Exposure to (micro/nano)-plastics and their combustion products studied by cyclic ion mobility-mass spectrometry

Abstract

Degradation of plastics in the environment has led to formation of micro/nano-plastics (MNPs). Currently, there are only a few studies measuring plastic particles smaller than 1 µm in air. As such, the goal of this study was to develop a method for identification and quantification of MNPs in indoor air. Particulate matter (PM) from two indoor environments was size-resolved using a Micro-Orifice Uniform Deposit Impactor (MOUDI) model 110 cascade impactor ranging from 56 nm to 18 µm in size. The GCxcIM-MS method was then developed to characterize four common plastics: polystyrene (PS), polyethylene (PE), polypropylene (PP), and polymethyl methacrylate (PMMA). The results indicated that approximately 57-67% of MNPs had particle diameters >2.5 µm, and these microplastics constituted 50-60% of the total particulate matter in private residences. Moreover, the comprehensive two-dimensional separation provided by the developed method enabled us to analyze other polymers and plastic additives. For instance, plastic additives such as TDCPP (Tris (1, 3-dichloro-2-propyl) phosphate) was detected, and its concentration correlated with polyurethane (PU). Plastic can also pose a risk to human health when they are combusted. The goal of second chapter was differentiation between toxic and non-toxic halogenated of polycyclic aromatic hydrocarbons (HPAHs) isomers that were released during combustion of plastics. The geometry of cIM-MS allows ions to travel multiple passes through cyclic cell such that, the greater of pass numbers, the better resolution of isomers. When a complex real sample was studied in this way, the toxic 2367-tetrachloroanthracene (2367-TCA) was separated from a mix of 17 other isomers with the assistance of an advanced “unwrapping” data analysis technique.