Plastic production started early in the 20<sup>th</sup> century and has dramatically changed the materials we use every day. Unfortunately, enormous quantities of plastic waste have been generated each year and are expected to grow to a total value of 26 billion tons by the year 2050. Breakdown products of plastic waste, micro-, and nanoplastic are of particular concern because of the ease of their distribution in the environment (e.g., air, water, soil). They are ubiquitous, and chronic exposure via inhalation or ingestion can be detrimental to human health. This is compounded by the fact that persistent pollutants can adsorb on these materials and cause further harm.  The goal of this study was to identify micro- and nanoplastics in the environment, as well as characterize adsorbed persistent organic pollutants associated with these dangerous materials. Unfortunately, the characterization of these pollutants is challenging due to their chemical diversity and trace concentrations in complex plastic samples. Sample analyses were carried out in two steps: 1) Thermal desorption followed by 2) pyrolysis with chromatographic separation and detection using comprehensive two-dimensional gas chromatography, a novel ionization source, and high-resolution time-of-flight mass spectrometry. Instrument software afforded complete control over the autosampler, chromatograph, and mass spectrometer, in addition to automated instrument optimization for a seamless transition between the three ionization modes.<br/>The analysis methodology resulted in comprehensive data with exceptional peak alignment between ionization modes, better S/N, and an increase in the total number of compounds identified. Electron Ionization (EI) data were utilized to identify compounds through untargeted processing which consisted of spectral similarity searches of large databases, and formula determinations from molecular, and fragment ions. Positive Chemical Ionization (PCI) and Electron Capture Negative Ionization (ECNI) spectra provided complementary molecular formula information to increase confidence in compound annotation. Advanced software tools (e.g., scaled mass defect plots) allowed for both untargeted data processing as well as retrospective targeted analysis of the comprehensive data. The analyses resulted in the identification of polymers and annotation of adsorbed materials such as heterocyclic compounds, aromatics, polyaromatics, and bisphenols.

Comprehensive analysis of micro- and nanoplastics using high-resolution mass spectrometry with enhanced chromatographic resolution

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