- Dettagli della rivista
- Formato
- Rivista
- eISSN
- 2719-9509
- Pubblicato per la prima volta
- 01 Jan 1992
- Periodo di pubblicazione
- 4 volte all'anno
- Lingue
- Inglese
Cerca
- Accesso libero
Variability of Peronospora Tabacina A. - An Isoenzyme Study
Pagine: 3 - 13
Astratto
The variability of
- Accesso libero
Chiral-Gas Chromatography-Selected Ion Monitoring-Mass Selective Detection Analysis of Tobacco Materials and Tobacco Smoke
Pagine: 15 - 33
Astratto
A novel method for the detection, separation, and quantification of the optical isomers of nicotine has been developed. The method has been applied to analyse extracts of tobacco seeds, processed tobacco suspensions, reconstituted tobacco sheet materials, individual tobacco varieties, blends of tobaccos, and cigarette smoke condensate. The methodology does not involve any further sample preparation other than that which is normally used to analyse tobacco alkaloids by the modified method of Gordon et al. (73), or the standard FTC smoke analysis routinely performed by most tobacco and smoke analysis laboratories. Near baseline resolution was obtained for enantiomers, yielding a lower detection limit of approximately 2 % d-nicotine in a mixture of d-and l-nicotine. There was essentially no d-nicotine found in any of the tobacco samples. Detectable levels of d-nicotine were found in most of the samples of cigarette smoke condensate when the cigarettes were smoke by the FTC method. The presence of Oriental tobacco in the cigarette appeared to be related to whether d-nicotine was generated in the mainstream cigarette smoke condensate. When the same cigarettes were smoked under a more stressful puffing regime the level of d-nicotine in the smoke did not increase and in some cases the level of d-nicotine decreased. This work supports prior literature that detected and quantified the presence of d-nicotine in cigarette smoke condensate.
- Accesso libero
Chiral-Gas Chromatograpy-Selected Ion Monitoring-Mass Selective Detection Analysis of Secondary Alkaloids in Tobacco and Tobacco Smoke
Pagine: 35 - 42
Astratto
Chiral gas chromatography-mass selective detection has been successfully employed in the analysis of secondary alkaloids in selected tobacco materials and cigarette smoke condensate. No extensive sample preparation is involved. A lower detection limit of ~2 % d-nornicotine, d-anabasine and d-anatabine in a mixture of l and d-isomers was achieved. The levels and the enantiomeric ratios of nicotine, nornicotine, anabasine and anatabine varied in different tobacco types. The enantiomeric ratios of nicotine, anabasine and anatabine in mainstream cigarette condensate also varied but were generally representative of the enantiomeric ratios for the alkaloids found in the leaf. The enantiomeric ratio for nornicotine in mainstream cigarette condensate also varied and was not representative of the enantiomeric ratios for the alkaloids found in the leaf. Preferential decomposition or racemization may account for the differences seen in the yields of isomers of nornicotine transferred to the mainstream smoke condensate. An experiment was conducted to determine if the d-nornicotine present in tobacco contributed to the yield of d-nicotine in mainstream smoke condensate. The results of that experiment indicated that the yield of d-nicotine transferred to mainstream smoke did not change significantly when either large levels of endogenous nornicotine were present in the leaf or when large levels of exogenous levels of d-, l-nornicotine were applied to the tobacco rod prior to smoking. The limiting factor in the production of d-nicotine in mainstream cigarette smoke condensate may be the concentration of methyl radicals present to react. Further work must be conducted to unravel the mechanism involved in the production of d-nicotine in cigarette smoke condensate.
Astratto
In Switzerland approximately 730 ha of tobacco are grown, mainly on small family farms. The main growing area is located in the French speaking part of the country, on altitudes ranging from 400 to 800 m above sea level. Approximately 93 % of the surface is planted with Burley and 7 % with Virginia. The cigarette manufacturers have to buy the whole crop of acceptable quality by law proportionally to their market share in Switzerland, in total approximately 1300-1500 tons per year. The buying organization, named SOTA (Societe cooperative pour l'achat du tabac indigene) has been created by the industry in 1930. It is responsible to buy and distribute the whole crop and finances a small research center with the aim to improve the quality. There is an agreement between the SOTA and the grower's organization FAPTA (Federation suisse des associations de planteurs de tabac) that limits the maximum surface to 730 ha. The price paid to the farmer is fixed by the government and is significantly higher than the world market price. The difference between the price paid to the farmer and the one paid by the industry is compensated by a specific fund which is under supervision of the custom and excise department. Because of several good crops, this system of subsidy became problematic. Therefore a new system of quota has been introduced for the 1997/1998 crop which limits the quantity of tobacco which can be delivered by each farmer.
- Accesso libero
Conference Report - Systemic Acquired Resistance (SAR): A Meeting Organized by the Pesticide Group of the Society of the Chemical Industry, March 10, 1998, London, UK
Pagine: 47 - 48
Astratto
Conference Report Systemic Acquired Resistance (SAR): a meeting organized by the pesticide group of the society of the chemical industry, march 10, 1998, London, UK
- Accesso libero
Letters to the Editor - Tobacco smoke components
Pagine: 49 - 52
Astratto
- Accesso libero
Seminars in Tobacco Science - Particulate Matter, ‘TAR’, Condensate
Pubblicato online: 06 Jan 2015Pagine: 53 - 53