In-house validation of AF4-MALS-UV for polystyrene nanoplastic analysis

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Nanoplastics, particularly polystyrene nanoplastics (PS-NPs), pose environmental and health risks.
• Accurate detection and sizing of PS-NPs are critical for risk assessment and regulatory purposes.
• Traditional analytical methods often struggle with the complexity of nanoplastic mixtures.

Purpose of the Study:

• To evaluate the suitability of asymmetric flow field-flow fractionation (AF4) coupled with multi-angle light scattering (MALS) and UV diode array (UV-DAD) detectors for simultaneous PS-NP detection and sizing.
• To validate the performance of this hyphenated technique according to ISO standards.

Main Methods:

• Asymmetric flow field-flow fractionation (AF4) was used for separation.
• On-line detection was performed using multi-angle light scattering (MALS) and UV diode array (UV-DAD) detectors.
• A mixture of four sizes of polystyrene nanoplastics (20, 60, 100, and 200 nm) was analyzed using 0.2% SDS as a carrier solution.

Main Results:

• The AF4-MALS-UV-DAD method successfully separated PS-NPs of different sizes within 48 minutes.
• Excellent linearity (R²=0.998-0.999), good repeatability (ca. 10%), high recovery (>90%), and sensitive detection limits (15-33 μg/mL) were achieved.
• The method demonstrated good peak resolution and selectivity, with expanded uncertainties for size (16.1-17.9%) and concentration (10.4-14.7%).

Conclusions:

• The hyphenated AF4-MALS-UV-DAD technique is a robust and reliable method for the simultaneous separation, detection, and sizing of polystyrene nanoplastics.
• This method offers significant advantages over traditional single-technique analyses for characterizing complex nanoplastic mixtures.
• The validated method holds great promise for accurate PS-NP analysis in real-world matrices, supporting health and risk assessment studies and regulatory actions.