Generation of macro- and microplastic databases by high-throughput FTIR analysis with microplate readers

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Fourier-transform infrared (FTIR) spectroscopy is the standard for plastic pollution analysis.
• Current high-throughput FTIR methods are limited for larger microplastics and macroplastics.
• Existing spectral libraries are inadequate for comprehensive material characterization.

Purpose of the Study:

• To develop a high-throughput FTIR technique for analyzing large plastic particles (> 500 µm).
• To create an extensive spectral reference database for plastic pollution research.
• To streamline the analysis of plastic debris using microplate readers.

Main Methods:

• Utilized FTIR microplate readers for analyzing particles > 500 µm.
• Developed a new reference database of over 6000 spectra (transmission, ATR, reflection) for 600+ materials.
• Designed a particle holder and a non-plastic microplate for efficient sample handling.
• Investigated the impact of particle thickness on spectral quality.

Main Results:

• Established a high-throughput method for large plastic particle analysis.
• Created a comprehensive spectral database relevant to plastic pollution.
• Demonstrated that thin particles yield better spectral quality and identification.
• Validated the database using Open Specy, identifying needs for more transmission and reflection data.

Conclusions:

• The new FTIR microplate reader technique enhances high-throughput analysis of large plastic debris.
• The expanded spectral database and optimized sample presentation improve plastic pollution characterization.
• Further development of spectral libraries, particularly for transmission and reflection modes, is recommended.