Feasibility Study on Quantification of Biodegradable Polyester Microplastics Based on Intrinsic Fluorescence.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Polymer Science

Background:

• Biodegradable plastics can fragment into microplastics, posing environmental risks.
• Efficient quantification methods for biodegradable microplastics (BMPs) are crucial for assessing ecological impact.

Purpose of the Study:

• To develop a label-free quantification method for BMPs using their intrinsic fluorescence.
• To investigate the relationship between fluorescence intensity and BMP concentration, size, and shape.

Main Methods:

• Utilized intrinsic fluorescence spectroscopy of biodegradable polyesters (PLA, PHB, PBS, PBAT, PCL).
• Investigated fluorescence emission originating from molecular functional groups and aggregated conjugated groups.
• Established linear models correlating PBAT mass concentration (100-500 mg/L) with fluorescence intensity at 436 nm and 465 nm under 380 nm excitation.

Main Results:

• Biodegradable microplastics exhibit characteristic fluorescence emissions.
• Fluorescence intensity is dependent on BMP size and shape.
• Achieved high correlation coefficients (R² = 0.877 and 0.963) for linear models of BMP quantification.
• The intrinsic fluorescence method showed comparable accuracy to fluorescence labeling but with simpler operation.

Conclusions:

• Intrinsic fluorescence offers a viable, label-free method for quantifying biodegradable microplastics.
• The developed method is simple and rapid, suitable for pre-isolated and purified microplastics.
• This approach aids in monitoring BMPs and understanding their environmental risks.