AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Applying Mass Spectral Techniques to Identify the Chemical Composition of e-Cigarette Smoke and Its Surrogates: Implications for Source Apportionment
YUE ZHANG, Sarah Suda Petters, Manjula Canagaratna, Jonathan Thornburg, Jason Surratt, University of North Carolina at Chapel Hill
Abstract Number: 730 Working Group: Aerosol Exposure
Abstract Electronic cigarettes (e-cigarettes), a new type of cigarette that vaporizes a mix of chemicals (so called e-liquids, which includes nicotine, is getting increasingly popular among the general population (especially in adolescents) due to its claim of being safer than traditional cigarettes. As a result, it is important to identify the chemical constituents that make up this aerosol mixture to aid in exposure assessments. This study systematically examines the chemical properties of e-liquids from an aerosol atomizer and a commercially available e-cigarette device with a range of selected compositions and operation settings. Results show that despite e-liquids consisting of primarily propylene glycol (PG) and glycerol (VG), most of the aerosol composition is dominated by VG due to its lower vapor pressure. Positive matrix factorization (PMF) of aerosol mass spectral data was successfully applied to the e-cigarette smoke with varying compositions in order to separate the mass contributions of pure PG and VG to the generated aerosols. Tracers ions with mass-to charge ratios (m/z) at 27, 41, 55, and 70 were characteristic of aerosols containing pure PG, while ions at m/z 15, 31, 43, and 61 were associated with pure VG-derived aerosols. The aerosol mass spectra of pure PG and VG were also combined with the multilinear engine (ME-2) in order to conduct source apportionment of PG and VG in both the atomized aerosols and e-cigarette smoke. Results were compared with aerosols collected on filters that were analyzed by liquid chromatography interfaced to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (RPLC/ESI-HR-QTOFMS). VG was found to be the main component of aerosols vaporized from most e-liquids. This study establishes a source appointment method that can used to identify e-cigarette smoke and the relative contributions of pure PG- and VG-derived aerosols, and thus, can be used for air monitoring, tobacco control, and health improvement.