Study On The Reduction Of Key Toxicants In Mainstream Cigarette Smoke By Bioactive Materials At Filter Level

Health risks induced by smoking are getting worse and worse. International tobacco industries have thus begun to search for the less harmful cigarettes. In the present thesis, systematic study was conducted on the production procedures of cellulose fiber and the corresponding filter tips. Catalase and glutathione have been studied as the representative bioactive materials. Modified cellulose fiber capable of reducing the yields of key toxicants in mainstream cigarette smoke was produced and, detailed investigations have been focused on the related mechanisms. Main research contents and results are as follows:(1) A single-port smoking device was designed and prepared for smoking simulation and sampling followed by smoke analysis.(2) Thin-layer chromatography (TLC) coupled with capillary gas chromatography was adopted for the simultaneously qualitative and quantitative analysis of 16 kinds polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene in mainstream cigarette smoke.(3) High performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was adopted for the simultaneous determination of four kinds of tobacco specific nitrosamines (TSNAs) in mainstream cigarette smoke.(4) Electronic paramagnetic resonance coupled with spin trapping method (EPR-Spin trap) was improved for the determination of free radicals in vapor-phase mainstream cigarette smoke.(5) Systematic research was conducted on the production process of acetate filter rod from cellulose acetate fibers. It was concluded from the results of the researching test that non-soluble additives for the modification of filter tip could be homogeneously sprayed into the matrix of opened cellulose acetate fibers during the procedure of rubberizing.(6) Systematic research was conducted on the production process of cellulose acetate fibers from the raw pulp. It was concluded from the result of the researching test that soluble additives could be homogeneously attached onto the surface of fiber through oiling process.(7) A kind of modified filter tip capable of selectively reducing vapor-phase free radicals was produced with the CTS-CAT as additive. Is was found that the modified filter containing 10 mg CTS-CAT microparticle could apparently lower the level of vapor-phase free radicals by 38.84|%, without affecting the nature of cigarette smoke such as draw resistance, moisture and the nicotine delivery. Judging from the results of the nitrogen oxides assay corresponding to the unconventional smoking simulations, it could be concluded that the selective reduction of vapor-phase free radicals by the modified filter tip could be attributed to the catalase-dependent breakdown of nitric oxide in the presence of peroxides (most probably being H₂O₂), which could have been derived from the dismutation of TPM.(8) A kind of modified cellulose acetate fiber capable of selective reducing key toxicants including vapor-phase free radicals, TSNAs and phenolic compounds was produced with GSH as the additive. Is was found that the GSH content on the surface of the modified fiber was as low as 0.32 mg/g (approximately 0.032 mg for a single filter tip), while showed promising ability to lower the level of vapor-phase free radicals, TSNAs and phenolic compounds by 25.07%, 21.52%(32.14% and 28.04% for NNN and NNK respectively) and 16.54 %, respectively. It was further found by professional sensory evaluation that the GSH containing filter may improve the cigarette smoke flavor due mostly to the reduction of biting-taste compounds such as phenolic compounds..(9) MDA-TBA assay and Ames fluctuation test were adopted to evaluate the impact of modification on the oxidative damage of mainstream cigarette smoke as well as the mutagenic and mutagencity of the corresponding condensate. As a result, the immobilized catalase added in filter apparently reduced the oxidative damage of mainstream smoke and its vapor phase components by 43.57 % and 41.65%, 38.57% and 39.32% GSH, respectively. Beside, the direct and indirect mutagencity potency was reduced by 41.94%, 11.54% by the immobilized catalase, and 32.35%, 55.56 % by GSH, respectively.In conclusion, catalase and glutathione were studied as the representative bioactive materials for the reduction of key toxicants in mainstream cigarette smoke. As a result, smoking-related hazardous was alleviated to some extend. The study in this thesis was not only supposed to have practical significance and application importance for the development of less harmful tobacco products, but also of significance for the further improvement of acetate fiber and cigarette filter tips.