Targeted and non-targeted analysis of microplastics exposure using pyrolysis gas chromatography ion mobility mass spectrometry

Plastics are synthetic materials composed of organic polymers and additives such as plasticizers, flame retardants, and antioxidants, some of which can adversely affect human health. Over time, larger plastics and fibers fragment through weathering, mechanical degradation, and sunlight into smaller particles known as microplastics (<5 mm) and nanoplastics (<0.1–1 μm), collectively termed MNPs. Their widespread presence raises concern about potential health risks, yet detecting trace levels remains challenging. This thesis presents two projects that provide new insight into microplastics exposure. The first project developed a sensitive method for quantifying trace levels of polystyrene (PS), polyethylene (PE), and polyvinyl chloride (PVC) in drinking water using filtration, accelerated solvent extraction, and pyrolysis gas chromatography–ion mobility spectrometry (pyr-GC-IMS). Detection limits were 0.52 ng/L for PS, 7.1 ng/L for PE, and 13.0 ng/L for PVC, with recoveries above 60%. Application to household water samples in St. John’s (n = 6) revealed 18 ng/L of PE and 31 ng/L of PVC, corresponding to a daily intake of ~392 ng—well below estimated inhalation exposure levels. The second project applied a non-targeted GC-cIMS method to characterize halogenated compounds associated with airborne MNPs. Several fluorinated species were tentatively identified, suggesting a potential link between indoor PFAS and textile sources contributing to human exposure.