- Dettagli della rivista
- Pubblicato per la prima volta
- 01 Jan 1992
- Periodo di pubblicazione
- 4 volte all'anno
- Accesso libero
Pagine: 131 - 146
We developed an internal standard-based method to analyze the vapor phase components of mainstream smoke. This method collects vapor phase components from sample cigarettes, which are smoked by a linear automatic smoking machine in a sampling bag. An internal standard gas was introduced to the bag. A 6-port valve with a 2-ml sampling loop was placed between the vapor phase smoke outlet of the smoking machine and the bag to regulate the volume of the internal standard. The mixed gas sample was then introduced, by an automatic injection device developed in-house, to a gas chromatograph (GC) for ten successive analyses. The sample in the bag was analyzed every two hours to assess the time serial changes of vapor phase smoke components as well as of the internal standard. After 18 hours, in the tenth analysis, the amounts of 37 vapor phase components decreased by less than 5 % from those in the first analysis. The repeatability of the sample analysis was assessed and 45 vapor phase components had coefficients of variation of less than 5 %. The overall reproducibility of this method including tobacco samples and instruments was also assessed using five other sampling bags and achieved coefficients of variation of less than 6 % for 42 vapor phase components. The advantages of this method include capability to handle 10 tobacco samples in a serial manner, capability to collect both the vapor phase and semivolatile components, and precise, easy and continuous component analyses. We also present the results of multivariate analyses for the vapor phase and semivolatile components from 59 sample cigarettes.
- Accesso libero
Pagine: 147 - 163
In order to understand the behaviour of tobacco additives in the burning cigarette it is important to know whether they transfer intact to the smoke or whether there is any decomposition during smoking. There are practical problems in comparing the chemical analysis of whole smoke from cigarettes with and without additives. Changes to the smoke chemistry may be insignificant in analytical terms and therefore missed from a general scan. Targeted analysis of key components potentially overcomes this concern, but has the drawback of being expensive in terms of time and analytical resources. Pyrolysis-GC-MS is an attractive solution in that it potentially enables the effects of combustion of a single material to be studied in isolation. However, it is not entirely valid to base an assessment of a material on a pyrolysis experiment alone unless the results can be demonstrably related to the cigarette smoke chemistry. The variables that affect the outcome of combustion are temperature, rate of change of temperature, oxygen concentration and chemical environment (matrix and gas phase). The key to this work has been in performing pyrolysis experiments under a range of different conditions and relating the experimental conditions to those within the burning zone of the cigarette to give a prediction of smoke chemistry. To test the theory in practise, the transfer and the extent of degradation of anisole, p-anisaldehyde, benzaldehyde, isoamylisovalerate, methyl trans-cinnamate and vanillin within a burning cigarette were investigated using this pyrolysis method. Pyrolyses were undertaken on each additive at 14 sets of pyrolysis conditions: temperatures between 200°C and 700°C in 2 % and 10 % oxygen, and at 800°C and 900°C in 2 % oxygen. By monitoring the presence of the intact additive in the volatile components from the pyrolysis, the temperature at which the additive is likely to transfer to the smoke was determined. By monitoring the decomposition products at temperatures up to this transfer temperature, the extent and products of decomposition likely from the additive were estimated. The pyrolysis predictions were compared with results from a previous study involving adding 14C-analogues of the materials to cigarettes and measuring the resultant radioactive species in the smoke. The results from the pyrolysis experiments lead us to make the following predictions: Anisole, isoamylisovalerate and vanillin will transfer intact to the smoke at 200°C. p-Anisaldehyde and methyl trans-cinnamate are likely to transfer to the smoke at a higher temperature of around 400°C leading to some decomposition/oxidation (3 % and 1 %, respectively). Benzaldehyde is likely to transfer to the smoke at 200°C, but at this temperature a significant amount (~26 %) oxidises to benzoic acid. Both compounds appear resilient to further degradation at higher temperatures. These levels of transfer were found to be consistent with smoke chemistry data.
- Accesso libero
Physical Dimensions and Tar and Nicotine Yields of Fine-cut Smoking Articles Rolled by German Consumers
Pagine: 165 - 174
In 1994, the European Smoking Tobacco Association (ESTA) commissioned and reported a study undertaken in the Netherlands to determine the making habits of roll-your-own smokers. The study included laboratory smoking of the collected smoking articles for the determination of tar and nicotine. In 1997, ESTA commissioned a similar study for Germany involving German fine-cut smokers. This paper reviews the data produced from the German study and compares the data with that produced in the Netherlands. An independent market research agency recruited known smokers of fine-cut tobacco. They were given the most popular brand of tobacco and the most popular brand of booklet paper. The consumers were instructed to make a fine-cut smoking article for testing each time they wanted to smoke. These smoking articles were placed in protective tins and collected by the research agency for analysis. An independent laboratory in Germany undertook the smoking and analysis. This study shows that a German roll-your-own smoker uses an average of 830 mg tobacco and makes a product that is 7.6 mm in diameter. German booklet paper is slightly shorter than Dutch paper. German products are more cylindrical than Dutch products and this probably accounts for the much reduced variability of German products compared with Dutch products. The mean tar yield of these articles was 12 mg and the mean nicotine yield was 0.9 mg.