Quantification Challenges in Polymer Analysis in Urban Runoff and Wastewater using Pressurized Liquid Extraction and...

Area of Science:

• Environmental Science
• Analytical Chemistry
• Polymer Science

Background:

• Microplastics (MPs) are pervasive environmental pollutants.
• Assessing MP contamination in water requires reliable analytical methods.
• Potential risks to ecosystems and human health necessitate accurate quantification.

Purpose of the Study:

• To optimize methods for isolating and quantifying four common microplastics (polyethylene, PET, polypropylene, polystyrene) in water and wastewater.
• To enhance the reliability and sensitivity of microplastic analysis in diverse water matrices.
• To establish a robust protocol for routine environmental monitoring of microplastic pollution.

Main Methods:

• Pressurized liquid extraction (PLE) combined with pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS).
• A two-step PLE protocol involving methanol and tetrahydrofuran (THF) at optimized temperatures (100°C and 180°C).
• Optimization of Py-GC/MS conditions (625°C for 40s) and calibration strategies (solubilized vs. solid standards).

Main Results:

• Achieved microplastic recoveries ranging from 43-58% using the optimized two-step PLE method.
• Polyethylene (PE) and polyethylene terephthalate (PET) were dominant in wastewater samples, with concentrations up to 749.0 ± 200.0 μg/L (PE) and 56.7 ± 22.6 μg/L (PET).
• Polypropylene (PP) and polystyrene (PS) were detected at lower levels (PP: 8.2–16.9 μg/L; PS: 2.2–8.4 μg/L).

Conclusions:

• The optimized PLE and Py-GC/MS method improves microplastic detection in various water types.
• Method parameters, including isolation, pyrolysis, and calibration, significantly impact analytical reliability.
• The study provides a reliable approach for routine environmental monitoring, highlighting the need for further protocol refinement and standardization.