Detecting Polystyrene Nanoparticles in Environmental Samples: A Comprehensive Quantitative Approach Based on...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Submicrometer-sized plastic particles, termed nanoplastics (NP), are prevalent in diverse ecosystems.
• NP exist within complex organic matrices, posing analytical challenges for accurate quantification.
• Existing methods struggle to differentiate NP signals from interfering compounds.

Purpose of the Study:

• To develop a robust analytical workflow for accurate nanoplastic quantification.
• To overcome challenges posed by complex organic matrices in environmental samples.
• To establish a method for identifying and quantifying specific nanoplastic types, like polystyrene.

Main Methods:

• Utilized Thermal Desorption-Proton-Transfer Reaction-Mass Spectrometry (TD-PTR-MS) for chemical selectivity.
• Developed a novel workflow combining Non-Negative Matrix Factorization (NMF) and Multivariate Standard Addition (MSA).
• Applied the workflow to separate and quantify nanoplastic signatures from complex mixtures.

Main Results:

• The NMF-MSA workflow successfully separated nanoplastic signals from organic interferents.
• Achieved matrix-corrected nanoplastic fingerprints for identification and quantification.
• Quantified polystyrene nanoplastics in environmental samples in the low nanogram range (e.g., 4.7 ng/mL in river water, up to 129 ng/g in sand).

Conclusions:

• The novel NMF-MSA workflow provides a reliable method for nanoplastic quantification.
• Demonstrated the method's efficacy in real-world environmental samples.
• The findings enable more accurate environmental monitoring of nanoplastic pollution.