A smartphone label-free and automated thermo-analytical method based on image analysis to detect microplastics

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Microplastics (MPs) are ubiquitous environmental pollutants found in various ecosystems, including continental waters and coastlines.
• Growing concerns exist regarding MPs' potential harm to wildlife, entry into food chains, and human health implications.
• There is a critical need for simple, automated analytical systems to assess MP contamination levels.

Purpose of the Study:

• To develop a low-cost, automated analytical method for identifying, counting, and sizing microplastics.
• To differentiate microplastics from non-plastic particles using image-based analysis and thermal properties.
• To provide a rapid screening tool for assessing environmental microplastic contamination.

Main Methods:

• Utilized a smartphone camera and a dedicated algorithm for image-based analysis.
• Employed a heating ramp (25-220 °C) to observe melting and size changes in particles.
• Analyzed semi-crystalline and amorphous microplastics, including polyethylene, polypropylene, and polystyrene.

Main Results:

• Successfully identified, counted, and sized microplastics in under 5 minutes.
• Differentiated microplastics from non-plastic particles based on their thermal behavior (melting/size change).
• Validated the method on spiked soil and sand samples, as well as real environmental samples with positive outcomes.

Conclusions:

• The developed method offers a rapid, cost-effective, and automated solution for microplastic analysis.
• This technique can significantly aid in the initial assessment of microplastic contamination in environmental samples.
• The approach facilitates large-scale screening, supporting further investigation into the ecological and health risks posed by microplastics.