Consultant to British American Tobacco Investments Ltd, Group Research & Development, Southampton SO15 8TL, UK.
Regul Toxicol Pharmacol. 2011 Feb;59(1):143-8. doi: 10.1016/j.yrtph.2011.01.001.
Cigarette smoke analyte yields are often expressed as ratios relative to tar or nicotine yields, usually to compare different products or to estimate human uptake of smoke in relation to nicotine uptake measurements. The method, however, can lead to distorted interpretations, especially in the case of ratios from ultra-low tar yield cigarettes. In brief, as tar yields decrease below the 5–6 mg per cigarette range, the tar-to-nicotine ratio (TNR) decreases rapidly in a non-linear fashion. If, however, the nicotine yield, rather than the ratio, is plotted versus the tar yield, the non-linearity disappears and a straight line is obtained, with a slight positive intercept for nicotine on the ordinate. Unlike the ratio, the slope appears to depend only on the concentration of the nicotine in the blend and does not appear to vary with smoking parameters such as puff volume, puff interval or length smoked or with cigarette design parameters such as length, circumference or the amount of filtration or filter ventilation. Therefore, such a slope is analogous to the TNR although, unlike that ratio, it is invariant. Even more simply, the concentration of the nicotine in the blend, at least for American blend-style cigarettes, provides a similar index.
香烟烟雾分析物的产率通常表示为相对于焦油或尼古丁产率的比值，通常用于比较不同产品或估计与尼古丁摄取测量相关的人体对烟雾的摄取。然而，这种方法会导致解释失真，特别是在超低焦油产率香烟的情况下。简而言之，当焦油产率下降到每支香烟 5-6 毫克以下时，焦油与尼古丁的比值（TNR）会以非线性方式迅速下降。然而，如果将尼古丁产率而不是比值绘制为焦油产率的函数，则非线性消失，得到一条直线，尼古丁在纵轴上有一个轻微的正截距。与比值不同，斜率似乎仅取决于混合物中尼古丁的浓度，并且似乎不随吸烟参数（如吸气量、吸间隔或吸烟长度）或香烟设计参数（如长度、周长或过滤量或过滤通风）而变化。因此，这样的斜率类似于 TNR，尽管与该比值不同，它是不变的。甚至更简单的是，混合物中尼古丁的浓度（至少对于美国混合风格的香烟）提供了一个类似的指标。
