- Détails du magazine
- Première publication
- 01 Jan 1992
- Période de publication
- 4 fois par an
- Accès libre
Pages: 229 - 246
Residues of inorganic insecticides used on tobacco have decreased to the extent that they are primarily of academic interest only. Organic pesticides used for control of pests, including sucker growth, can often be detected at high levels during the early phases in the culture of tobacco due to the large surface-to-weight ratio characteristic of leafy products. Residues of 100 ppm are not uncommon for stable pesticides on green tobacco ready for harvest and even pesticides which normally dissipate quickly after treatment, as parathion, may exceed 4 ppm following normal treatment. During the flue-curing process, from 40-99 per cent of the residues disappear. Air-curing is much less effective in destroying the residues as would be expected. During smoking of cigarettes 80-90 per cent of such stable compounds as the chlorinated hydrocarbons is decomposed or transferred to the sidestream smoke whereas less stable pesticides, as phosphate insecticides or carbamate fungicides, are normally detected in mainstream smoke at levels less than 5 per cent of that present in the cigarette before smoking. The fate of TDE, the most common insecticide found in mainstream cigarette smoke from commercial cigarettes, appears to follow the same route of degradation in mammalian systems whether inhaled or introduced orally. The levels of pesticides found in mainstream smoke of commercial cigarettes, or expected from recommended treatment, are below the tolerance ascribed on food by several countries. However, additional research is needed to clarify the contribution of applied pesticides from the same compounds produced pyrolytically during cigarette consumption. Continuous surveillance of manufactured tobacco for pesticide residues, increased research on the isolation and identity of decomposition products in mainstream smoke, and augmentation with non-pesticidal or decreased pesticidal methods should be encouraged.
- Accès libre
The Determination of Benzofuran in Tobacco Smoke / Über das Vorkommen von Benzofuranen im Tabakrauch
Pages: 247 - 249
Benzo-[b]-furan as well as three isomers of methylbenzo-[b]-furan and three isomers of dimethylbenzo-[b]-furan have been detected in the smoke of normal blended cigarettes by a combination of gas chromatography and mass spectrometry. The isomeric compounds could not be exactly identified on the basis of the mass spectra alone.
- Accès libre
The Determination of Hydroaromatic Compounds in Tobacco Smoke / Über das Vorkommen von Hydroaromaten im Tabakrauch
Pages: 250 - 252
Indan, 1-methylindan, 2-methylindan, 1,2,3,4-tetrahydronaphthalene, 1-methyl5,6,7,8-tetrahydronaphthalene, 2-methyl-1,2,3,4-tetrahydronaphthalene, and benzyl cyanide have, for the first time, been isolated from the smoke of normal blended cigarettes by a combination of gas chromatography and mass spectrometry. Four isomers of methylindan, four isomers of dimethylindan, one ethylindan, and one methyltetralin could not be exactly identified on the basis of the mass spectra alone.
- Accès libre
Pages: 253 - 263
A method was developed for the enrichment of carbazoles from cigarette smoke. It involves a distribution between two solvent systems, column chromatography, and, finally, separation of a carbazole concentrate into individual components by gas chromatography. The major components in the chromatogram were collected after the final separation and were then identified by mass spectra. Since the latter method showed similar fragmentation patterns for five carbazoles and 2- and 3-phenylindoles, mass spectra appeared especially suitable for their identification. Carbazole, 1-methylcarbazole, 4-methylcarbazole, 3-phenylindole, a mixture of 2- and 3-methylcarbazole and, tentatively, a dimethyl- or ethylcarbazole and 2-phenylindole were identified in cigarette smoke. The relevancy of mass spectra for the identification of carbazoles and 2- and 3-phenylindoles is discussed. For the quantitative analysis of carbazoles and 3-phenylindole, carbazole-10-C14 was employed as internal standard. The radioactive compound was synthesized on a microscale from phenylhydrazine-1-C14 by the Borsche method with a 58% yield. The smoke of 100 U.S. nonfilter cigarettes of 85 mm length contains 100 µg of carbazole, 23 µg of 1-methylcarbazole, 19 µg of 2- and 3-methylcarbazole, 9.8 µg of 4-methylcarbazole and 31 µg of 3-phenylindole. The concentrations of the tentatively identified dimethyl-, or ethylcarbazole and 2-phenylindole were below 1.0 µg.
- Accès libre
The Determination of the Water Content in Cigarette Smoke Condensate Using a Karl Fischer Titrator / Wasserbestimmung im Rauchkondensat nach Karl Fischer mit einer halbautomatischen Apparatur
Pages: 264 - 267
The current method of determination of the water content of cigarette smoke condensate was improved by using a Karl Fischer titrator with automatic end-point stop. The overall procedure thus becomes faster (the titration time is less than 2 minutes), easier (no supervision is needed during the titration) and better reproducible (coefficient of variation 2.5 % on the amount of water determined). In these three criterions, the automated Karl Fischer method is superior to a gas-chromatographic procedure having served as a method of comparison.