Abstract：
The widespread use of flavored e-cigarettes has led to a significant rise in teenage nicotine use. In e-liquids, the flavor carbonyls can form acetals with unknown chemical and toxicological properties. These acetals can cause adverse health effects on both smokers and nonsmokers through thirdhand exposure. This study aims to explore the impacts of these acetals formed in e-cigarettes on indoor partitioning and thirdhand exposure. Specifically, the acetalization reactions of commonly used flavor carbonyls in laboratory-made e-liquids were monitored using proton nuclear magnetic resonance (1H NMR) spectroscopy. EAS-E Suite and polyparameter linear free energy relationships (PP-LFERs) were employed to estimate the partitioning coefficients for species. Further, a chemical two-dimensional partitioning model was applied to visualize the indoor equilibrium partitioning and estimate the distribution of flavor carbonyls and their acetals in the gas phase, aerosol phase, and surface reservoirs. Our results demonstrate that a substantial fraction of carbonyls were converted into acetals in e-liquids and their chemical partitioning was significantly influenced. This study shows that acetalization is a determinant factor in the exposure and toxicology of harmful carbonyl flavorings, with its impact extending to both direct exposure to smokers and involuntary exposure to nonsmokers.
摘要：
加味电子烟的广泛使用导致青少年尼古丁使用显着增加。在电子液体中，风味羰基可以形成具有未知化学和毒理学性质的缩醛。这些缩醛通过三手暴露会对吸烟者和非吸烟者造成不利的健康影响。本研究旨在探讨电子烟中形成的这些缩醛对室内分区和三手暴露的影响。具体来说,使用质子核磁共振（1HNMR）光谱法监测实验室制造的电子液体中常用的风味羰基化合物的缩醛化反应。EAS-ESuite和多参数线性自由能关系（PP-LFER）用于估计物种的分配系数。Further,应用化学二维分配模型来可视化室内平衡分配，并估计气相中风味羰基及其缩醛的分布。气溶胶相,和地面水库。我们的结果表明，大部分羰基化合物在电子液体中转化为缩醛，并且它们的化学分配受到显着影响。这项研究表明，缩醛化是有害羰基调味剂暴露和毒理学的决定因素，其影响扩展到直接暴露于吸烟者和非自愿暴露于非吸烟者。
