This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan.Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in differ...This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan.Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages.The mainstream smoke particulate matter was collected by a Cambridge filter pad,digested by a microwave digestor,and then analyzed for contents of heavy metal ions,including As(III/V),Pb(II),Cd(II),Cr(III/VI) and Ni(II),by graphite furnace atomic absorption spectrometry(GFAAS).The results showed that chitosan had a removal effect on Pb(II),Cd(II),Cr(III/VI) and Ni(II).Of these,the percent removal of Ni(II) was elevated with an increasing dosage of chitosan.Chitosan of a high deace tylation degree exhibited good binding performance toward Cd(II),Cr(III/VI) and Ni(II),though with poor efficiency for Pb(II).Except As(III/V),all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight.Nonetheless,the percent removal of Cr(III/VI) peaked with a chitosan molecular weight of 200 kDa,followed by a dramatic decrease with an increasing chitosan molecular weight.Generally,chitosan had different removal effects on four out of five tested metal ions,and the percent removal of Cd(II),Pb(II),Cr(III/VI) and Ni(II) was approximately 55%,45%,50%,and 16%,respectively.In a word,chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke,improve cigarette safety,and reduce the harm to smokers.展开更多
To understand the retention mechanism of phenol in mainstream cigarette smoke by cellulose acetate(CA)filters,the phenol filtration efficiency,the phenol distribution in the gas phase and particulate phase during filt...To understand the retention mechanism of phenol in mainstream cigarette smoke by cellulose acetate(CA)filters,the phenol filtration efficiency,the phenol distribution in the gas phase and particulate phase during filtration and the retention characteristics of the filter for both the gas phase and particulate phenol species were investigated.The distribution of particulate bound phenol as a function of the particle size was examined.The ratio of phenol transferring from the particulate phase to the gas phase during smoke flowing through the CA filter were studied.Retention mechanisms for phenol in the gas phase as well as particulate phase phenol in the filter and the phase transition of phenol were proposed.Phenol filtration efficiency of the cigarette filter was calculated based on the proposed retention mechanisms and compared with available experimental data.The results showed that:1)Comparing with nicotine and the other particulate bound smoke constituents,CA filter exhibited a certain retention selectivity for phenol.2)Although phenol was mainly bound to the particulate phase of the cigarette mainstream smoke,about 35% of gas phase phenol was found at the tobacco end of the filter,whilst this dropped to approximately 0 at the mouth end of the filter,mostly by selective chemical adsorption.3)The weighted average smoke particle size and particulate phenol was 0.44 and 0.38 pm,respectively.The filtration efficiency of the filter to particulate phenol was near 40%.4)About 19% of particulate bound phenol transferred to gas phase when smoke passing the filter,and was selectively adsorbed.5)The overall filtration efficiency of the CA filter for phenol in mainstream cigarette smoke was 68.7%,with-7.7% variation compared with experimental data.The results demonstrated the phase transition of phenol during the filtration process and the selective retention with varying particle sizes.Our results showed that the application of CA filter in product designs reduces harmful constituents such as phenolic compounds in mainstream cigarette smoke.展开更多
An improved method was developed for the determination of the four major tobacco-specific nitrosamines(TSNAs) in mainstream cigarette smoke. The new method offers decreased sample preparation and analysis time as comp...An improved method was developed for the determination of the four major tobacco-specific nitrosamines(TSNAs) in mainstream cigarette smoke. The new method offers decreased sample preparation and analysis time as compared to traditional methods. This method uses isotope dilution liquid chromatography coupled with a tandem mass spectrometer with electrospray ionization and is significantly more sensitive than traditional methods. It also shows no evidence of artifactual formation of TSNAs. Sample concentrations were determined for four TSNAs in mainstream smoke using two isotopically labeled TSNAs analogues as internal standards. Mainstream smoke was collected on an industry standard 44-mm Cambridge filter pad, extracted with 0.1 mol/L ammonium acetate, purified by solid-phase extraction, and analyzed without further sample cleanup. The analytical column is a 3.9 mm×150 mm Waters Symmertry Shield RP18 column and volume fraction of the mobile phase is 50% methanol, 50% water containing 0.1% acetic acid. The results show that the linear range is 0.5-100.0 mg/L except for N-nitrosoanabasine (NAB) from 0.25 to 50.0 mg/L. The limits of detection are 0.1 mg/L for N-nitrosonornicotine (NNN), 0.08 mg/L for 4-(methylnitrosamino)-1- (3-py-ridyl)-1-butanone (NNK), 0.05 mg/L for N-nitrosoanatabine (NAT) and 0.06 mg/L for NAB. The recoveries of the four TSNAs are from 90.2% to 105.7%.展开更多
A series of Ag,Cu and Co-doped manganese oxide octahedral molecular sieves(OMS-2) were synthesized and evaluated to remove nitrogen oxides(NOx) from cigarette mainstream smoke.The three kinds of catalysts were added t...A series of Ag,Cu and Co-doped manganese oxide octahedral molecular sieves(OMS-2) were synthesized and evaluated to remove nitrogen oxides(NOx) from cigarette mainstream smoke.The three kinds of catalysts were added to cigarettes for studying the capabilities of reducing NOx from cigarette mainstream smoke.The catalysis and reduction of NO in laboratory were studied.A mechanism for NOx catalytic reduction from burning cigarettes with the catalysts adding to cigarettes was described.The catalysts show excellent catalytic activity for NOx removal,especially the Ag-doped OMS-2 catalyst.0.5%(mass fraction) Ag-doped OMS-2 catalyst has the best ability to remove NOx from cigarette mainstream smoke.The use of Ag-doped OMS-2 as catalyst for removing carcinogenic compounds from cigarette smoke will be an effective strategy to protect the environment and public health.展开更多
[Objective]To explore the effect of expansion temperature on the release of seven kinds of Hoffmann components(CO,NNK,NH3,HCN,BaP,crotonaldehyde and phenol)from the mainstream smoke of cigarette.[Method]The release am...[Objective]To explore the effect of expansion temperature on the release of seven kinds of Hoffmann components(CO,NNK,NH3,HCN,BaP,crotonaldehyde and phenol)from the mainstream smoke of cigarette.[Method]The release amount of seven kinds of Hoffmann components from the mainstream smoke of cigarettes which were prepared from the cut tobacco treated under different expansion temperatures was determined.[Result]Under the same expansion model,the temperature change produced certain impact on the release amount of NH3,phenol and BAP,while had no significant influence on that of CO,NNK,HCN and crotonaldehyde;under CO2 expansion model,the release amount of seven Hoffmann components was small;the reduction of expansion temperature was good for lowering the harmful index of cigarette to a certain extent.[Conclusion]The study provides basis for optimizing the technical parameters of producing less harmful cigarette.展开更多
Cigarette smoking is a particle-related exposure. Studying the characteristics of the particle size distribution of cigarette smoke can aid in providing knowledge of smoke aerosol attributes. We used an electrical low...Cigarette smoking is a particle-related exposure. Studying the characteristics of the particle size distribution of cigarette smoke can aid in providing knowledge of smoke aerosol attributes. We used an electrical low pressure impactor （ELPI） to measure the particle size distribution of mainstream cigarette smoke generated by a smoking machine and provided a continuum of particle sizes of cigarette smoke from a whole cigarette. The results showed that the aerodynamic diameters （D, geometric mean of a channel） of particles ranged from 0.021 to 1.956 ~m, and the number concentrations were on the order of 105-109 cm-3 for different sizes of particles. The particle number of the size category below 0.1 p,m approximated that of the category 0.1-2.0 Ixm, and the particles in the size category of 0.1-2.0 μm contributed extremely heavily to total particulate mass. In addition, the results with small samples indicated that the tar yields normalized per milligram of nicotine showed an approximately linear increase with increasing concentration of total particles.展开更多
基金supported by the Natural Science Foundation of China(No.30972289)Ocean Public Welfare Scientific Research Special Appropriation Project(No.201005020)
文摘This study investigated the removal of heavy metal ions from cigarette mainstream smoke using chitosan.Chitosan of various deacetylation degrees and molecular weights were manually added to cigarette filters in different dosages.The mainstream smoke particulate matter was collected by a Cambridge filter pad,digested by a microwave digestor,and then analyzed for contents of heavy metal ions,including As(III/V),Pb(II),Cd(II),Cr(III/VI) and Ni(II),by graphite furnace atomic absorption spectrometry(GFAAS).The results showed that chitosan had a removal effect on Pb(II),Cd(II),Cr(III/VI) and Ni(II).Of these,the percent removal of Ni(II) was elevated with an increasing dosage of chitosan.Chitosan of a high deace tylation degree exhibited good binding performance toward Cd(II),Cr(III/VI) and Ni(II),though with poor efficiency for Pb(II).Except As(III/V),all the tested metal ions showed similar tendencies in the growing contents with an increasing chitosan molecular weight.Nonetheless,the percent removal of Cr(III/VI) peaked with a chitosan molecular weight of 200 kDa,followed by a dramatic decrease with an increasing chitosan molecular weight.Generally,chitosan had different removal effects on four out of five tested metal ions,and the percent removal of Cd(II),Pb(II),Cr(III/VI) and Ni(II) was approximately 55%,45%,50%,and 16%,respectively.In a word,chitosan used in cigarette filter can remove toxic heavy metal ions in the mainstream smoke,improve cigarette safety,and reduce the harm to smokers.
文摘To understand the retention mechanism of phenol in mainstream cigarette smoke by cellulose acetate(CA)filters,the phenol filtration efficiency,the phenol distribution in the gas phase and particulate phase during filtration and the retention characteristics of the filter for both the gas phase and particulate phenol species were investigated.The distribution of particulate bound phenol as a function of the particle size was examined.The ratio of phenol transferring from the particulate phase to the gas phase during smoke flowing through the CA filter were studied.Retention mechanisms for phenol in the gas phase as well as particulate phase phenol in the filter and the phase transition of phenol were proposed.Phenol filtration efficiency of the cigarette filter was calculated based on the proposed retention mechanisms and compared with available experimental data.The results showed that:1)Comparing with nicotine and the other particulate bound smoke constituents,CA filter exhibited a certain retention selectivity for phenol.2)Although phenol was mainly bound to the particulate phase of the cigarette mainstream smoke,about 35% of gas phase phenol was found at the tobacco end of the filter,whilst this dropped to approximately 0 at the mouth end of the filter,mostly by selective chemical adsorption.3)The weighted average smoke particle size and particulate phenol was 0.44 and 0.38 pm,respectively.The filtration efficiency of the filter to particulate phenol was near 40%.4)About 19% of particulate bound phenol transferred to gas phase when smoke passing the filter,and was selectively adsorbed.5)The overall filtration efficiency of the CA filter for phenol in mainstream cigarette smoke was 68.7%,with-7.7% variation compared with experimental data.The results demonstrated the phase transition of phenol during the filtration process and the selective retention with varying particle sizes.Our results showed that the application of CA filter in product designs reduces harmful constituents such as phenolic compounds in mainstream cigarette smoke.
基金Project(2005JC02) supported by China Tobacco Hunan Industrial Corporation Limited
文摘An improved method was developed for the determination of the four major tobacco-specific nitrosamines(TSNAs) in mainstream cigarette smoke. The new method offers decreased sample preparation and analysis time as compared to traditional methods. This method uses isotope dilution liquid chromatography coupled with a tandem mass spectrometer with electrospray ionization and is significantly more sensitive than traditional methods. It also shows no evidence of artifactual formation of TSNAs. Sample concentrations were determined for four TSNAs in mainstream smoke using two isotopically labeled TSNAs analogues as internal standards. Mainstream smoke was collected on an industry standard 44-mm Cambridge filter pad, extracted with 0.1 mol/L ammonium acetate, purified by solid-phase extraction, and analyzed without further sample cleanup. The analytical column is a 3.9 mm×150 mm Waters Symmertry Shield RP18 column and volume fraction of the mobile phase is 50% methanol, 50% water containing 0.1% acetic acid. The results show that the linear range is 0.5-100.0 mg/L except for N-nitrosoanabasine (NAB) from 0.25 to 50.0 mg/L. The limits of detection are 0.1 mg/L for N-nitrosonornicotine (NNN), 0.08 mg/L for 4-(methylnitrosamino)-1- (3-py-ridyl)-1-butanone (NNK), 0.05 mg/L for N-nitrosoanatabine (NAT) and 0.06 mg/L for NAB. The recoveries of the four TSNAs are from 90.2% to 105.7%.
文摘A series of Ag,Cu and Co-doped manganese oxide octahedral molecular sieves(OMS-2) were synthesized and evaluated to remove nitrogen oxides(NOx) from cigarette mainstream smoke.The three kinds of catalysts were added to cigarettes for studying the capabilities of reducing NOx from cigarette mainstream smoke.The catalysis and reduction of NO in laboratory were studied.A mechanism for NOx catalytic reduction from burning cigarettes with the catalysts adding to cigarettes was described.The catalysts show excellent catalytic activity for NOx removal,especially the Ag-doped OMS-2 catalyst.0.5%(mass fraction) Ag-doped OMS-2 catalyst has the best ability to remove NOx from cigarette mainstream smoke.The use of Ag-doped OMS-2 as catalyst for removing carcinogenic compounds from cigarette smoke will be an effective strategy to protect the environment and public health.
文摘[Objective]To explore the effect of expansion temperature on the release of seven kinds of Hoffmann components(CO,NNK,NH3,HCN,BaP,crotonaldehyde and phenol)from the mainstream smoke of cigarette.[Method]The release amount of seven kinds of Hoffmann components from the mainstream smoke of cigarettes which were prepared from the cut tobacco treated under different expansion temperatures was determined.[Result]Under the same expansion model,the temperature change produced certain impact on the release amount of NH3,phenol and BAP,while had no significant influence on that of CO,NNK,HCN and crotonaldehyde;under CO2 expansion model,the release amount of seven Hoffmann components was small;the reduction of expansion temperature was good for lowering the harmful index of cigarette to a certain extent.[Conclusion]The study provides basis for optimizing the technical parameters of producing less harmful cigarette.
基金supported by the National Natural Science Foundation of China(No.21007094)to Xiang Li
文摘Cigarette smoking is a particle-related exposure. Studying the characteristics of the particle size distribution of cigarette smoke can aid in providing knowledge of smoke aerosol attributes. We used an electrical low pressure impactor （ELPI） to measure the particle size distribution of mainstream cigarette smoke generated by a smoking machine and provided a continuum of particle sizes of cigarette smoke from a whole cigarette. The results showed that the aerodynamic diameters （D, geometric mean of a channel） of particles ranged from 0.021 to 1.956 ~m, and the number concentrations were on the order of 105-109 cm-3 for different sizes of particles. The particle number of the size category below 0.1 p,m approximated that of the category 0.1-2.0 Ixm, and the particles in the size category of 0.1-2.0 μm contributed extremely heavily to total particulate mass. In addition, the results with small samples indicated that the tar yields normalized per milligram of nicotine showed an approximately linear increase with increasing concentration of total particles.
