Formation of Redox-Active Duroquinone from Vaping of Vitamin E Acetate Contributes to Oxidative Lung Injury

Canchola, Alexa; Ahmed, C. M. Sabbir; Chen, Kunpeng; Lin, Ying-Hsuan

doi:10.1021/acs.chemrestox.1c00309

Cited by 17 publications

(28 citation statements)

References 63 publications

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“…THC has a stronger tendency to degrade compared to VEA. − Regarding ketene that has been suggested to be formed by vaping or pyrolytic heating of VEA, it is not clear whether it is identifiable with our methods or is not formed at the temperatures tested here. Products like duroquinone and durohydroquinone ,− are reported to be formed below a vaping coil temperature of 300 °C; however, we do not observe them with the preparation or detection methods used in this work. The selectivity and solubility of GC-MS extraction solvent could be a reason why products like quinones were not observed in the current study.…”

Section: Discussioncontrasting

confidence: 65%

Vaping Aerosols from Vitamin E Acetate and Tetrahydrocannabinol Oil: Chemistry and Composition

Dai

Tran

et al. 2022

Chem. Res. Toxicol.

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The popularity of vaping cannabis products has increased sharply in recent years. In 2019, a sudden onset of electronic cigarette/vaping-associated lung injury (EVALI) was reported, leading to thousands of cases of lung illness and dozens of deaths due to the vaping of tetrahydrocannabinol (THC)-containing e-liquids that were obtained on the black market. A potential cause of EVALI has been hypothesized due to the illicit use of vitamin E acetate (VEA) in cannabis vape cartridges. However, the chemistry that modifies VEA and THC oil, to potentially produce toxic byproducts, is not well understood under different scenarios of use. In this work, we quantified carbonyls, organic acids, cannabinoids, and terpenes in the vaping aerosol of pure VEA, purified THC oil, and an equal volume mixture of VEA and THC oil at various coil temperatures (100−300 °C). It was found under the conditions of our study that degradation of VEA and cannabinoids, including Δ 9 -THC and cannabigerol (CBG), occurred via radical oxidation and direct thermal decomposition pathways. Evidence of terpene degradation was also observed. The bond cleavage of aliphatic side chains in both VEA and cannabinoids formed a variety of smaller carbonyls. Oxidation at the ring positions of cannabinoids formed various functionalized products. We show that THC oil has a stronger tendency to aerosolize and degrade compared to VEA at a given temperature. The addition of VEA to the e-liquid nonlinearly suppressed the formation of vape aerosol compared to THC oil. At the same time, toxic carbonyls including formaldehyde, 4-methylpentanal, glyoxal, or diacetyl and its isomers were highly enhanced in VEA e-liquid when normalized to particle mass.

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Section: Discussioncontrasting

confidence: 65%

Vaping Aerosols from Vitamin E Acetate and Tetrahydrocannabinol Oil: Chemistry and Composition

Dai

Tran

et al. 2022

Chem. Res. Toxicol.

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“…However, our results clearly demonstrate degradation of VEA and formation of products such as DQ at 176˚C, indicating that the device itself may play a larger role in the decomposition of VEA than initially anticipated. Previous study in our lab has also found substantial formation of DQ at 218˚C-several hundred degrees lower than what has been predicted [24]. To further understand if the device itself may impact the thermal degradation of VEA, pure pyrolysis of VEA oil was carried out using a tube furnace reactor.…”

Section: Potential Catalysis Of Vea Vaping Pyrolysismentioning

confidence: 92%

“…The vaping emissions were collected using a cold trap apparatus maintained at -40˚C (Across International LLC). The particle collection efficiency of the cold trap system at the flow rate used in this study has been reported previously (� 99% by volume) [24]. To collect aerosol emissions, one 4 s puff was taken at intervals of 1 min to maintain consistency with the temperature measurement procedure.…”

Section: E-cigarette Collectionmentioning

confidence: 99%

“…Finally, the vaping topography used in this study was adapted from previous literature on nicotine vaping and optimized for capture of particles in the cold trap system [24]. Real-word nicotine vape users have been reported to inhale between 50-80 mL/puff at greater flow rates than used in this study [47,48], whereas parameters for THC-vaping have not been well-characterized at this time [49].…”

Section: Limitationsmentioning

confidence: 99%

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Temperature dependence of emission product distribution from vaping of vitamin E acetate

et al. 2022

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Nearly two years after vitamin E acetate (VEA) was identified as the potential cause of the 2019–2020 outbreak of e-cigarette, or vaping product-associated lung injuries (EVALI), the toxicity mechanisms of VEA vaping are still yet to be fully understood. Studies since the outbreak have found that e-liquids such as VEA undergo thermal degradation during the vaping process to produce various degradation products, which may pose a greater risk of toxicity than exposure to unvaped VEA. Additionally, a wide range of customizable parameters–including the model of e-cigarette used, puffing topography, or the applied power/temperature used to generate aerosols–have been found to influence the physical properties and chemical compositions of vaping emissions. However, the impact of heating coil temperature on the chemical composition of VEA vaping emissions has not been fully assessed. In this study, we investigated the emission product distribution of VEA vaping emissions produced at temperatures ranging from 176 to 356°C, corresponding to a variable voltage vape pen set at 3.3 to 4.8V. VEA degradation was found to be greatly enhanced with increasing temperature, resulting in a shift towards the production of lower molecular weight compounds, such as the redox active duroquinone (DQ) and short-chain alkenes. Low temperature vaping of VEA resulted in the production of long-chain molecules, such as phytol, exposure to which has been suggested to induce lung damage in previous studies. Furthermore, differential product distribution was observed in VEA degradation products generated from vaping and from pyrolysis using a tube furnace in the absence of the heating coil at equivalent temperatures, suggesting the presence of external factors such as metals or oxidation that may enhance VEA degradation during vaping. Overall, our findings indicate that vaping behavior may significantly impact the risk of exposure to toxic vaping products and potential for vaping-related health concerns.

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“…Therefore, ketene does not survive long enough to be detected intact in vivo . Chemical and physical studies such as reported herein and by others ,− are thus needed to elucidate sources of exposure.…”

mentioning

confidence: 99%

Vaping Cannabinoid Acetates Leads to Ketene Formation

Munger

Jensen²,

Strongin

2022

Chem. Res. Toxicol.

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Δ 8 -THC acetate is a relatively new psychoactive cannabis product that is available online and in vape shops across the United States since it is currently largely unregulated. Because it contains a similar substructure to vitamin E acetate, which has been shown to form the poison gas ketene during vaping, we investigated potential ketene formation from Δ 8 -THC acetate, as well as two other cannabinoids acetates, CBN acetate and CBD acetate, under vaping conditions. Ketene was consistently observed in vaped condensates from all three cannabinoid acetates as well as from a commercial Δ 8 -THC acetate product purchased online.

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Formation of Redox-Active Duroquinone from Vaping of Vitamin E Acetate Contributes to Oxidative Lung Injury

Cited by 17 publications

References 63 publications

Vaping Aerosols from Vitamin E Acetate and Tetrahydrocannabinol Oil: Chemistry and Composition

Vaping Aerosols from Vitamin E Acetate and Tetrahydrocannabinol Oil: Chemistry and Composition

Temperature dependence of emission product distribution from vaping of vitamin E acetate

Vaping Cannabinoid Acetates Leads to Ketene Formation

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