Chem Res Toxicol. 2019 Jun 17;32(6):974-976. doi: 10.1021/acs.chemrestox.9b00076. Epub 2019 May 22.
Heat-not-burn products, eg, I quit ordinary smoking (IQOS), are becoming popular alternative tobacco products. The nicotine aerosol protonation state has addiction implications due to differences in absorption kinetics and harshness. Nicotine free-base fraction (α) ranges from 0 to 1. Herein, we report α for IQOS aerosols by exchange-averaged H NMR chemical shifts of the nicotine methyl protons in bulk aerosol and verified by headspace-solid phase microextraction-gas chromatography-mass spectrometry. The α ≈ 0 for products tested; likely a result of proton transfer from acetic acid and/or other additives in the largely aqueous aerosol. Others reported higher α for these products, however, their methods were subject to error due to solvent perturbation.
加热不燃烧产品，例如 IQOS，正成为流行的替代烟草产品。由于吸收动力学和刺激性的差异，尼古丁气溶胶质子化状态与成瘾有关。尼古丁游离碱分数（α）的范围为 0 到 1。在此，我们通过交换平均化尼古丁甲基质子的 H NMR 化学位移报告了 IQOS 气溶胶中的 α，这在大气溶胶中得到了验证，并通过顶空固相微萃取-气相色谱-质谱法进行了验证。测试的产品的 α≈0；这可能是由于大气溶胶中大部分为水相中存在的乙酸和/或其他添加剂的质子转移所致。其他人报道了这些产品的更高的 α，但由于溶剂干扰，他们的方法存在误差。
