Integrating AF4 and Py-GC-MS for Combined Size-Resolved Polymer-Compositional Analysis of Nanoplastics with...

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Nanoplastics are pervasive environmental pollutants.
• Standardized methods for nanoplastic characterization and quantification in environmental samples are lacking.
• Accurate analysis is crucial for understanding nanoplastic risks.

Purpose of the Study:

• To develop and validate a novel workflow for nanoplastic analysis in environmental water samples.
• To enable comprehensive characterization of nanoplastic size distribution and polymer composition.
• To assess the applicability of the workflow in complex matrices like wastewater.

Main Methods:

• An offline combination of asymmetrical flow field-flow fractionation with multiangle light scattering (AF4-MALS) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS).
• AF4-MALS for sample cleanup and size separation down to approximately 1 nm.
• Py-GC-MS for identification and quantification of polymers within separated size fractions.

Main Results:

• The AF4-MALS-Py-GC-MS workflow successfully identified nanoplastics in wastewater samples.
• Quantification limits varied by polymer type, from 0.64 ng (polystyrene) to 180 ng (polyolefins).
• 8.8 ± 1.8 ng/mL of polystyrene nanoplastics were quantified; polyvinyl chloride was potentially identified in untreated wastewater.

Conclusions:

• The developed workflow provides a promising foundation for particulate polymer analysis in environmental matrices.
• The combination of techniques offers comprehensive information on nanoplastic size and composition.
• Further refinement is needed to address challenges such as low recovery and potential matrix interferences.