Thermal Degradants Identified from the Vaping of Vitamin E Acetate

Abstract

Studies have suggested that vitamin E acetate (VEA), when used in an electronic vaping device, undergoes thermal degradation and is considered one of the main contributors in e-cigarette or vaping product use-associated lung injury (EVALI). Using a Borgwaldt 5.1 linear smoker, a SVS250 Electronic Vaporizer and two types of tank systems, VEA was analyzed for degradation products produced via the Cooperation Centre for Scientific Research Relative to Tobacco method 81 when the filter containing vaporized VEA was extracted using acetonitrile. Two of the major products identified were 2,3,5,6-tetramethyl-1,4-benzoquinone and 2,6,10,14-tetramethyl-1-pentadecene, which were confirmed using analytical standards and gas chromatography-high-resolution mass spectrometry (GC-HRMS). Additional synthesis of 4-acetoxy-2,3,5,6-tetramethyl-2,4-cyclohexadienone and subsequent characterization using nuclear magnetic resonance and GC-HRMS suggested that this is not one of the products produced. Identification of these degradants will allow future studies to quantify and examine the degradants in vivo and in vitro as biomarkers for exposure and toxicity assessment.

Figure 1.

GC–HRMS chromatograms of full scan data from 10 to 30 min of (a) VEA standard, (b) DQ standard, (c) TMPD standard, (d) extract from VEA vaporized in a Baby M2 tank and (e) extract from VEA vaporized in a Exxus tank.

Figure 2.

Extracted spectra of the peak found at 28.45 min. (Top) Spectra extracted from VEA vaporized in Baby M2 and extracted in acetonitrile. (Bottom) Spectra extracted from VEA standard in acetonitrile. (Inset) molecule and theoretical exact mass of VEA. Additional m/z values can be found in Supplementary Table S2.

Figure 3.

Extracted spectra of the peak found at 16.53 min. (Top) Spectra extracted from VEA vaporized in Baby M2 and extracted in acetonitrile. (Bottom) Spectra extracted from TMPD standard in acetonitrile. (Inset) molecule and theoretical exact mass of TMPD. Additional m/z values can be found in Supplementary Table S2.

Figure 4.

Extracted spectra of the peak found at 11.65 min. (Top) Spectra extracted from VEA vaporized in Baby M2 and extracted in acetonitrile. (Bottom) Spectra extracted from duroquinone standard in acetonitrile. (Inset) molecule and theoretical exact mass of duroquinone. Additional m/z values can be found in Supplementary Table S2.