- Zeitschriftendaten
- Format
- Zeitschrift
- eISSN
- 2719-9509
- Erstveröffentlichung
- 01 Jan 1992
- Erscheinungsweise
- 4 Hefte pro Jahr
- Sprachen
- Englisch
Suche
- Uneingeschränkter Zugang
Pyrolysis - Field lonization Mass Spectrometry - A New Method for Direct, Rapid Characterization of Tobacco
Seitenbereich: 219 - 227
Zusammenfassung
For the first time, pyrolysis - field ionization (Py-FI) mass spectra of the tobacco blends of three different cigarette brands have been recorded in the mass range up to 1000 mass units and evaluated by operational fingerprinting techniques. Due to the high reproducibility of the applied methods, all three tobacco blends could be differentiated clearly with several univariate or multivariate statistical methods. Feature scaling with Fisher ratios revealed that the signal at m/z 93, mainly due to aniline, is the most suited to distinguishing the tobacco blends analysed. Principal component analysis showed the variety of pyrolytic reactions during the thermal decomposition of tobacco in high vacuum. It revealed that, in addition to aniline, lignin-related signals can also be used for a clear differentiation. From the whole pattern of Py-FI mass spectrum, nearest-neighbour relationships are visualized by the non-linear mapping technique and further classification of tobacco blends is obtained by hierarchical cluster analysis. A thorough chemical interpretation of the data obtained should give new insights into the structure of tobacco and its pyrolytic decomposition. Pyrolysis - soft ionization mass spectrometry in combination with pattern recognition techniques appears to provide a useful tool for future investigations connected with the quality control of commercial tobacco products.
- Uneingeschränkter Zugang
The Contribution of Sucrose Esters to Tobacco Smoke Composition
Seitenbereich: 229 - 238
Zusammenfassung
Sucrose esters, principally the 6-O-acetyl-2,3,4-tri-O-(3-methylvaleryl)-a-D-glucopyranosyl-b-D-fructofuran-oside isomer, isolated from the cuticular waxes of green T.I. 165 tobacco leaf, were evaluated as enhancers of 3-methylvaleric acid in the smoke of a tobacco deficient in this important flavor compound. Analyses of the products from semi-micro pyrolyses of sucrose and isolated sucrose esters, over a temperature range of 250°C - 850°C, showed that free sucrose produced 5-hydroxy-methylfurfural as the major component, whereas the ester isolate yielded 3-methylvaleric acid and lesser amounts of isomeric C4 and C5 aliphatic acids. Incorporation of sucrose ester isolate of T.I. 165 leaf into cigarettes prepared from flue-cured NC 2326 tobacco, the smoke of which is essentially devoid of 3-methylvaleric acid, resulted in a total particulate matter with enhanced levels of this compound. The data indicated that addition of approximately 2 mg of sucrose ester isolate per cigarette produced levels of 3-methylvaleric acid in the smoke of NC 2326 cigarettes that were comparable to levels observed in the smoke from cigarettes containing all T.I. 165 or blended Turkish tobacco.
- Uneingeschränkter Zugang
Determination of Catechol in Cigarette Smoke Condensate by High-Performance Liquid Chromatography (HPLC) Analysis with an Automated Precolumn Sample Preparation
Seitenbereich: 239 - 242
Zusammenfassung
A procedure has been developed for a simple and specific determination of catechol in cigarette smoke condensate. The analysis is performed by high-performance liquid chromatography (HPLC) with column switching between a precolumn and an analytical column. Catechol is separated from most of the condensate components by selective adsorption on a dihydroxyboryl silica gel precolumn. It is then determined without interference on a reverse-phase (C18) column. By column switching this procedure is run automatically within 15 min. The method is well suited for the routine measurement of a large number of samples, since it allows condensate solutions to be injected directly into the analysis system without prior laborious and time-consuming clean-up procedures.
- Uneingeschränkter Zugang
The Efficiencies of Cellulose Acetate Filters
Seitenbereich: 243 - 253
Zusammenfassung
Cigarette filters remove both particles and condensable vapours from tobacco smoke aerosols. The particulate contribution to filtration can be isolated by allowing the smoke aerosol to attain thermal equilibrium before it is introduced to the filter. Such experiments show the effects of filter length, filter pressure drop, and aerosol flow rate on particulate filtration. The relative roles of diffusion, impaction, and interception on particle removal have been examined. The extent to which vapour condensation occurs in filters has been found to be dependent on the length to which the tobacco rod has been smoked and independent of the pressure drop of the filter.
- Uneingeschränkter Zugang
Determination of Triacetin in Cigarette Filters by Pulsed Nuclear Magnetic Resonance Spectroscopy - Bestimmung von Triacetin in Zigarettenfiltern mit Hilfe der gepulsten Kernresonanzspektroskopie
Seitenbereich: 255 - 264
Zusammenfassung
Our investigations show that pulsed nuclear magnetic resonance spectroscopy (p-NMR) is a suitable method of determining the triacetin content of freshly produced filter rods. The table-top pulse spectrometer tested in filter rod production distinguishes itself by the fact that it enables exact and reproducible direct measurements of whole filter rods to be made in seconds. There is no need for the whole process of preparing samples; after measurement the filters can be fed back into the production process. With the measuring method we have developed triacetin can be determined completely automatically, independent of sample weight and to a large extent independent of the moisture content of the filter material. The period of time between the triacetin application and the p-NMR measurement should be as short as possible and accurately reproducible.
- Uneingeschränkter Zugang
Seasonal Nutrient Contents in Grey and Non-grey Flue-cured Tobacco
Seitenbereich: 265 - 269
Zusammenfassung
Analysis of leaf samples at intervals between late June and early August of 1979 and 1980 indicated lower mean concentrations of nitrogen and potassium, and higher mean concentrations of iron and manganese in grey than in non-grey (normal) tobacco. In grey tobacco, the concentrations of potassium and iron were present in deficient and toxic levels, respectively, in the majority of the samples throughout the whole sampling periods. Although symptoms on leaves resembled those of iron toxicity, changes in intensity of grey symptoms during sampling were associated with severity of potassium deficiency.
- Uneingeschränkter Zugang
Recommended Plant Protecting Agents - Current Strategies in 22 Important Tobacco Exporting Countries
Seitenbereich: 271 - 280
Zusammenfassung
A review is given of the present lists of crop protectants recommended for use on tobacco in the 22 countries which export the majority of tobacco to the Federal Republic of Germany. The information is of significance in the overall monitoring and control of chemical residues on imported tobacco and in establishing priorities in developing methods of residue analysis for these chemicals.