Eliminating carcinogenic pollutants in environment: reducing the tobacco specific nitrosamines level of smoke by zeolite-like calcosilicate

Investigation of exposure biomarkers in human plasma following differing levels of tobacco-specific N-nitrosamines and nicotine in cigarette smoke

Tobacco-specific N-nitrosamines (TSNAs) are strong carcinogens widely found in tobacco products, environmental tobacco smoke, lake, and wastewater. The main objective of this study was to investigate the effects of cigarette smoke with different yields of TSNAs (NNK, NNN, NAT, NAB) and nicotine on the levels of biomarkers of exposure in smokers' plasma. Three hundred healthy volunteers were recruited comprising 60 smokers of each of 3 mg, 8 mg and 10 mg ISO tar yield cigarettes and 60 smokers who smoked 10 mg, 8 mg, and 3 mg for 14 days sequentially and 60 non-smokers. All study participants were male, aged from 21 to 45 years old, and were recruited from a same unit in Hebei, China. We measured the levels of NNAL, NAT, NNN, NAB and cotinine in plasma from 240 smokers and 60 non-smokers using a novel method established by online two-dimensional solid phase extraction-liquid chromatography-tandem mass spectrometry. The results showed that NNAL, NAT, NNN, NAB and cotinine in the plasma of smokers smoking cigarette with low TSNAs and nicotine were lower than that with high TSNAs and nicotine. When smokers switched from higher to lower TSNA yields of cigarettes, their plasma NNAL, NAT, NNN, NAB levels significantly decreased. The plasma concentrations of NNAL were significantly correlated with those of cotinine, NNN, NAT and NAB for smokers (p < 0.001). Similarly, the plasma concentrations of cotinine were significantly correlated with those of NNN, NAT and NAB for smokers (p < 0.001). The plasma NNAL, NAT, NNN, NAB and cotinine levels for smokers were significantly higher than those for non-smokers. These findings suggested that the total NNAL, NNN, NAT, NAB and cotinine in plasma were valid and reliable biomarkers for human exposure to TSNAs and nicotine.

The Effect of Temperature and Time of the Hydrothermal Treatment in the SBA-15 Synthesis Process on the Structure and Textural Properties and the Ability to Reduce the Evolution of Tars in Tobacco Smoking

Different SBA-15 (SBA, Santa Barbara Amorphous) materials were synthetized at different temperature and time during of the hydrothermal treatment. The obtained SBA-15 were characterized by N2 adsorption isotherms, scanning electron microscopy (SEM), X-ray diffraction (DRX), and density in order to establish the influence of these variables on their properties. Mixtures of the obtained catalysts with 3R4F tobacco were prepared and smoked under the ISO 3308 conditions. Temperature of the hydrothermal treatment slightly affects the tars that evolved in the smoking process of the corresponding catalyst tobacco mixtures. Contrarily, the time of the hydrothermal treatment has a marked effect on the reductions of toxic compounds in the smoke. Developed porosity has a positive correlation with the observed tar reduction, whereas the apparent density has a negative correlation with the reduction in toxicity. Moreover, the removal of the supernatant liquors during the hydrothermal treatment does not strongly modify the properties of the materials and may represent an interesting simplification of the process.

Hierarchical Composites to Reduce N-Nitrosamines in Cigarette Smoke

In order to reduce the harmful constituents in cigarette smoke, two hierarchical composites were synthesized. Based on, zeolites HZSM-5 or NaY fragments were introduced into the synthetic system of mesoporous silica SBA-15 or MCM-41 and assembled with the mesoporous materials. These porous composites combine the advantages of micro- and mesoporous materials, and exhibit higher effects than activated carbon on reducing tobacco specific nitrosamines (TSNA) and some vapor phase compounds in smoke.

Novel menthol releaser derived from as-synthesized mesoporous silica

Menthol could be adsorbed in as-synthesized MCM-41 at 373 K, open stored in ambient for 30 days and released at 333 K.

Reduction of tobacco smoke components yield in commercial cigarette brands by addition of HUSY, NaY and Al-MCM-41 to the cigarette rod

The effect of two zeolites, HUSY, NaY and a mesoporous synthesized Al-MCM-41 material on the smoke composition of ten commercial cigarettes brands has been studied. Cigarettes were prepared by mixing the tobacco with the three powdered materials, and the smoke obtained under the ISO conditions was analyzed. Up to 32 compounds were identified and quantified in the gas fraction and 80 in the total particulate matter (TPM) condensed in the cigarettes filters and in the traps located after the mouth end of the cigarettes. Al-MCM-41 is by far the best additive, providing the highest reductions of the yield for most compounds and brands analyzed. A positive correlation was observed among the TPM and nicotine yields with the reduction obtained in nicotine, CO, and most compounds with the three additives. The amount of ashes in additive free basis increases due to the coke deposited on the solids, especially with Al-MCM-41. Nicotine is reduced with Al-MCM-41 by an average of 34.4% for the brands studied (49.5% for the brand where the major reduction was obtained and 18.5 for the brand behaving the worst). CO is reduced by an average of 18.6% (ranging from 10.3 to 35.2% in the different brands).

Selectively reduction of tobacco specific nitrosamines in cigarette smoke by use of nanostructural titanates

In this study, titanate nanosheets, nanotubes, and nanowires, were synthesized by hydrothermal treatment anatase TiO2 in different temperatures. The obtained products are characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron micrograph (TEM) and Brunauer-Emmett-Teller (BET) nitrogen sorption-desorption measurement. Then, the nanostructural titanates were used as additives for selectively reducing tobacco-specific nitrosamines (TNSAs) in mainstream cigarette smoke (CS) for the first time. These nanomaterials exhibited high reduction ability of TSNAs which was related to their intrinsic properties. The N-NO functional group of TSNAs with a negative charge would react with H(+) on the surface of nanomaterials via chemical absorption and can be retained on the surface of the titanates. Among these materials, titanate nanowires (TNW) captured more TNSAs owing to their network structure, which resulted in the selective reduction ratio of TSNAs being improved significantly. Thus, TNW is a useful additive for selectively reducing the TSNAs in CS without changing the cigarette flavor.

A facile synthesis and application of protoporphyrin derivatives on reducing the tobacco specific N-nitroamines levels of smoke

Two protoporphyrin derivatives were prepared by a facile method using inexpensive hemin as starting material. They were added to cigarette filters to reduce the carcinogenic tobacco specific N-nitroamines (TSNAs), especially toward NNK (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone) and NNN (N-nitrosonornicotine) for environment protection and public health. The reduction level of TSNAs was reached to 37.6% from MSS, with greater reductions when more porphyrin was included in the filter. The decrease level for NNK by protoporphyrin derivatives is more effective than NNN. The interaction between protoporphyrin derivatives and TSNAs (NNK and NNN) were investigated by fluorescence spectra and UV-visible titration. The correlation coefficients were 0.978~0.997 and the binding constants was the scope from 1.26 × 103 to 4.04 × 104. The interaction mechanisms between protoporphyrin derivatives and, NNK and NNN are possibly the co-interaction of hydrogen bond binding and strong π–π stacking.

Addition of porphyrins to cigarette filters to reduce the levels of benzo[a]pyrene (B[a]P) and tobacco-specific N-nitrosamines (TSNAs) in mainstream cigarette smoke

Tobacco-specific N-nitrosamines (TSNAs) and benzo[a]pyrene (B[a]P) in mainstream cigarette smoke (MSS) cause smoking-related diseases and environmental pollution. Porphyrins were added to cigarette filters to reduce B[a]P (porphyrins A-E) and TSNAs (porphyrin F) in MSS. The porphyrin-B[a]P and porphyrin F-TSNAs (N'-nitrosoanabasine (NAB), N'-nitrosoanatabine (NAT), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and N-nitrosonornicotine (NNN)) interactions were investigated by fluorescence quenching and UV-visible spectroscopy. The correlation coefficients were 0.987-0.997 (B[a]P) and 0.994-0.999 (TSNAs), and the binding constants were (1.67-5.02) × 10(5) (B[a]P) and 3.42 × 10(3)-1.40 × 10(4) (TSNAs). Up to 36.72% of B[a]P and 46.67% of the TSNAs were eliminated from MSS, with greater reductions when more porphyrin was included in the filter. With the same mass of porphyrin in the filter, the reduction trend for B[a]P by porphyrins A-E was A > B > C > D > E. The reduction trend for TSNAs by porphyrin F was NNN > NAB > NNK > NAT. The porphyrin mode of action is possibly through strong π-π interactions.

Novel phenol capturer derived from the as-synthesized MCM-41

Novel phenol-capturer was prepared by modifying the as-synthesized mesoporous silica MCM-41 with tetraethylenepentamine (TEPA), not only saving the energy and time for removal of template, but also opening the way to utilize the micelles for adsorption. Once the organic modifier was distributed in the template micelle of MCM-41 to form a web within the mesoporous channel, the composite could adsorb more phenols in gas stream than activated carbon for the first time. With an unwanted high adsorption capacity, this mesoporous silica-amine composite represented potential application for trapping phenols, especially in tobacco smoke to protect environment.

Capturing nitrosamines in tobacco-extract solution by hydrophobic mesoporous silica

Adsorption of tobacco-specific nitrosamines (TSNA) by the functionalized MCM-48 mesoporous silica in tobacco-extract solution was studied using batch experiments, in order to explore the new strategy enhancing the efficiency of molecular sieve in the solution with complex composition. The techniques of XRD, N(2) adsorption-desorption at 77K, (29)Si MAS NMR, (27)Al MAS NMR and TG-DSC together with FTIR were used to inspect the mesoporous adsorbents. The hydrophobic character of adsorbent is crucial for the adsorption of TSNA in aqueous solution, and the organic 3-chloropropyltriethoxysilane (CPTES) was employed to functionalize the ordered porous silica through direct co-condensation and post-synthesis grafting methods. Besides, aluminum is also incorporated into the framework of MCM-48 to enhance the adsorption capability of nitrosamines. As the result, about 70% of TSNA can be removed by the chloropropyl-modified Al-containing mesoporous silica, obviously exceeded that by activated carbon, offering the new efficient adsorbents for environment protection.