A Study On Puff-by-puff Delivery Discipline Of The Important Harmful Components And Aroma Components In Mainstream Cigarette Smoke

As people become increasingly concerned about health issues, "smoking is harmful to health" attracts people’s attention, and the smokers pay more attention to comfort at the same time in the pursuit of physiological satisfaction. Tobacco industry begins to take efforts to reduce the tar content of burning cigarettes and expand researches on the important topic of increasing flavor and reducing harm. With the in-depth studies on the harmful ingredients and flavor components, more and more researches are conducted domestically and abroad on puff-by-puff smoking, because such studies can make clear the puff-by-puff release rules of various chemical ingredients during smoking and provide theoretical reference for increasing flavor and reducing harm of low-tar cigarettes.In this thesis, we study the effects of the tipping paper on the puff-by-puff release rules of some harmful ingredients of mainstream smoking gas(routine chemical components, crotonaldehyde and hydrocyanic acid), and develop headspace(HS)-solid phase microextraction(SPME)-gas chromatography(GC)/mass spectrometry(MS) methods for analyzing the puff-by-puff release amounts of eight major mainstream smoking aroma components(furfural, 5-methyl furfural, D-limonene, β-damascenone, pyridine, 3-methyl pyridine, pyrrole, 2,3,5,6-four methyl pyrazine). The release rules of the above chemical ingredients of mainstream smoke are obtained, which can provide theoretical support for developing new, low-tar and high-flavor cigarettes. The main contents are as follows.1. Effects of the tipping paper on the puff-by-puff release amounts of some harmful ingredients were studied. The release amounts of some routine chemical components of mainstream cigarette smoke, i.e. total particulate matter(TPM), nicotine, H2 O, tar and CO, were determined by GC. The permeabilities of the tipping paper were 0 CU, 50 CU, 250 CU, 500 CU and 700 CU. It is found that withthe increase of permeability, the puff-by-puff release and the total emissions of harmful ingredients are reduced. The release amount for the same tipping paper increased puff by puff, and the increasing amplitude follows the order TPM> tar> H2O> nicotine. The increasing trend became more obvious with the increase of permeability. The puff-by-puff release of HCN in solid and gas phases of mainstream smokes of 5 cigarettes was examined based on a continuous gas flow method. With the increase of air permeability of the tipping paper, the puff-by-puff release of HCN was reduced. The HCN release in the solid phase was relatively uniform but that in the gas phase was largely increased with the increase of the puff number. The puff–by-puff release of crotonaldehyde of mainstream cigarette smoke was examined by high performance liquid chromatography(HPLC). The release of crotonaldehyde was reduced by increasing the permeability of cigarette tipping paper, and the puff-by-puff release showed a slight increasing trend with relatively small total change. These results indicate that the puff-by-puff release rules of chemical components in mainstream cigarette smoke are different when different chemical components or different-permeability tipping papers are used.2. A HS-SPME-GC/MS method was established to study the release discipline of 8 kinds of important aroma constituents(pyridine, pyrrole, furfural, 5-methyl furfural,3-methylpyridine, D-limonene, 2,3,5,6-tetramethyl pyrazine and β-damascenone) in the mainstream smoke. The optimized conditions are 85 μm CAR/PDMS solid-phase exaction fibre, exaction temperature at 60 oC, extraction time of 60 min, desorption temperature at 250 oC and desorption time of 8 min. Under optimum conditions, the linear correlation coefficient of the working curve, the relative standard deviation and the recovery of standard addition for these 8 aromatic constituents were between 0.9698~0.9995, 3.8%~9.0% and 78%~105%, respectively. With the increase of puff number, the puff-by-puff release of the main aromatic constituents in the mainstream smoke was generally even, but the second puff, the third puff and the sixth puff release of aromatic constituents were relatively high,and the release discipline differs for the aromatic constituents.3. By using the above-established HS-SPME-GC/MS method, the effects of cigarette paper permeability on release discipline of the aroma components in puff-by-puff mainstream cigarette smoke were investigated. Three permeabilities of cigarettes(40 CU, 50 CU and 60 CU) and 8 main aroma components were involved. With the increase of cigarette paper permeability, the release amounts of TPM and CO were reduced, but the release amount of tar was less affected. Tar, nicotine, H2 O or CO release in mainsream smoke was gradually rising puff by puff. The different cigarette paper permeability gave different release-quantity-change rules for various suction numbers. The release of 5-methyl furfural, furfural, and D-limonene were relatively high among the 8 aroma components. The release amounts of the 8 aroma components in mainstream smoke were all very low in the first puff, but they increased largely in the second puff and afterwards became slowly increasing, but the release amount of furfural, pyridine, and 3-methyl pyridine still changed relatively largely.