Abstract
Research gaps exist in toxic metals characterization in e-cigarette, or vaping, products (EVPs) as these analytes typically have low concentrations and most standard aerosol trapping techniques have high metals background. An additional complication arises from differences in the EVP liquid formulations with nicotine products having polar properties and non-nicotine products often being non-polar. Differences in polar and non-polar matrices and the subsequent aerosol chemistries from various EVPs required modifications of our previously reported nicotine-based EVP aerosol method. Validation and application of the expanded method, suitable for both hydrophobic and hydrophilic aerosols, are reported here. The metals analyzed for this study were Al, Cr, Fe, Co, Ni, Cu, Cd, Sn, Ba, and Pb. The method limits of detection for the modified method ranged from 0.120 ng/10 puffs for Cd to 29.3 ng/10 puffs for Al and were higher than reported for the previous method. Results of the analyses for metals in aerosols obtained from 50 EVP products are reported. Cannabinoid based EVP aerosols were below reportable levels, except for one sample with 16.08 ng/10 puffs for Cu. Nicotine-based EVP results ranged from 6.72 ng/10 puffs for Pb to 203 ng/10 puffs for Sn. Results of the analyses for these metals showed that aerosols from only 5 of the 50 devices tested had detectable metal concentrations. Concentrations of toxic elements in the aerosols for nicotine-based EVP aerosol metal concentration ranges were consistent with previously published results of aerosol analyses from this class of devices.