High-performance micro/nanoplastics characterization by MALDI-FTICR mass spectrometry

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Micro/nanoplastics (MNPs) are pervasive environmental pollutants with significant health implications.
• The heterogeneity of MNP sizes and compositions presents a major challenge for accurate characterization.
• Reliable analytical methods are crucial for understanding MNP risks and developing mitigation strategies.

Purpose of the Study:

• To develop and optimize a robust mass spectrometry-based strategy for the unambiguous identification and characterization of various MNPs.
• To enhance the sensitivity and reliability of MNP analysis using optimized sample preparation and detection parameters.
• To validate the applicability of the developed method for analyzing MNPs from diverse environmental sources.

Main Methods:

• Establishment of a matrix-assisted laser desorption ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) approach.
• Systematic optimization of MNP sample preparation and detection conditions using response surface methodology.
• Utilizing the ultrahigh mass resolution of FTICR MS for precise structural elucidation of MNPs.

Main Results:

• The MALDI-FTICR MS strategy successfully characterized multiple MNP types, including polystyrene, polyethylene glycol terephthalate, polyamide, polymethyl methacrylate, acrylonitrile butadiene styrene copolymer, and polycarbonate.
• Optimization of experimental conditions led to an average 1.5-fold improvement in MS detection signal-to-noise ratios.
• The method demonstrated high efficiency in characterizing polymer compositions of environmental MNPs from sources like foam, bottles, cable ties, and compact discs.

Conclusions:

• The developed MALDI-FTICR MS strategy provides unambiguous characterization of diverse micro/nanoplastics.
• This technique offers a highly efficient and promising tool for environmental MNP detection and safety evaluation.
• The ultrahigh mass resolution of FTICR MS is critical for accurate MNP structural analysis.