一直以来，电子香烟(e-cigs)被吹捧为一个非常有用的工具，可以帮助吸烟者戒掉传统香烟，大部分人认为传统的香烟被比电子香烟更有害。但是，由于电子香烟也含有尼古丁及可以释放出致癌物，之前提出的观点正确吗？一个研究团队近日在ACS 杂志Chemical Research in Toxicology上发表了一篇文章，报道中称，电子香烟中的大多数尼古丁是可引起成瘾的那种尼古丁。
尽管电子香烟并不燃烧烟草，而是加热使液体蒸发，其中包含尼古丁，调味剂及其他物质。出于考虑到吸入这种混合物，可能会对年轻人的健康产生潜在影响，许多国家已经禁止将电子香烟销售给未成年人。一些专家称，尼古丁可能使电子香烟使用者对其上瘾，或者会引导他们投向传统香烟或其他药物。
但是并不是所有的尼古丁都是一样的，研究尚未调查清楚，在电子香烟液体中的是哪一种尼古丁。在尼古丁的三种形式中，科学家们认为，"自由基"尼古丁是可以被人体吸收的唯一形式，也是最容易上瘾的一种。Najat Saliba和她的同事们想研究清楚，在电子香烟中是哪种尼古丁。
研究人员们测试了售卖的电子香烟中的液体样本，他们发现，大多数的电子香烟中的尼古丁是最容易使人上瘾的那种。他们还发现，电子香烟中尼古丁的含量不定，而且常常与标签上所标明的浓度不吻合。
推荐英文原文报道: E-cigarettes may be as addictive as traditional ones
DOI: 10.1021/acs.chemrestox.5b00107
PMC:
PMID:
Free-base and Protonated Nicotine in Electronic Cigarette Liquids and Aerosols
Najat A. Saliba, et al.
As with other tobacco aerosols, nicotine delivery from e-cigarettes (ECIG) depends on the total nicotine and its partitioning between free-base (Nic) and protonated (NicH+) forms. Previous studies of ECIG nicotine emissions have generally reported "nicotine yield" without attention to whether the methods employed resulted in quantification of the total nicotine or only one of its forms, making reported results difficult to compare across studies or to evaluate against reported blood exposure. This study reports a convenient solvent extraction method for determining total nicotine and its partitioning in ECIG liquids and aerosols by gas chromatography. Commercial ECIG liquids and aerosols were analyzed, and it was found that most of the nicotine was in the Nic form, with aerosols exhibiting higher Nic fraction than the parent liquids. Apparent pH was found to correlate with nicotine partitioning and can provide a useful indirect measure when chromatography is unavailable. Finally, labeled ECIG liquid nicotine concentration in commercial products was often inconsistent with measured nicotine.