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. 2022 May 16;35(5):782-791.
doi: 10.1021/acs.chemrestox.1c00417. Epub 2022 Apr 13.

Influence of Nitrite on Formation of Tobacco-Specific Nitrosamines in Electronic Cigarette Liquids and Aerosols

Xiaohong C Jin  1 , Karl A Wagner  1 , Matt S Melvin  1 , Donna C Smith  1 , Yezdi B Pithawalla  1 , William P Gardner  1 , Karen C Avery  1 , Georgios D Karles  1
Affiliations

Influence of Nitrite on Formation of Tobacco-Specific Nitrosamines in Electronic Cigarette Liquids and Aerosols

Xiaohong C Jin et al. Chem Res Toxicol. .

Abstract

Tobacco-specific nitrosamine (TSNA) formation occurred during aerosol generation from select commercial cig-a-like e-cigarette products. To understand the drivers behind the potential formation of TSNAs in electronic cigarette (e-cigarette) aerosols and e-liquids, model e-liquid systems were generated in the lab to demonstrate that nitrite can react with nicotine and minor alkaloids to form TSNAs in e-liquids. In the presence of nitrite and nicotine, TSNA levels in e-liquids increased over time and the process was accelerated by elevated temperature. Additionally, TSNAs formed during aerosol generation when nitrite was present in the corresponding e-liquids. The commercial e-cigarette products that showed higher levels and formation of TSNAs were observed to contain nitrite and minor alkaloid impurities in the corresponding e-liquids. This study provides valuable information about drivers for TSNA formation in e-liquids and e-cigarette aerosols that may be applied to the evaluation and quality assurance of e-cigarette products.

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Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1
Figure 1
TSNA formation pathway. NO2–- nitrite.
Figure 2
Figure 2
Amount of NNK (A) and NNN (B) in e-liquid 1 fortified with different concentrations of nitrite and evaluated over 12 weeks (n = 3). Over the 12-week study, NNN was not detected in the samples fortified with 2 μg/g nitrite and is not shown on the chart. Error bars not seen in lines are due to small SDs.
Figure 3
Figure 3
TSNA in the aerosols of e-liquid 1 fortified with 0, 2, and 10 μg/g nitrite (n = 3). TSNA not detected or lower than the LOQ are not shown on the chart.
Figure 4
Figure 4
TSNAs in e-liquid 2 with fortified minor alkaloids and nitrite, over 8 weeks (n = 3).
Figure 5
Figure 5
Levels of TSNAs in e-liquid 2 fortified with 0.2 μg/g nitrite and 10 μg/g of each minor alkaloid, respectively, and the corresponding aerosols (n = 3 for e-liquid and n = 4 for aerosol).
Figure 6
Figure 6
TSNA levels in the e-liquid and aerosol of commercial product B (A) and product H (B) (n = 4).
See this image and copyright information in PMC

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