Fluorescence Signatures of Dissolved Organic Matter Leached from Microplastics: Polymers and Additives.

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Polymer Science

Background:

• Microplastic pollution is a global concern, yet the dissolved organic matter (DOM) released from plastics remains understudied.
• Understanding the characteristics of plastic-derived DOM is crucial for assessing its environmental impact.

Purpose of the Study:

• To investigate the fluorescence signatures of DOM leached from common plastic materials and additives.
• To identify and characterize fluorescent components within plastic-derived DOM.
• To explore the potential of fluorescence as a proxy for plastic-derived DOM.

Main Methods:

• Excitation Emission Matrix-Parallel Factor Analysis (EEM-PARAFAC) was employed to analyze DOM.
• Common polymers (PVC, PS) and additives (DEHP, BPA) were exposed to UV light to induce DOM leaching.
• Leached DOM was quantified by dissolved organic carbon and fluorescence intensity.

Main Results:

• Four distinct fluorescent components were identified: three protein/phenol-like (C1, C3, C4) and one humic-like (C2).
• Component C4 showed a strong correlation with DOM leached from Bisphenol A (BPA) and BPA-containing plastics.
• Components C2 and C4 correlated with DOM leached from polymers under UV light.

Conclusions:

• Plastic materials and additives leach DOM into the environment, possessing distinct fluorescent characteristics.
• Fluorescence analysis, particularly component C4, can serve as a proxy for identifying DOM derived from BPA and related plastics.
• This research underscores the importance of characterizing plastic-derived DOM for a comprehensive understanding of plastic pollution in aquatic ecosystems.