Aerosol Mass Spectrometry Analysis of Common Nanoplastic Particles

LIN KONG, Michael A.R. Tawadrous, Alex K.Y. Lee, Man Nin Chan, Arthur W. H. Chan, University of Toronto

     Abstract Number: 80
     Working Group: Chemicals of Emerging Concern in Indoor and Outdoor Aerosol: Sources, Vectors, Reactivity, and Impacts

Abstract
Nanoplastics (NPs) are increasingly recognized as emerging atmospheric contaminants. However, real-time quantification remains challenging due to the current lack of suitable online analytical techniques. While aerosol mass spectrometry (AMS) has demonstrated potential in detecting plastic aerosols, its application to NPs is limited by the absence of polymer-specific relative ionization efficiency (RIE) values and representative calibration standards. To address these limitations, we chemically synthesized atmospherically relevant NPs derived from five common polymer types, polypropylene (PP), low-density polyethylene (LDPE), polystyrene (PS), polyethylene terephthalate (PET), and polyvinyl chloride (PVC), via a top-down emulsified nanoprecipitation approach. This method yielded colloidally stable NPs (30–200 nm) that replicate key physicochemical features of ambient plastics, making them suitable surrogates for analytical development. They retained their polymeric structures, and their chemical integrity was confirmed by pyrolysis gas chromatography-mass spectrometry through identification of characteristic monomeric and oligomeric fragments. High-resolution mass spectra were obtained and the RIE for each polymer was quantified relative to ammonium nitrate. Significant variability in RIE values across different polymers underscores the necessity of polymer-specific calibration for accurate mass quantification. This study presents the first systematic AMS response dataset for atmospherically relevant NPs and establishes a quantitative framework for their identification and source apportionment in ambient aerosols. The use of validated surrogates for real-world NPs enhances the reliability and atmospheric relevance of AMS-based detection, supporting real-time quantification and improved integration into atmospheric transport and exposure models for plastic-derived aerosols.