Quantification of polyethylene terephthalate microplastics and nanoplastics in sands, indoor dust and sludge using a...

Area of Science:

• Environmental Science
• Analytical Chemistry
• Polymer Science

Background:

• Microplastics, particularly polyethylene terephthalate (PET), are pervasive environmental contaminants.
• Accurate quantification of PET microplastics and nanoplastics (PET MNPs) in diverse matrices is crucial for risk assessment.
• Existing methods for PET MNP analysis can be complex and time-consuming.

Purpose of the Study:

• To develop and validate an effective 3-step method for quantifying PET MNPs in complex environmental matrices.
• To establish the method's performance, including recovery rates and limits of quantification.
• To apply the developed method to real-world environmental samples such as beach sand, indoor dust, and sewage sludge.

Main Methods:

• A simplified in-matrix depolymerization technique was employed.
• Liquid chromatography (LC) coupled with ultraviolet (UV) detection was utilized for sensitive detection and quantification.
• The method was validated using spiked sand samples and subsequently applied to various environmental matrices.

Main Results:

• High recovery rates for PET-spiked sand samples were achieved (99 ± 2% at 1 mg/L and 93 ± 7% at 30 mg/L).
• The limit of quantification (LOQ) for PET was determined for sand (0.4 μg/g), indoor dust (1 mg/g), and wet sludge (0.2 μg/g).
• PET MNPs were detected in indoor dust samples (ranging from 1.2 to 305 mg/g) and sewage sludge (1.5 mg/L), while levels in beach sand were below the limit of detection.

Conclusions:

• The developed 3-step method provides an effective and reliable approach for quantifying PET MNPs in complex environmental samples.
• The method demonstrates good accuracy and sensitivity, making it suitable for environmental monitoring.
• The findings highlight the presence of significant PET MNP contamination in indoor dust and sewage sludge, underscoring the need for further investigation and mitigation strategies.