:

• To develop and validate a methodology for sampling and characterizing airborne microplastics.
• To overcome instrumental constraints in microplastic analysis.
• To enable better risk assessment of airborne microplastics.

Main Methods:

• Particulate sampling at a materials recovery facility using Nucleopore filters.
• Filter preparation with aluminum coating and laser-engraved fiducial patterns for micro-Raman spectroscopy.
• Multi-platform microscopy including scanning electron microscopy (SEM) and light microscopy (LM).
• Analysis of carbon-rich and colored particles using micro-Raman spectroscopy for polymer identification.

Main Results:

• Optimized sampling conditions determined as 2 hours at 25 L/min.
• Fiducial patterns facilitated sample identification and particle relocation for orthogonal measurements.
• SEM and LM identified carbon-rich and colored particles, respectively.
• Micro-Raman spectroscopy successfully identified specific polymers within airborne particles.

Conclusions:

• The developed methodology enables effective sampling and characterization of airborne microplastics.
• This approach addresses key challenges in analyzing microplastics in environmental samples.
• The study provides a foundation for more accurate risk assessment of airborne microplastics.