不同单料烟叶主流烟气气溶胶粒度分布差异

Differences of aerosol particle size distribution in cigarette mainstream smoke of unblended leaf tobacco

为考察不同产地单料烟叶主流烟气气溶胶粒度分布差异以及16种多环芳烃的粒径分布规律，制备了20种不同产地单料烟叶的卷烟和3种不同膨胀梗丝掺配比例的卷烟，利用单孔道吸烟机和测量范围在0.007～9.970μm的电子低压撞击器对样品主流烟气气溶胶粒子质量和数量进行了测量。结果表明：1不仅不同国家单料烟叶主流烟气气溶胶粒度分布有差异，而且国内不同产地单料烟叶主流烟气气溶胶粒度分布也存在显著差异；国内烟叶的粒子质量和数量总体比国外的偏大；烟叶的化学成分和物理结构等因素导致其燃烧特性不一致可能产生了气溶胶粒度分布差异；2同一产地不同品种烟叶主流烟气气溶胶粒度分布是有差异的。在选取的三个品种中红大品种的粒子质量和数量均最大，云85/87品种的粒子质量和数量均最小；3不同部位烟叶主流烟气气溶胶粒度分布是有差异的，不同产地烟叶部位的气溶胶粒度分布规律并不完全一致；4烟丝中掺配膨胀梗丝的比例对主流烟气气溶胶粒度分布产生一定的影响。当膨胀梗丝的比例增加时，气溶胶粒子的质量降低；粒子数量呈先增加后降低的趋势；5不同产地的单料烟叶主流烟气中PAHs质量的粒径分布规律相似，粒径分布呈现单峰分布，在0.4829μm粒径段含量最高；分子量较低的3～4环化合物占PAHs总量比例超过80%。

20 cigarette samples of different leaf tobacco and 3 cigarette samples of expanded cut stems with different blending ratios were used to investigate differences of aerosol particle size distribution in cigarette malnstream smoke and distribution of polycyclic aromatic hydrocarbons（PAHs）,. The diameter, number and mass of the particles in aerosol were directly determined by using smoking machine LM1 and electrical low pressure impactor （ELPI） with a measurement range from 7 - 9970 nm. Results showed that： 1） Differences of aerosol particle size distribution not only existed in leaf tobacco from different countries, but also existed in leaf tobacco from different regions of China. The mass and number of aerosol particles of domestic leaf tobacco were larger than those from abroad. Chemical composition and physical structure of tobacco leaves lead to different combustion characteristics, which might incur differences in aerosol particle size distribution. 2） Differences of aerosol particle size distribution existed in different tobacco varieties in the same region. The mass and number of particles of Honghuadajinyuan were the largest among all tested tobacco varieties, while those of Yunyan85/87 were the smallest. 3） Differences of aerosol particle size distribution existed in tobacco leaves from various stalk positions, and particle size distribution was not consistent in tobacco leaves from different regions. 4） Expanded cut stems with different blending ratios would affect particle size distribution. The mass of particles in aerosol decreased with the increase of the proportion of expanded cut stems, while the number of the particles decreased at first and then increased. 5） Particle size distribution of PAHs was similar among different tobacco growing regions, and displayed unimodal distribution. The highest content was in 0.4829μm, and 3 ~ 4 ring compounds accounted for more than 80% of total PAHs.