Summary Tobacco-specific nitrosamines (TSNAs) including nitrosoanabasine (NAB), nitrosoanatabine (NAT), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and nitrosonornicotine (NNN) are naturally present at trace levels in tobacco. During tobacco processing, preparation of expanded tobacco, and when tobacco is used in heat-not-burn type cigarettes, the tobacco is exposed to different degrees of heat. Heating of tobacco has been reported in the literature to increase the level of TSNAs. Since the increase of TSNAs in heated tobacco is still not well understood, the present study evaluated TSNA levels in six types of tobacco as a function of moderate heat exposure. These tobaccos included: flue-cured lower stalk, flue-cured upper stalk (US), Burley lower stalk, Burley upper stalk (US), and two Oriental blends (Turkey, Greece, Bulgaria, Northern Republic Macedonia). Heating was performed in sealed glass tubes at oven temperatures of 100 °C, 150 °C, 200 °C, and 250 °C for time intervals of 2 min and 5 min. The temperatures inside the glass tubes were lower than the targets and were monitored separately as a function of glass tube heating. The study showed no meaningful differences within tobacco type (by stalk position) but showed considerable differences in the levels of TSNAs between different tobaccos, with the Burley tobaccos having the highest levels, and the Orientals the lowest. For all tobacco types, TSNAs increase to some extent when temperature increases. For 2-min heating, the increase in TSNAs is relatively small up to about 200 °C, but the levels almost double when the oven temperature increases to 250 °C. For 5-min heating, the increase in TSNAs starts at about 150 °C with a maximum at 200 °C which can reach more than double the initial TSNA level. Longer heating at 250 °C (5 min) starts to cause TSNAs decomposition and the levels are reduced.
{"title":"Variations of TSNA Levels in Tobaccos Upon Heating at Moderate Temperatures","authors":"S. Moldoveanu, Marlene Adams, F. K. St.Charles","doi":"10.2478/cttr-2020-0009","DOIUrl":"https://doi.org/10.2478/cttr-2020-0009","url":null,"abstract":"Summary Tobacco-specific nitrosamines (TSNAs) including nitrosoanabasine (NAB), nitrosoanatabine (NAT), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and nitrosonornicotine (NNN) are naturally present at trace levels in tobacco. During tobacco processing, preparation of expanded tobacco, and when tobacco is used in heat-not-burn type cigarettes, the tobacco is exposed to different degrees of heat. Heating of tobacco has been reported in the literature to increase the level of TSNAs. Since the increase of TSNAs in heated tobacco is still not well understood, the present study evaluated TSNA levels in six types of tobacco as a function of moderate heat exposure. These tobaccos included: flue-cured lower stalk, flue-cured upper stalk (US), Burley lower stalk, Burley upper stalk (US), and two Oriental blends (Turkey, Greece, Bulgaria, Northern Republic Macedonia). Heating was performed in sealed glass tubes at oven temperatures of 100 °C, 150 °C, 200 °C, and 250 °C for time intervals of 2 min and 5 min. The temperatures inside the glass tubes were lower than the targets and were monitored separately as a function of glass tube heating. The study showed no meaningful differences within tobacco type (by stalk position) but showed considerable differences in the levels of TSNAs between different tobaccos, with the Burley tobaccos having the highest levels, and the Orientals the lowest. For all tobacco types, TSNAs increase to some extent when temperature increases. For 2-min heating, the increase in TSNAs is relatively small up to about 200 °C, but the levels almost double when the oven temperature increases to 250 °C. For 5-min heating, the increase in TSNAs starts at about 150 °C with a maximum at 200 °C which can reach more than double the initial TSNA level. Longer heating at 250 °C (5 min) starts to cause TSNAs decomposition and the levels are reduced.","PeriodicalId":10723,"journal":{"name":"Contributions to Tobacco & Nicotine Research","volume":"2014 1","pages":"84 - 96"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86775017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Jakab, Z. Sebestyén, B. Babinszki, E. Barta-Rajnai, Z. Czégény, James Nicol, P. Clayton, Chuan Liu
Summary The thermo-oxidative decomposition of lovage (Levisticum officinale) and davana (Artemisia pallens) essential oils has been studied by pyrolysis-gas chromatography/mass spectrometry in 9% oxygen and 91% nitrogen atmosphere at 300 °C to simulate low-temperature tobacco heating conditions. Both lovage and davana oils contain numerous chemical substances; the main components of both oils are various oxygen-containing compounds. Isobenzofuranones are the most important constituents of lovage oil, and their relative intensity changed significantly during oxidative pyrolysis. (Z)-ligustilide underwent two kinds of decomposition reactions: an aromatization reaction resulting in the formation of butylidenephthalide and the scission of the lactone ring with the elimination of carbon dioxide or carbon monoxide. Davanone is the main component of davana oil, which did not decompose considerably during low-temperature oxidative pyrolysis. However, the relative yield of the second most intensive component, bicyclogermacrene, reduced markedly due to bond rearrangement reactions. Davana ether underwent oxidation reactions leading to the formation of various furanic compounds. The changes in the composition of both essential oils could be interpreted in terms of bond splitting, intramolecular rearrangement mechanisms and oxidation reactions of several constituents during low-temperature oxidative pyrolysis. The applied thermo-oxidative method was found to be suitable to study the stability of the essential oils and monitor the decomposition products under simulated tobacco heating conditions. In spite of the complicated composition of the essential oils, no evidence for interaction between the oil components was found. [Beitr. Tabakforsch. Int. 29 (2020) 27–43]
{"title":"Thermo-Oxidative Decomposition of Lovage (Levisticum officinale) and Davana (Artemisia pallens) Essential Oils under Simulated Tobacco Heating Product Conditions","authors":"E. Jakab, Z. Sebestyén, B. Babinszki, E. Barta-Rajnai, Z. Czégény, James Nicol, P. Clayton, Chuan Liu","doi":"10.2478/cttr-2020-0004","DOIUrl":"https://doi.org/10.2478/cttr-2020-0004","url":null,"abstract":"Summary The thermo-oxidative decomposition of lovage (Levisticum officinale) and davana (Artemisia pallens) essential oils has been studied by pyrolysis-gas chromatography/mass spectrometry in 9% oxygen and 91% nitrogen atmosphere at 300 °C to simulate low-temperature tobacco heating conditions. Both lovage and davana oils contain numerous chemical substances; the main components of both oils are various oxygen-containing compounds. Isobenzofuranones are the most important constituents of lovage oil, and their relative intensity changed significantly during oxidative pyrolysis. (Z)-ligustilide underwent two kinds of decomposition reactions: an aromatization reaction resulting in the formation of butylidenephthalide and the scission of the lactone ring with the elimination of carbon dioxide or carbon monoxide. Davanone is the main component of davana oil, which did not decompose considerably during low-temperature oxidative pyrolysis. However, the relative yield of the second most intensive component, bicyclogermacrene, reduced markedly due to bond rearrangement reactions. Davana ether underwent oxidation reactions leading to the formation of various furanic compounds. The changes in the composition of both essential oils could be interpreted in terms of bond splitting, intramolecular rearrangement mechanisms and oxidation reactions of several constituents during low-temperature oxidative pyrolysis. The applied thermo-oxidative method was found to be suitable to study the stability of the essential oils and monitor the decomposition products under simulated tobacco heating conditions. In spite of the complicated composition of the essential oils, no evidence for interaction between the oil components was found. [Beitr. Tabakforsch. Int. 29 (2020) 27–43]","PeriodicalId":10723,"journal":{"name":"Contributions to Tobacco & Nicotine Research","volume":"86 1","pages":"27 - 43"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81452335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. John, S. Coburn, Chuan Liu, J. Mcaughey, D. Mariner, K. McAdam, I. Bakos, S. Dóbé
Summary A diffusion denuder apparatus has been used to investigate the gas-particle partitioning of formaldehyde, acetaldehyde, acrolein and crotonaldehyde in cigarette mainstream smoke (MS), compounds that are of interest owing to their toxicity and near quantitative retention in the body during cigarette smoking. Formaldehyde showed the best performance in denuder experiments with simple aldehyde-air mixtures owing to the relatively fast rate of the heterogeneous reaction formaldehyde(g) + dinitrophenylhydrazine(s) → hydrazone(s). Analysis with the Gormley-Kennedy equation revealed that formaldehyde denuder removal approached, but did not attain, complete efficiency even under optimized operational conditions. Acetaldehyde, acrolein and crotonaldehyde were trapped with considerably lower efficiency than formaldehyde under the denuder conditions used, and more effective denuder wall coatings would be required to examine gas-particle partitioning of these other carbonyls. The proportion of formaldehyde in the smoke particulate phase initially entering the denuder was > 99%, but loss of formaldehyde from the smoke particles was relatively rapid leading to 35%–61% deposition over the denuder length. The temperature dependence of formaldehyde deposition in the denuder was well predicted using Henry's law constant for aqueous formaldehyde solutions. These observed properties of formaldehyde are primarily due to reversible reactions of formaldehyde with water in cigarette smoke leading to the much less volatile species methanediol, its oligomers and hydrate. These data suggest that cigarette smoke inhalation is likely to expose the deeper-lung generations of smokers to greater relative formaldehyde exposure, and greater genotoxic risk at those generations than might occur through inhalation of formaldehyde vapour alone. Risk assessments of formaldehyde in cigarette smoke should be updated to recognise this modified risk profile.
{"title":"Gas-Particle Partitioning of Formaldehyde in Mainstream Cigarette Smoke","authors":"E. John, S. Coburn, Chuan Liu, J. Mcaughey, D. Mariner, K. McAdam, I. Bakos, S. Dóbé","doi":"10.2478/cttr-2020-0002","DOIUrl":"https://doi.org/10.2478/cttr-2020-0002","url":null,"abstract":"Summary A diffusion denuder apparatus has been used to investigate the gas-particle partitioning of formaldehyde, acetaldehyde, acrolein and crotonaldehyde in cigarette mainstream smoke (MS), compounds that are of interest owing to their toxicity and near quantitative retention in the body during cigarette smoking. Formaldehyde showed the best performance in denuder experiments with simple aldehyde-air mixtures owing to the relatively fast rate of the heterogeneous reaction formaldehyde(g) + dinitrophenylhydrazine(s) → hydrazone(s). Analysis with the Gormley-Kennedy equation revealed that formaldehyde denuder removal approached, but did not attain, complete efficiency even under optimized operational conditions. Acetaldehyde, acrolein and crotonaldehyde were trapped with considerably lower efficiency than formaldehyde under the denuder conditions used, and more effective denuder wall coatings would be required to examine gas-particle partitioning of these other carbonyls. The proportion of formaldehyde in the smoke particulate phase initially entering the denuder was > 99%, but loss of formaldehyde from the smoke particles was relatively rapid leading to 35%–61% deposition over the denuder length. The temperature dependence of formaldehyde deposition in the denuder was well predicted using Henry's law constant for aqueous formaldehyde solutions. These observed properties of formaldehyde are primarily due to reversible reactions of formaldehyde with water in cigarette smoke leading to the much less volatile species methanediol, its oligomers and hydrate. These data suggest that cigarette smoke inhalation is likely to expose the deeper-lung generations of smokers to greater relative formaldehyde exposure, and greater genotoxic risk at those generations than might occur through inhalation of formaldehyde vapour alone. Risk assessments of formaldehyde in cigarette smoke should be updated to recognise this modified risk profile.","PeriodicalId":10723,"journal":{"name":"Contributions to Tobacco & Nicotine Research","volume":"14 1","pages":"2 - 20"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85025498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nan Deng, S. Ehlert, Huapeng Cui, F. Xie, Jan Heide, Bin Li, Chuan Liu, K. McAdam, A. Walte, R. Zimmermann
Summary Background Combustion as well as pyrolysis of tobacco greatly affect the type and levels of toxicants in cigarette smoke. We previously developed an approach to combine simultaneous temperature and pressure measurements with fast in-situ microprobe chemical sampling inside a burning cigarette, producing a series of temperature and gas-flow velocity maps that characterize this dynamic system in response to externally applied air flow. Aim Two cigarette types differing only in diameter were puffed under ISO 3308 and Health Canada Intense (HCI) regimes to further understand the dynamic interaction of air flow and cigarette design parameters on tobacco combustion and pyrolysis by applying the thermophysical and thermo-chemical mapping approach. Methods Three types of sampling probes were inserted, which are thermocouple arrays for gas-phase temperature, quartz tubes for pressure measurement, and a heated sampling microprobe coupled to a single-photon soft ionisation mass spectrometer for chemical analysis. Two kinds of similarly constructed cigarettes with the same blend were analysed: superslim (17 mm circumference) and king-size (24 mm circumference). Synchronization among the sampled signals was achieved by mapping two probes (e.g., temperature/chemistry or temperature/pressure) at a time. The physical and chemical events were visualised and compared between the cigarettes and puffing regimes. Results A series of temperature, pressure, and chemical maps were obtained for the superslim and king-size cigarettes under ISO and HCI conditions. The pressure in the burning cigarette was higher in the superslim cigarette, and the temperature distribution differed between the two cigarette formats. As expected, temperatures and pressures were higher under HCI puffing than under ISO puffing for both cigarette formats. Thermochemical maps for e.g., benzene and nitric oxide formation were qualitatively similar between the superslim and king-size cigarettes. For other substances the distribution was markedly different. Conclusion The application of multi-probe in-situ chemical sampling is suitable to analyse highly dynamic combustion and pyrolysis processes occurring inside the two types of cigarettes. Ultimately, a direct comparison of cigarette circumferences on the complex combustion processes and formation of smoke constituents was achieved. [Beitr. Tabakforsch. Int. 29 (2020) 44–54]
{"title":"Integration of Time and Spatially Resolved In-Situ Temperature and Pressure Measurements With Soft Ionisation Mass Spectrometry Inside Burning Superslim and King-Size Cigarettes","authors":"Nan Deng, S. Ehlert, Huapeng Cui, F. Xie, Jan Heide, Bin Li, Chuan Liu, K. McAdam, A. Walte, R. Zimmermann","doi":"10.2478/cttr-2020-0005","DOIUrl":"https://doi.org/10.2478/cttr-2020-0005","url":null,"abstract":"Summary Background Combustion as well as pyrolysis of tobacco greatly affect the type and levels of toxicants in cigarette smoke. We previously developed an approach to combine simultaneous temperature and pressure measurements with fast in-situ microprobe chemical sampling inside a burning cigarette, producing a series of temperature and gas-flow velocity maps that characterize this dynamic system in response to externally applied air flow. Aim Two cigarette types differing only in diameter were puffed under ISO 3308 and Health Canada Intense (HCI) regimes to further understand the dynamic interaction of air flow and cigarette design parameters on tobacco combustion and pyrolysis by applying the thermophysical and thermo-chemical mapping approach. Methods Three types of sampling probes were inserted, which are thermocouple arrays for gas-phase temperature, quartz tubes for pressure measurement, and a heated sampling microprobe coupled to a single-photon soft ionisation mass spectrometer for chemical analysis. Two kinds of similarly constructed cigarettes with the same blend were analysed: superslim (17 mm circumference) and king-size (24 mm circumference). Synchronization among the sampled signals was achieved by mapping two probes (e.g., temperature/chemistry or temperature/pressure) at a time. The physical and chemical events were visualised and compared between the cigarettes and puffing regimes. Results A series of temperature, pressure, and chemical maps were obtained for the superslim and king-size cigarettes under ISO and HCI conditions. The pressure in the burning cigarette was higher in the superslim cigarette, and the temperature distribution differed between the two cigarette formats. As expected, temperatures and pressures were higher under HCI puffing than under ISO puffing for both cigarette formats. Thermochemical maps for e.g., benzene and nitric oxide formation were qualitatively similar between the superslim and king-size cigarettes. For other substances the distribution was markedly different. Conclusion The application of multi-probe in-situ chemical sampling is suitable to analyse highly dynamic combustion and pyrolysis processes occurring inside the two types of cigarettes. Ultimately, a direct comparison of cigarette circumferences on the complex combustion processes and formation of smoke constituents was achieved. [Beitr. Tabakforsch. Int. 29 (2020) 44–54]","PeriodicalId":10723,"journal":{"name":"Contributions to Tobacco & Nicotine Research","volume":"17 1","pages":"44 - 54"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74705461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Summary The present study evaluated the in vitro extraction of benzo[a]pyrene (BaP) from moist snuff into water and into artificial saliva. A similar, previous study evaluated the levels of BaP that remained in the moist snuff after the extraction but did not measure the levels of BaP in the water or saliva extract. The previous study showed that the remaining levels of BaP in the solid material were between 96.3% and 109.6% relative to the initial level of BaP, when the snuff was washed with water and between 99.4% and 108.3% from the initial level of BaP, when the snuff was washed with both saliva and water. Nine moist snuff samples (eight being the same brands as evaluated in the previous study) were analyzed in the present study. Several improvements were made compared to the previous study regarding the extraction conditions. The extraction was performed for 1 h at 37 °C, using a mechanical agitator. The previous study used a commercially available artificial saliva which had an adjusted pH but did not contain enzymes or salts. This saliva was replaced with complete artificial saliva containing salts, mucin and enzymes. The results indicated that the level of BaP extracted in 100 mL water from 5 g of moist snuff at 37 °C ranged between 1.0% and 1.7% of the initial level present in tobacco. For artificial saliva, the extracted level of BaP was between 2% and 3.9% from the initial level, depending on the moist snuff brand. Although the BaP level extracted from the moist snuff with artificial saliva remained very low, the surfactant character of artificial saliva increased BaP extraction relative to water by a factor of approximately two. This study supports the previous reported finding that the vast majority of BaP in moist snuff is not extracted in water or artificial saliva.
{"title":"Extraction of Benzo[a]pyrene from Moist Snuff with Water or Artificial Saliva (Part 2)","authors":"S. Moldoveanu, Andrew Harrison","doi":"10.2478/cttr-2020-0003","DOIUrl":"https://doi.org/10.2478/cttr-2020-0003","url":null,"abstract":"Summary The present study evaluated the in vitro extraction of benzo[a]pyrene (BaP) from moist snuff into water and into artificial saliva. A similar, previous study evaluated the levels of BaP that remained in the moist snuff after the extraction but did not measure the levels of BaP in the water or saliva extract. The previous study showed that the remaining levels of BaP in the solid material were between 96.3% and 109.6% relative to the initial level of BaP, when the snuff was washed with water and between 99.4% and 108.3% from the initial level of BaP, when the snuff was washed with both saliva and water. Nine moist snuff samples (eight being the same brands as evaluated in the previous study) were analyzed in the present study. Several improvements were made compared to the previous study regarding the extraction conditions. The extraction was performed for 1 h at 37 °C, using a mechanical agitator. The previous study used a commercially available artificial saliva which had an adjusted pH but did not contain enzymes or salts. This saliva was replaced with complete artificial saliva containing salts, mucin and enzymes. The results indicated that the level of BaP extracted in 100 mL water from 5 g of moist snuff at 37 °C ranged between 1.0% and 1.7% of the initial level present in tobacco. For artificial saliva, the extracted level of BaP was between 2% and 3.9% from the initial level, depending on the moist snuff brand. Although the BaP level extracted from the moist snuff with artificial saliva remained very low, the surfactant character of artificial saliva increased BaP extraction relative to water by a factor of approximately two. This study supports the previous reported finding that the vast majority of BaP in moist snuff is not extracted in water or artificial saliva.","PeriodicalId":10723,"journal":{"name":"Contributions to Tobacco & Nicotine Research","volume":"333 1","pages":"21 - 26"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73894494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Richard Baker died at Easter 2007 after a very short illness. It is sad that he died so soon after his retirement from the British American Tobacco Company at the end of 2005, and just as he was beginning to enjoy his new life, even though tobacco science still had a part to play. In 2006 Richard received the Tobacco Science Research Conference Lifetime Achievement Award, and at this time Thomas Perfetti, in this journal, described his distinguished scientific career in some detail. I will not repeat the list of these remarkable achievements, but can only add that he may well be the only scientist ever to be awarded the ultimate research degree, a D. Sc., by a British University for research activities while working for a tobacco company. Bearing in mind anti-tobacco sentiment this was a breath-taking achievement. Richard joined B.A.T. in 1971 and came to live quite near us on the outskirts of Southampton. We got to know Richard and Jackie well. Being a few years older several of the younger Thornton's then acted as baby-sitters as the younger Baker's appeared on the scene. Richard's enthusiasm for jogging and long-distance running was well known. As he jogged by the entrance to my house on foggy mornings he became a well-known health hazard, both to himself and to me. Richard's interests also included local politics and schools and indicated his great interest in people and their well-being. He was a kind and thoughtful colleague. When we moved house in 1976 Richard and Jackie sent us a good luck card, repeated in 1994 when we moved, briefly and spectacularly, to New Delhi. Richard's last years were evidently as full as ever, and he was still publishing scientific papers in his role as a Consultant. He was close to his family and children. Grandchildren, of whom he was very fond, had arrived. Richard and Jackie had also acquired a holiday home in their beloved Lake District in N.W. England. I, and everyone who met him, will have fond recollections of Richard as a delightful person and as an outstanding scientist, and above all we would like Jackie to know how we regarded him.
{"title":"Obituary: Dr. Richard Roland Baker","authors":"R. Thornton","doi":"10.2478/CTTR-2013-0839","DOIUrl":"https://doi.org/10.2478/CTTR-2013-0839","url":null,"abstract":"Abstract Richard Baker died at Easter 2007 after a very short illness. It is sad that he died so soon after his retirement from the British American Tobacco Company at the end of 2005, and just as he was beginning to enjoy his new life, even though tobacco science still had a part to play. In 2006 Richard received the Tobacco Science Research Conference Lifetime Achievement Award, and at this time Thomas Perfetti, in this journal, described his distinguished scientific career in some detail. I will not repeat the list of these remarkable achievements, but can only add that he may well be the only scientist ever to be awarded the ultimate research degree, a D. Sc., by a British University for research activities while working for a tobacco company. Bearing in mind anti-tobacco sentiment this was a breath-taking achievement. Richard joined B.A.T. in 1971 and came to live quite near us on the outskirts of Southampton. We got to know Richard and Jackie well. Being a few years older several of the younger Thornton's then acted as baby-sitters as the younger Baker's appeared on the scene. Richard's enthusiasm for jogging and long-distance running was well known. As he jogged by the entrance to my house on foggy mornings he became a well-known health hazard, both to himself and to me. Richard's interests also included local politics and schools and indicated his great interest in people and their well-being. He was a kind and thoughtful colleague. When we moved house in 1976 Richard and Jackie sent us a good luck card, repeated in 1994 when we moved, briefly and spectacularly, to New Delhi. Richard's last years were evidently as full as ever, and he was still publishing scientific papers in his role as a Consultant. He was close to his family and children. Grandchildren, of whom he was very fond, had arrived. Richard and Jackie had also acquired a holiday home in their beloved Lake District in N.W. England. I, and everyone who met him, will have fond recollections of Richard as a delightful person and as an outstanding scientist, and above all we would like Jackie to know how we regarded him.","PeriodicalId":10723,"journal":{"name":"Contributions to Tobacco & Nicotine Research","volume":"69 1","pages":"316 - 316"},"PeriodicalIF":0.0,"publicationDate":"2007-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84069188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A mathematical model on the temperature and oxygen profiles for the tobacco warehouse aging process was formulated and solved by numeric analysis. The model parameters were obtained using the non-linear regression method by fitting several years measured temperatures to the model. The R square value between measured and calculated tobacco temperatures in warehouse aging process are all over 0.95. The proposed model can be used to predict the tobacco hogshead temperature profile at different time and positions with ambient temperature, tobacco moisture contents and pH. At the same time, the model also predicts the oxygen profile in the hogshead. The effects of the ambient temperature, pH, void fraction, the reaction active energy, oxygen diffusivity, and the oxygen consumption rate constant on the temperature profile were studied.
{"title":"A Model for the Prediction of Tobacco Temperature and Oxygen Profiles in Warehouse Aging Process","authors":"Y. Zheng, J. Chipley, A. Dow, C. Midgett","doi":"10.2478/CTTR-2013-0842","DOIUrl":"https://doi.org/10.2478/CTTR-2013-0842","url":null,"abstract":"Abstract A mathematical model on the temperature and oxygen profiles for the tobacco warehouse aging process was formulated and solved by numeric analysis. The model parameters were obtained using the non-linear regression method by fitting several years measured temperatures to the model. The R square value between measured and calculated tobacco temperatures in warehouse aging process are all over 0.95. The proposed model can be used to predict the tobacco hogshead temperature profile at different time and positions with ambient temperature, tobacco moisture contents and pH. At the same time, the model also predicts the oxygen profile in the hogshead. The effects of the ambient temperature, pH, void fraction, the reaction active energy, oxygen diffusivity, and the oxygen consumption rate constant on the temperature profile were studied.","PeriodicalId":10723,"journal":{"name":"Contributions to Tobacco & Nicotine Research","volume":"51 1","pages":"358 - 364"},"PeriodicalIF":0.0,"publicationDate":"2007-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84645544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This paper presents the findings on a quantitative evaluation of carbonyl levels in exhaled cigarette smoke from human subjects. The cigarettes evaluated include products with 5.0 mg ‘tar’, 10.6 mg ‘tar’ and 16.2 mg ‘tar’, where ‘tar’ is defined as the weight of total wet particulate matter (TPM) minus the weight of nicotine and water, and the cigarettes are smoked following U.S. Federal Trade Commission (FTC) recommendations. The measured levels of carbonyls in the exhaled smoke were compared with calculated yields of carbonyls in the inhaled smoke and a retention efficiency was obtained. The number of human subjects included a total of ten smokers for the 10.6 mg ‘tar’, five for the 16.2 mg ‘tar’, and five for the 5.0 mg ‘tar’ product, each subject smoking three cigarettes. The analyzed carbonyl compounds included several aldehydes (formaldehyde, acetaldehyde, acrolein, propionaldehyde, crotonaldehyde and n-butyraldehyde), and two ketones (acetone and 2-butanone). The smoke collection from the human subjects was vacuum assisted. Exhaled smoke was collected on Cambridge pads pretreated with a solution of dinitrophenylhydrazine (DNPH) followed by high performance liquid chromatography (HPLC) analysis of the dinitrophenylhydrazones of the carbonyl compounds. The cigarette butts from the smokers were collected and analyzed for nicotine. The nicotine levels for the cigarette butts from the smokers were used to calculate the level of carbonyls in the inhaled smoke, based on calibration curves. These were generated separately by analyzing the carbonyls in smoke and the nicotine in the cigarette butts obtained by machine smoking under different puffing regimes. The comparison of the level of carbonyl compounds in exhaled smoke with that from the inhaled smoke showed high retention of all the carbonyls. The retention of aldehydes was above 95% for all three different ‘tar’ levels cigarettes. The ketones were retained with a slightly lower efficiency. Acetone was retained in the range of 90% to 95%. The retention for 2-butanone showed a larger scatter compared to other results but it also appeared to be slightly less absorbed than the aldehydes, with an average retention around 95%. The retention of acetaldehyde and acetone by human smokers was previously reported in literature and the findings from this study are in very good agreement with these result.
{"title":"Determination of Carbonyl Compounds in Exhaled Cigarette Smoke","authors":"S. Moldoveanu, W. Coleman, J. Wilkins","doi":"10.2478/CTTR-2013-0841","DOIUrl":"https://doi.org/10.2478/CTTR-2013-0841","url":null,"abstract":"Abstract This paper presents the findings on a quantitative evaluation of carbonyl levels in exhaled cigarette smoke from human subjects. The cigarettes evaluated include products with 5.0 mg ‘tar’, 10.6 mg ‘tar’ and 16.2 mg ‘tar’, where ‘tar’ is defined as the weight of total wet particulate matter (TPM) minus the weight of nicotine and water, and the cigarettes are smoked following U.S. Federal Trade Commission (FTC) recommendations. The measured levels of carbonyls in the exhaled smoke were compared with calculated yields of carbonyls in the inhaled smoke and a retention efficiency was obtained. The number of human subjects included a total of ten smokers for the 10.6 mg ‘tar’, five for the 16.2 mg ‘tar’, and five for the 5.0 mg ‘tar’ product, each subject smoking three cigarettes. The analyzed carbonyl compounds included several aldehydes (formaldehyde, acetaldehyde, acrolein, propionaldehyde, crotonaldehyde and n-butyraldehyde), and two ketones (acetone and 2-butanone). The smoke collection from the human subjects was vacuum assisted. Exhaled smoke was collected on Cambridge pads pretreated with a solution of dinitrophenylhydrazine (DNPH) followed by high performance liquid chromatography (HPLC) analysis of the dinitrophenylhydrazones of the carbonyl compounds. The cigarette butts from the smokers were collected and analyzed for nicotine. The nicotine levels for the cigarette butts from the smokers were used to calculate the level of carbonyls in the inhaled smoke, based on calibration curves. These were generated separately by analyzing the carbonyls in smoke and the nicotine in the cigarette butts obtained by machine smoking under different puffing regimes. The comparison of the level of carbonyl compounds in exhaled smoke with that from the inhaled smoke showed high retention of all the carbonyls. The retention of aldehydes was above 95% for all three different ‘tar’ levels cigarettes. The ketones were retained with a slightly lower efficiency. Acetone was retained in the range of 90% to 95%. The retention for 2-butanone showed a larger scatter compared to other results but it also appeared to be slightly less absorbed than the aldehydes, with an average retention around 95%. The retention of acetaldehyde and acetone by human smokers was previously reported in literature and the findings from this study are in very good agreement with these result.","PeriodicalId":10723,"journal":{"name":"Contributions to Tobacco & Nicotine Research","volume":"49 1","pages":"346 - 357"},"PeriodicalIF":0.0,"publicationDate":"2007-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88748131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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