Ultrastable long-term tracking and quantification of nanoplastics in complex environmental matrices

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Micro- and nano-plastics (MNPs) are significant environmental pollutants, particularly in aquatic ecosystems.
• Accurate long-term tracking and quantification of MNPs in complex environmental matrices remain a challenge.

Purpose of the Study:

• To develop a stable and reliable method for the quantitative tracking of nanoplastics in environmental samples.
• To synthesize core-shell nanoplastics (EU@PS) utilizing Europium (Eu) chelates as a dual-functional tracer.

Main Methods:

• Synthesis of core-shell nanoplastics (EU@PS) with Eu chelates.
• Quantitative tracking using single-particle ICP-MS and fluorescence imaging.
• Microcosm experiments to assess partitioning, sedimentation, and bioaccumulation in *D. magna*.

Main Results:

• EU@PS demonstrated high sensitivity (detection limit ~0.5 μg/L) and exceptional tracer stability (>83.1% mass retention after 28 days, UV unaffected).
• Over 95% of particles settled in sediment within 10 days, with a sedimentation rate constant of 0.20/day.
• Fluorescence imaging revealed particle accumulation in *D. magna* guts, reaching 4.8 μg/g at 50 μg/L exposure.

Conclusions:

• The developed EU@PS tracer offers a stable and sensitive method for long-term environmental fate studies of nanoplastics.
• Tracer stability is critical for accurate quantification and understanding MNP behavior in aquatic ecosystems.
• This method aids in assessing MNP partitioning, sedimentation, and bioaccumulation dynamics.