E-cigarette liquids (e-liquids) contain propylene glycol (PG) and/or glycerol (GL) to deliver flavorants/nicotine. It has recently been suggested that the PG:GL ratio in e-cigarette reservoirs changes during vaping, leaving almost entirely GL after aerosolizing much of a 30:70 PG:GL mixture. To evaluate this directly, we analyzed e-liquids from e-cigarettes before and after aerosolization using 4 different coils, and aerosol samples generated using high and low e-liquid levels. The PG:GL ratios of initial and final e-liquids and aerosol samples were comparable. This is important because a large change in e-liquid composition could substantially alter the aerosol profile during a vaping session.

中文翻译：

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根据 1H NMR 光谱测定，电子烟油箱中丙二醇与甘油的比例不会因蒸发而改变

电子烟液体（e-liquids）含有丙二醇 (PG) 和/或甘油 (GL) 以提供食用香料/尼古丁。最近有人提出，电子烟储液器中 PG:GL 的比例在雾化过程中发生变化，在雾化大部分 30:70 PG:GL 混合物后几乎完全剩下 GL。为了直接评估这一点，我们使用 4 个不同的线圈分析了电子烟气雾化前后的电子烟液，以及使用高和低电子烟液水平生成的气溶胶样品。初始和最终电子液体和气溶胶样品的 PG:GL 比率相当。这很重要，因为电子液体成分的巨大变化可能会在电子烟过程中显着改变气溶胶分布。